U.S. patent application number 15/595755 was filed with the patent office on 2017-11-16 for solid electrolyte separator bonding agent.
The applicant listed for this patent is QuantumScape Corporation. Invention is credited to Zhebo CHEN, Niall DONNELLY, Tim HOLME, Deepika SINGH.
Application Number | 20170331092 15/595755 |
Document ID | / |
Family ID | 58772975 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170331092 |
Kind Code |
A1 |
CHEN; Zhebo ; et
al. |
November 16, 2017 |
SOLID ELECTROLYTE SEPARATOR BONDING AGENT
Abstract
Set forth herein are electrochemical cells which include a
negative electrode current collector, a lithium metal negative
electrode, an oxide electrolyte membrane, a bonding agent layer, a
positive electrode, and a positive electrode current collector. The
bonding agent layer advantageously lowers the interfacial impedance
of the oxide electrolyte at least at the positive electrode
interface and also optionally acts as an adhesive between the solid
electrolyte separator and the positive electrode interface. Also
set forth herein are methods of making these bonding agent layers
including, but not limited to, methods of preparing and depositing
precursor solutions which form these bonding agent layers. Set
forth herein, additionally, are methods of using these
electrochemical cells.
Inventors: |
CHEN; Zhebo; (San Jose,
CA) ; DONNELLY; Niall; (San Jose, CA) ; HOLME;
Tim; (San Jose, CA) ; SINGH; Deepika; (San
Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QuantumScape Corporation |
San Jose |
CA |
US |
|
|
Family ID: |
58772975 |
Appl. No.: |
15/595755 |
Filed: |
May 15, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62336474 |
May 13, 2016 |
|
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62448294 |
Jan 19, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 2300/0071 20130101;
H01M 2/1653 20130101; H01M 2/168 20130101; H01M 4/382 20130101;
H01M 10/0468 20130101; H01M 2004/027 20130101; H01M 10/0583
20130101; H01M 10/052 20130101; H01M 4/1399 20130101; Y02E 60/10
20130101; H01M 4/137 20130101; H01M 10/0562 20130101 |
International
Class: |
H01M 2/16 20060101
H01M002/16; H01M 4/1399 20100101 H01M004/1399; H01M 4/137 20100101
H01M004/137; H01M 10/04 20060101 H01M010/04; H01M 10/052 20100101
H01M010/052; H01M 10/0583 20100101 H01M010/0583 |
Claims
1. An electrochemical stack, comprising: a lithium metal (Li)
negative electrode, a positive electrode, an electrolyte separator,
and a bonding layer; wherein the bonding layer comprises a lithium
salt, a polymer, and a solvent; wherein the electrolyte separator
is in direct contact with the Li metal negative electrode; and
wherein the bonding layer directly contacts, and is positioned
between, the electrolyte separator and the positive electrode.
2. The electrochemical stack of claim 1, wherein electrolyte
separator is an oxide electrolyte separator.
3. The electrochemical stack of claim 1, wherein the Li negative
electrode comprises a layer of Li metal having a thickness from 1
nm to 30 .mu.m in the fully discharged state.
4. The electrochemical stack of claim 1, wherein the Li metal
negative electrode comprises a layer of Li metal having a thickness
from 1 .mu.m to 50 .mu.m in the fully charged state.
5. The electrochemical stack of claim 1, wherein the electrolyte
separator has a surface roughness, on at least one surface, from
about 0.01 .mu.m to 10 .mu.m.
6. The electrochemical stack of claim 1, wherein the electrolyte
separator has a surface roughness, on at least one surface, from
about 0.01 .mu.m to 5 .mu.m.
7. The electrochemical stack of claim 1, wherein the electrolyte
separator has a surface roughness, on at least one surface, from
about 0.01 .mu.m to 2 .mu.m.
8. The electrochemical stack of claim 1, wherein the electrolyte
separator has a surface roughness from about 0.1 .mu.m to 10 .mu.m
at the surface that interfaces the electrolyte separator and the Li
metal negative electrode.
9. The electrochemical stack of claim 1, wherein the electrolyte
separator has a density greater than 95% of its theoretical
density.
10. The electrochemical stack of claim 9, wherein the electrolyte
separator has a density greater than 95% of its theoretical density
as determined by scanning electron microscopy (SEM).
11. The electrochemical stack of claim 9, wherein the electrolyte
separator has a density greater than 95% of its theoretical density
as measured by the Archimedes method.
12. The electrochemical stack of claim 1, wherein the electrolyte
separator has a surface flatness of 0.1 .mu.m to about 50
.mu.m.
13. The electrochemical stack of claim 1, wherein the polymer in
the bonding layer is selected from the group consisting of
polyacrylonitrile (PAN), polypropylene, polyethylene oxide (PEO),
polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyvinyl
pyrrolidone (PVP), polyethylene oxide poly(allyl glycidyl ether)
PEO-AGE, polyethylene oxide 2-methoxyethoxy)ethyl glycidyl ether
(PEO-MEEGE), polyethylene oxide 2-methoxyethoxy)ethyl glycidyl
poly(allyl glycidyl ether) (PEO-MEEGE-AGE), polysiloxane,
polyvinylidene fluoride (PVDF), polyvinylidene fluoride
hexafluoropropylene (PVDF-HFP), ethylene propylene (EPR), nitrile
rubber (NPR), styrene-butadiene-rubber (SBR), polybutadiene
polymer, polybutadiene rubber (PB), polyisobutadiene rubber (PIB),
polyisoprene rubber (PI), polychloroprene rubber (CR),
acrylonitrile-butadiene rubber (NBR), polyethyl acrylate (PEA),
polyvinylidene fluoride (PVDF), and polyethylene.
14. The electrochemical stack of claim 13, wherein the polymer in
the bonding layer is polyacrylonitrile (PAN) or polyvinylidene
fluoride hexafluoropropylene (PVDF-HFP).
15. The electrochemical stack of claim 13, wherein the polymer in
the bonding layer is selected from the group consisting of PAN,
PVDF-HFP, PMMA, PVC, PVP, PEO, and combinations thereof.
16. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is selected from the group consisting of
LiPF.sub.6, LiBOB, LiBETI, LiTFSi, LiBF.sub.4, LiClO.sub.4,
LiAsF.sub.6, LiFSI, LiAsF.sub.6, LiClO.sub.4, LiI, LiBF.sub.4, and
a combination thereof.
17. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is selected from the group consisting of
LiPF.sub.6, LiBOB, LFTSi, and a combination thereof.
18. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is LiPF.sub.6 at a concentration of 0.5 M to 2
M.
19. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is LiTFSI at a concentration of 0.5 M to
2M.
20. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is LiBF.sub.4 at a concentration of 0.5 M to
2M.
21. The electrochemical stack of claim 1, wherein the lithium salt
in the bonding layer is present at a concentration from 0.01 M to
10 M.
22. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is selected from the group consisting of ethylene
carbonate (EC), diethylene carbonate or diethyl carbonate (DC),
dimethyl carbonate (DMC), ethyl-methyl carbonate (EMC),
tetrahydrofuran (THF), .gamma.-Butyrolactone (GBL), fluoroethylene
carbonate (FEC), fluoromethyl ethylene carbonate (FMEC),
trifluoroethyl methyl carbonate (F-EMC), fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane(F-EPE),
fluorinated cyclic carbonate (F-AEC), propylene carbonate (PC),
dioxolane, acetonitrile (ACN), succinonitrile, adiponitrile,
hexanedinitrile, pentanedinitrile, acetophenone, isophorone,
benzonitrile, dimethyl sulfate, prop-1-ene-1,3-sultone (PES),
dimethyl sulfoxide (DMSO), ethyl-methyl carbonate, ethyl acetate,
methyl butyrate, dimethyl ether (DME), diethyl ether, propylene
carbonate, dioxolane, glutaronitrile, gamma butyl-lactone, and
combinations thereof.
23. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is a 1:1 w/w mixture of EC:PC.
24. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is a mixture of EC:EMC.
25. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is a mixture of EC:sulfolane.
26. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is a mixture of succinonitrile and
glutaronitrile.
27. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer is PES.
28. The electrochemical stack of claim 22, wherein the amount of
solvent in the bonding layer is the amount remaining after the
bonding layer is dried.
29. The electrochemical stack of claim 22, wherein the amount of
solvent in the bonding layer is the minimum amount of solvent
required to solvate the lithium salt.
30. The electrochemical stack of claim 1, wherein the bonding layer
lowers the interfacial impedance between the electrolyte separator
and the positive electrode than it otherwise would be in the
absence of the bonding layer.
31. The electrochemical stack of claim 1, wherein the interfacial
impedance between the electrolyte separator and the positive
electrode is less than 50 .OMEGA.cm.sup.2 at 50.degree. C.
32. The electrochemical stack of claim 1, wherein the interfacial
impedance between the electrolyte separator and the positive
electrode is less than 25 .OMEGA.cm.sup.2 at 50.degree. C.
33. The electrochemical stack of claim 1, wherein the interfacial
impedance between the electrolyte separator and the positive
electrode is less than 10 .OMEGA.cm.sup.2 at 50.degree. C.
34. The electrochemical stack of claim 1, wherein the interfacial
impedance between the electrolyte separator and the positive
electrode is less than 5 .OMEGA.cm.sup.2 at 50.degree. C.
35. The electrochemical stack of claim 1, wherein the positive
electrode comprises a lithium intercalation material, a lithium
conversion material, or a combination thereof.
36. The electrochemical stack of claim 35, wherein the lithium
intercalation material is selected from the group consisting of a
nickel manganese cobalt oxide (NMC), a nickel cobalt aluminum oxide
(NCA), Li(NiCoAl)O.sub.2, a lithium cobalt oxide (LCO), a lithium
manganese cobalt oxide (LMCO), a lithium nickel manganese cobalt
oxide (LMNCO), a lithium nickel manganese oxide (LNMO),
Li(NiCoMn)O.sub.2, LiMn.sub.2O.sub.4, LiCoO.sub.2,
LiMn.sub.2-zNi.sub.aO.sub.4, wherein a is from 0 to 2, or
LiMPO.sub.4, wherein M is Fe, Ni, Co, and Mn.
37. The electrochemical stack of claim 36, wherein the lithium
conversion material is selected from the group consisting of
FeF.sub.2, NiF.sub.2, FeO.sub.xF.sub.3-2x, FeF.sub.3, MnF.sub.3,
CoF.sub.3, CuF.sub.2 materials, alloys thereof, and combinations
thereof.
38. The electrochemical stack of claim 1, wherein the positive
electrode further comprises a catholyte.
39. The electrochemical stack of claim 38, wherein the catholyte is
a gel electrolyte.
40. The electrochemical stack of claim 39, wherein the positive
electrode comprises a gel catholyte which has the same composition
as the bonding layer.
41. The electrochemical stack of claim 38, wherein the positive
electrode comprises a gel catholyte comprising: a solvent selected
from the group consisting of ethylene carbonate (EC), propylene
carbonate (PC), dimethyl carbonate (DMC), methylene carbonate, and
combinations thereof; a polymer selected from the group consisting
of PVDF-HFP, PAN, and combinations thereof; and a salt selected
from the group consisting of LiPF.sub.6, LiBOB, and LFTSi.
42. The electrochemical stack of claim 1, wherein the bonding layer
is a phase inversion gel electrolyte.
43. The electrochemical stack of claim 1, wherein the positive
electrode comprises a phase-inversion gel catholyte.
44. The electrochemical stack of claim 38, wherein the positive
electrode comprises a phase inversion gel catholyte comprising: a
polymer selected from the group consisting of PVDF-HFP and PAN; a
non-solvent selected from toluene, acetone, and combination
thereof; and a salt selected from the group consisting of
LiPF.sub.6, LiBOB, and LFTSi.
45. The electrochemical stack of claim 1, wherein the positive
electrode further comprises a binder selected from the group
consisting of polypropylene (PP), atactic polypropylene (aPP),
isotactic polypropylene (iPP), ethylene propylene rubber (EPR),
ethylene pentene copolymer (EPC), polyethylene oxide (PEO), PEO
block copolymers, polyethylene glycol, polyisobutylene (PIB),
styrene butadiene rubber (SBR), a polyolefin,
polyethylene-co-poly-1-octene (PE-co-PO) copolymer,
PE-co-poly(methylene cyclopentane) (PE-co-PMCP) copolymer,
stereoblock polypropylenes, polypropylene polymethylpentene
copolymer, acrylics, acrylates, polyvinyl butyral, vinyl polymers,
cellulose polymers, resins, polyvinyl alcohol, polymethyl
methacrylate, polyvinyl pyrrolidone, polyacrylamide, silicone,
PVDF, PVDF-HFP, PAN, and combinations thereof.
46. The electrochemical stack of claim 1, wherein the positive
electrode comprises an electronically conductive source of
carbon.
47. The electrochemical stack of claim 1, wherein the positive
electrode comprises a solid catholyte and either a lithium
intercalation material or a lithium conversion material; wherein
each of the catholyte, lithium intercalation material or a lithium
conversion material independently has a d.sub.50 particle size from
about 0.1 .mu.m to 5 .mu.m.
48. The electrochemical stack of claim 1, wherein the electrolyte
separator is selected from the group consisting of a
lithium-stuffed garnet, a sulfide electrolyte doped with oxygen, a
sulfide electrolyte comprising oxygen, a lithium aluminum titanium
oxide, a lithium aluminum titanium phosphate, a lithium aluminum
germanium phosphate, a lithium aluminum titanium oxy-phosphate, a
lithium lanthanum titanium oxide perovskite, a lithium lanthanum
tantalum oxide perovskite, a lithium lanthanum titanium oxide
perovskite, an antiperovskite, a LISICON, a LI--S--O--N, lithium
aluminum silicon oxide , a Thio-LISICON, a lithium-substituted
NASICON, a LIPON, or a combination, mixture, or multilayer
thereof.
49. The electrochemical stack of claim 48, wherein the electrolyte
separator is lithium lanthanum titanium oxide characterized by the
empirical formula, Li.sub.3xLa.sub.2/3-xTiO.sub.3, wherein x is a
rational number from 0 to 2/3.
50. The electrochemical stack of claim 48, wherein the electrolyte
separator is lithium lanthanum titanium oxide characterized by the
empirical formula, Li.sub.3xLa.sub.2/3-xTi.sub.jTa.sub.kO.sub.3,
wherein x is a rational number from 0 to 2/3, and wherein
subscripts j+k=1, and j and k, independently in each instance, are
a rational number from 0 to 1.
51. The electrochemical stack of claim 48, wherein the electrolyte
separator is lithium lanthanum titanium oxide characterized by a
perovskite crystal structure.
52. The electrochemical stack of claim 42, wherein the electrolyte
separator is an antiperovskite characterized by the empirical
formula, Li.sub.3OX wherein X is Cl, Br, or combinations
thereof.
53. The electrochemical stack of claim 42, wherein the electrolyte
separator is LISICON characterized by the empirical formula,
Li(Me'.sub.x,Me''.sub.y)(PO.sub.4) wherein Me' and Me'' are
selected from Si, Ge, Sn or combinations thereof; and wherein
0.ltoreq.x.ltoreq.1; wherein 0.ltoreq.y.ltoreq.1, and wherein
x+y=1.
54. The electrochemical stack of claim 42, wherein the electrolyte
separator is thio-LISICON characterized by the empirical formula,
Li.sub.3.25Ge.sub.0.25P.sub.0.75S.sub.4.
55. The electrochemical stack of claim 48, wherein the electrolyte
separator is thio-LISICON characterized by the empirical formula,
Li.sub.4-xM.sub.1-xP.sub.xS.sub.4 or Li.sub.10MP.sub.2S.sub.12,
wherein M is selected from Si, Ge, Sn, or combinations thereof; and
wherein 0.ltoreq.x.ltoreq.1.
56. The electrochemical stack of claim 42, wherein the electrolyte
separator is lithium aluminum titanium phosphate characterized by
the empirical formula, Li.sub.1+aAl.sub.bTi.sub.2-c(PO.sub.4),
wherein 0.ltoreq.a.ltoreq.2; 0.ltoreq.b.ltoreq.2; and
0.ltoreq.c.ltoreq.2.
57. The electrochemical stack of claim 42, wherein the electrolyte
separator is lithium aluminum germanium phosphate characterized by
the empirical formula,
Li.sub.1.5Al.sub.0.5Ge.sub.1.5(PO.sub.4).
58. The electrochemical stack of claim 42, wherein the electrolyte
separator is LI--S--O--N characterized by the empirical formula,
Li.sub.xS.sub.yO.sub.zN.sub.w, wherein x, y, z, and w, are each,
independently, a rational number from 0.01 to 1.
59. The electrochemical stack of claim 1, wherein the electrolyte
separator is characterized by the empirical formula
Li.sub.xLa.sub.3Zr.sub.2O.sub.h+yAl.sub.2O.sub.3, wherein
3.ltoreq.x.ltoreq.8, 0.ltoreq.y.ltoreq.1, and 6.ltoreq.h.ltoreq.15;
and wherein subscripts x and h, and coefficient y is selected so
that the electrolyte separator is charge neutral.
60. The electrochemical stack of claim 59, wherein the electrolyte
separator is doped with Ga, Nb, or Ta.
61. The electrochemical stack of claim 1, wherein the electrolyte
separator isolates the positive electrode from the negative
electrode.
62. The electrochemical stack of claim 1, wherein the electrolyte
separator physically decouples the positive electrode from the
negative electrode.
63. The electrochemical stack of claim 1, wherein the electrolyte
separator has a top or bottom surface that has less than 5 atomic %
of an amorphous material comprising carbon and oxygen.
64. The electrochemical stack of claim 63, wherein the amorphous
material is lithium carbonate, lithium hydroxide, lithium oxide,
lithium peroxide, a hydrate thereof, an oxide thereof, or a
combination thereof.
65. The electrochemical stack of claim 1, wherein the bonding layer
is characterized by a thickness of about 1 nm to about 5 .mu.m.
66. The electrochemical stack of claim 1, wherein the Li negative
electrode is characterized by a thickness of about 10 nm to about
50 .mu.m.
67. The electrochemical stack of claim 1, wherein the oxide
separator is characterized by a thickness of about 0.1 .mu.m to
about 100 .mu.m.
68. The electrochemical stack of claim 1, wherein the oxide
separator is characterized by a thickness of about 10 .mu.m to
about 50 .mu.m.
69. The electrochemical stack of claim 1, wherein the bonding layer
penetrates into the positive electrode.
70. The electrochemical stack of claim 1, wherein the bonding layer
penetrates into the positive electrode at least 10% of the
thickness of the positive electrode.
71. The electrochemical stack of claim 1, wherein the bonding layer
contacts the catholyte in the positive electrode.
72. The electrochemical stack of claim 1, wherein the bonding layer
does not creep around the electrolyte separator.
73. The electrochemical stack of claim 1, wherein the bonding layer
does not comprise components which volatilize and diffuse around
the electrolyte separator to contact the Li metal negative
electrode.
74. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer have a vapor pressure less than about 80 Torr at
20.degree. C.
75. The electrochemical stack of claim 1, wherein the solvent in
the bonding layer has a boiling point above 80.degree. C. at one
atmosphere.
76. The electrochemical stack of claim 1, wherein the electrolyte
separator is free of pin-holes.
77. The electrochemical stack of claim 1, wherein the electrolyte
separator is free of surface defects.
78. The electrochemical stack of claim 1, wherein diameter of the
electrolyte separator is greater than the diameter of the lithium
metal negative electrode.
79. The electrochemical stack of claim 1, wherein diameter of the
electrolyte separator is greater than the diameter of the positive
electrode.
80. The electrochemical stack of claim 1, wherein width or diameter
of the electrolyte separator is greater than either of the width or
diameter, respectively, of the lithium metal negative electrode or
of the positive electrode.
81. The electrochemical stack of claim 1, wherein width or diameter
of the electrolyte separator is greater than the width or diameter,
respectively, of the lithium metal negative electrode.
82. The electrochemical stack of claim 1, wherein width or diameter
of the electrolyte separator is greater than the width or diameter,
respectively, of the positive electrode.
83. The electrochemical stack of claim 1, wherein width or diameter
of the electrolyte separator is greater than both the width and
diameter, respectively, of the lithium metal negative electrode and
positive electrode.
84. The electrochemical stack of claim 1, wherein the electrolyte
separator has raised edges which protect the bonding layer, or its
constituent components, from creeping around the electrolyte
separator.
85. The electrochemical stack of claim 1, wherein the electrolyte
separator has coated edges which protect the bonding layer from
contacting the Li metal negative electrode.
86. The electrochemical stack of claim 85, wherein the coated edges
comprise a coating selected from parylene, polypropylene,
polyethylene, alumina, Al.sub.2O.sub.3, ZrO.sub.2, TiO.sub.2,
SiO.sub.2, a binary oxide, La.sub.2Zr.sub.2O.sub.7, a lithium
carbonate species, or a glass, wherein the glass is selected from
SiO.sub.2--B.sub.2O.sub.3, or Al.sub.2O.sub.3.
87. The electrochemical stack of claim 1, wherein the electrolyte
separator has tapered edges which protect the bonding layer from
creeping around the electrolyte separator.
88. The electrochemical stack of claim 1, wherein the electrolyte
separator has a thickness between about 10 nm and 50 .mu.m; the
bonding layer has a thickness between about 1 .mu.m and 20 .mu.m;
and the positive electrode, exclusive of the current collector, has
a thickness between about 5 .mu.m and 150 .mu.m.
89. A free standing film comprising a spin-coated gel electrolyte,
wherein the phase inversion gel electrolyte comprises a lithium
salt, a polymer, and a solvent; and wherein the phase inversion gel
electrolyte has a porosity of at least 20%.
90-100. (canceled)
101. A free standing film comprising a phase inversion gel
electrolyte, wherein the phase-inversion gel electrolyte comprises
a lithium salt, a solvent, and a polymer and wherein the phase
inversion gel electrolyte has a porosity of at least 20%.
102-112. (canceled)
113. A method of making an electrochemical device, comprising,
providing a positive electrode, providing a free standing film as
set forth in claim 101; bonding, adhering, or laminating the free
standing film to the positive electrode to form a composite;
providing a lithium metal negative electrode; and bonding,
adhering, or laminating the lithium metal negative electrode to the
composite, thereby making an electrochemical device.
114. The electrochemical stack of claim 1, wherein the electrolyte
separator protects the Li metal negative electrode from exposure to
the polymer or to the solvent in the bonding layer.
115. The electrochemical stack of claim 48, wherein the electrolyte
separator is Li.sub.4-xGe.sub.1-xP.sub.xS.sub.4 where
0.2.ltoreq.x.ltoreq.0.8.
116. An electrochemical stack, comprising: a lithium metal (Li)
negative electrode, a positive electrode, an electrolyte separator,
and a bonding layer comprising a lithium salt, a polymer, and a
solvent; wherein the electrolyte separator is in direct contact
with the Li metal negative electrode; wherein the bonding layer
directly contacts, and is positioned between, the electrolyte
separator and the positive electrode; and wherein the bonding layer
is disposed on the side of the electrolyte separator not in contact
with the Li metal negative electrode.
117. (canceled)
118. An electrochemical stack, comprising: a lithium metal (Li)
negative electrode, a positive electrode, a sulfide electrolyte
separator, and a bonding layer; wherein the bonding layer comprises
a lithium salt, a polymer, and a solvent; wherein the electrolyte
separator is in direct contact with the Li metal negative
electrode; and wherein the bonding layer directly contacts, and is
positioned between, the electrolyte separator and the positive
electrode.
119. An electrochemical stack, comprising: a lithium metal (Li)
negative electrode, a positive electrode, a borohydride electrolyte
separator, and a bonding layer; wherein the bonding layer comprises
a lithium salt, a polymer, and a solvent; wherein the borohydride
electrolyte separator is in direct contact with the Li metal
negative electrode; and wherein the bonding layer directly
contacts, and is positioned between, the borohydride electrolyte
separator and the positive electrode.
Description
BACKGROUND
[0001] This application claims priority to, and the benefit of, US
Provisional Patent Application No. 62/336,474, filed, May 13, 2016,
entitled SOLID ELECTROLYTE SEPARATOR BONDING AGENT, and US
Provisional Patent Application No. 62/448,294, filed Jan. 19, 2017,
entitled SOLID ELECTROLYTE SEPARATOR BONDING AGENT, the entire
contents of each of which are herein incorporated by reference in
their entirety for all purposes.
[0002] In a rechargeable Li.sup.+ ion battery, Li.sup.+ ions move
from a negative electrode to a positive electrode during discharge
and in the opposite direction during charge. This process produces
electrical energy (Energy=Voltage.times.Current) in a circuit
connecting the electrodes, which is electrically insulated from,
but parallel to, the Li.sup.+ ion conduction path. The battery's
voltage (V versus Li) is a function of the chemical potential
difference for Li situated in the positive electrode as compared to
the negative electrode and is maximized when Li metal is used as
the negative electrode. An electrolyte physically separates and
electrically insulates the positive and negative electrodes while
also providing a conduction medium for Li.sup.+ ions. The
electrolyte ensures that when Li metal oxidizes, at the negative
electrode during discharge (e.g., LiLi.sup.++e.sup.-), and produces
electrons, these electrons conduct between the electrodes by way of
an external circuit which is not the same pathway taken by the
Li.sup.+ ions.
[0003] Conventional rechargeable batteries use liquid electrolytes
to separate the positive and negative electrodes. However, liquid
electrolytes suffer from several problems including flammability
during thermal runaway, outgassing at high voltages, and chemical
incompatibility with lithium metal negative electrodes. As an
alternative, solid electrolytes have been proposed for next
generation rechargeable batteries. For example, Li.sup.+
ion-conducting ceramic oxides, such as lithium-stuffed garnets,
have been considered as electrolyte separators. See, for example,
US Patent Application Publication No. 2015/0099190, published Apr.
9, 2015, and filed Oct. 7, 2014, titled GARNET MATERIALS FOR LI
SECONDARY BATTERIES AND METHODS OF MAKING AND USING GARNET
MATERIALS; U.S. Pat. Nos. 8,658,317; 8,092,941; and 7,901,658; also
U.S. Patent Application Publication Nos. 2013/0085055;
2011/0281175; 2014/0093785; and 2014/0170504; also Bonderer, et al.
"Free-Standing Ultrathin Ceramic Foils," Journal of the American
Ceramic Society, 2010, 93(11):3624-3631; and Murugan, et al., Angew
Chem. Int. Ed. 2007, 46, 7778-7781), the entire contents of each of
these publications are incorporated by reference in their entirety
for all purposes.
[0004] Solid electrolytes should reduce a battery's total weight
and volume when paired with a lithium metal anode, when compared to
a liquid electrolyte paired with a graphite anode, and thereby
should increase its gravimetric and volumetric energy density.
Despite these advantages, solid electrolytes are still insufficient
in several regards for commercial applications. For example, when a
battery with a lithium metal negative electrode charges and
discharges, it expands and contracts as the lithium conducts
between the electrodes. This expansion and contraction can lead to
delamination of a solid electrolyte separator, positioned between a
positive and negative electrode, from either or both of the
positive and negative electrodes. Moreover, even in the absence of
delamination, solid interfaces tend not to perfectly align with
each other. If a solid lithium metal negative electrode is
laminated to a solid electrolyte, and the solid electrolyte (i.e.,
separator), on the opposing side, is laminated to a positive
electrode, each solid interface (Li-separator &
Separator-Cathode) may have insufficient electrical contact due to
areas where one solid interface does not perfectly align and
contact another solid interface. When solid electrolytes are used
to separate solid positive and negative electrodes, gaps or areas
of non-contact may build up between the solid interfaces, e.g., the
interface of the electrolyte and the positive electrode. Areas of
non-contact between the solid electrolyte and the positive
electrode result in impedance rises which reduce a battery's power
and capacity. To date and the best of Applicant's knowledge, there
are no public disclosures of commercially viable solid electrolyte
separators which interface with a solid positive electrode with a
sufficiently low interfacial resistance suitable for a commercial
application.
[0005] When, for example, a solid separator such as a
lithium-stuffed garnet electrolyte monolith contacts a positive
electrode, there may be interfacial impedance between the solid
electrolyte and the positive electrode due to poor wetting of the
positive electrode, or its catholyte, onto the solid electrolyte
surface, low ion-conductivity in either the separator or the
electrode, or chemical reactions between the positive electrode and
the solid electrolyte which produce side products detrimental to
electrochemical performance. To address some of these challenges,
certain researchers have attempted to combine liquid and gel
electrolytes with lithium-stuffed garnets. See, for example, K.
Yoshima, et al., Journal of Power Sources, 302 (2016) 283-290.
However, no reported methods to date address these challenges for a
battery that uses a lithium metal negative electrode. For example,
while some researchers combined liquid electrolytes with
lithium-stuffed garnets, the electrolytes used were insufficiently
dense or of the incorrect form factor to protect a lithium metal
negative electrode from exposure to the volatile components of the
electrolyte. Also, for example, these electrolytes were
insufficiently dense or of the incorrect form factor to protect an
electrochemical cell from lithium dendrite growth. As such, the
components in the liquid electrolyte would not be separated from a
lithium metal negative electrode if one were used with these prior
methods.
[0006] There is therefore a need for improved materials and methods
for bonding electrolyte separators to positive electrodes. What is
needed are, for example, new bonding agents for bonding a solid
separator, e.g., a lithium-stuffed garnet separator, to a positive
electrode in such a way that the bonding agent, the electrolyte or
the catholyte in the positive electrode, do not detrimentally react
with the Li metal in a lithium metal negative electrode but still
provide a conduction medium for Li.sup.+ ions to conduct between
the electrodes. What is also needed in the relevant field is a
material which bonds or adheres, or maintains direct contact
between, a solid separator and a positive electrode and also lowers
the resistance/impedance at the interface therebetween. The instant
disclosure sets forth such materials and methods, in addition to
making and using such materials and methods, and other solutions to
problems in the relevant field.
BRIEF SUMMARY
[0007] In one embodiment, the instant disclosure sets forth an
electrochemical stack which includes a lithium metal (Li) negative
electrode, a positive electrode, an electrolyte separator in direct
contact with the Li metal negative electrode, and a bonding layer
comprising a lithium salt, a polymer, and a solvent. In some
examples, the bonding layer is a gel electrolyte. The bonding layer
directly contacts, and is positioned between, the electrolyte
separator and the positive electrode, and the electrolyte separator
protects the Li metal negative electrode from exposure to the
polymer or to the solvent, or both, in the bonding layer. As
described herein, in some examples, the bonding layer lowers the
interfacial impedance at the interface between the electrolyte
separator and the positive electrode when compared to the
electrolyte separator in direct physical contact with the positive
electrode. In some examples, the bonding layer lowers the
interfacial impedance at the interface between the electrolyte
membrane and the positive electrode by a factor of at least 10, at
least 100, or at least 1000 with respect to the interfacial
impedance at the interface between the electrolyte membrane and the
positive electrode when a bonding layer is not positioned between,
the electrolyte membrane and the positive electrode.
[0008] In a second embodiment, the instant disclosure sets forth a
method of making a free standing gel electrolyte, wherein the
method includes spin coating solution to form a gel electrolyte
onto a solid separator, wherein the solution includes two or more
solvents, wherein the two or more solvents have different boiling
points, and volatilizing at least one of the two or more solvents
to form a porous gel electrolyte on a solid separator.
[0009] In a third embodiment, the instant disclosure sets forth a
method of making an electrochemical stack having a solid
electrolyte separator and a gel electrolyte.
[0010] In a fourth embodiment, the instant disclosure sets forth a
method of using an electrochemical stack having a solid electrolyte
separator and a gel electrolyte.
[0011] In a fifth embodiment, the instant disclosure sets forth a
phase-inversion gel electrolyte on the surface of a solid separator
in contact with a cathode, wherein the gel electrolyte can be cast,
bonded, laminated or adhered to a solid separator through spin
coating, doctor blading, or other related techniques.
[0012] In a sixth embodiment, the instant disclosure sets forth a
method of making a phase-inversion gel electrolyte.
[0013] In a seventh embodiment, the instant disclosure sets forth a
method of making an electrochemical stack having a solid
electrolyte separator and a phase-inversion. In some examples, the
phase inversion gel is spin-coated on the solid electrolyte
separator.
[0014] In an eighth embodiment, the instant disclosure sets forth a
method of using an electrochemical stack having a solid separator
and a phase-inversion gel spin-coated on the electrochemical
stack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a side view of an example electrochemical
stack, 100, with comparison to another example electrochemical
stack, 101.
[0016] FIG. 2 shows the electrochemical performance of an
electrochemical stack as set forth in the electrochemical stack,
100, with comparison to an electrochemical stack as set forth in
the electrochemical stack, 101. FIG. 2 is a plot of Voltage [V] as
a function of Run time [s].
[0017] FIG. 3 shows a charge-discharge Galvanostatic Intermittent
Titration Technique (GITT) plot for an electrochemical stack as set
forth in the electrochemical stack, 101. FIG. 3 is a plot of
Voltage [V] as a function of Cycle active mass-specific capacity
[maAh/g].
[0018] FIG. 4 shows a scanning electron microscopy cross-sectional
image of a thin (.about.0.3 .mu.m) PVDF containing gel electrolyte,
401, on a glass slide, 402. Scale bar is 5 .mu.m.
[0019] FIG. 5 shows a scanning electron microscopy cross-sectional
image of a 47.4% polyacrylonitrile (PAN) gel electrolyte spin-cast
onto a garnet separator wherein the PAN gel is spin-cast at 2000
RPM. Scale bar is 100 .mu.m.
[0020] FIG. 6 shows a side view of an example electrochemical test
step-up.
[0021] FIG. 7 shows a side view of an example electrochemical test
step-up for determining the Area Specific Resistance (ASR) of the
gel bonding layer with the garnet electrolyte.
[0022] FIG. 8 shows a summary of interfacial ASR for various gel
electrolytes as a function of the spin-casting RPM used to prepare
the gel electrolyte in an electrochemical cell and as set forth in
the electrochemical test step-up in FIG. 7.
[0023] FIG. 9 shows a plot of interfacial impedance
(.OMEGA.cm.sup.2) as a function of type of electrolyte material
(liquid, gel, polymer, and solid) at 45.degree. C.
[0024] FIG. 10 shows a plain view of the phase inversion
spin-coated gel, showing porous morphology on a cross-sectional
thickness of one micron. The scale bar is 10 .mu.m.
[0025] FIG. 11 shows a cross-section (left-side scanning electron
microscope images (SEM) of the phase inversion spin-coated gel,
showing porous morphology on a cross-sectional thickness of one
micron. The scale bar is 5 .mu.m.
[0026] FIG. 12 shows a focused ion beam (FIB) scanning electron
microscopy cross-sectional image of a full cell cross section with
a cathode in contact with PVDF-HFP phase inversion spin coated gel
electrolyte onto a garnet separator where in the gel is spin-coated
at 1200 RPM. Scale bar is 10 .mu.m.
[0027] FIG. 13 shows Electrochemical Impedance Spectrum (EIS) of
the phase-inversion spin coated gel sandwiched between two oxide
separator pellets in a symmetric cell.
[0028] FIG. 14 shows the results of a contact angle measurement
from Example 5.
[0029] The figures depict various embodiments of the present
disclosure for purposes of illustration only. One skilled in the
art will readily recognize from the following discussion that
alternative embodiments of the structures and methods illustrated
herein may be employed without departing from the principles
described herein.
DETAILED DESCRIPTION
[0030] The following description is presented to enable one of
ordinary skill in the art to make and use the invention and to
incorporate it in the context of particular applications. Various
modifications, as well as a variety of uses in different
applications will be readily apparent to those skilled in the art,
and the general principles defined herein may be applied to a wide
range of embodiments. Thus, the inventions herein are not intended
to be limited to the embodiments presented, but are to be accorded
their widest scope consistent with the principles and novel
features disclosed herein.
[0031] All the features disclosed in this specification, (including
any accompanying claims, abstract, and drawings) may be replaced by
alternative features serving the same, equivalent or similar
purpose, unless expressly stated otherwise. Thus, unless expressly
stated otherwise, each feature disclosed is one example only of a
generic series of equivalent or similar features.
[0032] Please note, if used, the labels left, right, front, back,
top, bottom, forward, reverse, clockwise and counter clockwise have
been used for convenience purposes only and are not intended to
imply any particular fixed direction. Instead, they are used to
reflect relative locations and/or directions between various
portions of an object.
General Description
I. Introduction
[0033] Set forth herein are electrochemical cells which include a
negative electrode current collector, a lithium metal negative
electrode, a solid electrolyte membrane (e.g., an electrolyte
separator comprising a lithium-stuffed garnet oxide), a bonding
agent layer, a positive electrode, and a positive electrode current
collector. As used herein, a membrane is a type of separator. In
these cells, the lithium metal negative electrode directly contacts
and is positioned between the negative electrode current collector
and the electrolyte membrane; the electrolyte directly contacts and
is positioned between the lithium metal negative electrode and the
bonding agent layer; the bonding agent layer directly contacts and
is positioned between the electrolyte and the positive electrode;
and the positive electrode directly contacts and is positioned
between the bonding agent layer and the positive electrode current
collector. The bonding agent layer advantageously lowers the
interfacial impedance of the oxide-based electrolyte at the
positive electrode interface and also assists in the adhesion of
the electrolyte to a positive electrode interface. The bonding
layer, in some examples, is stable at high voltages (e.g., stable
against chemical reaction above 4.0 V, 4.1 V, 4.2 V, 4.3 V, 4.4 V,
4.5 V, or 4.6 V). Also set forth herein are electrochemical cell
configurations wherein the bonding layer is physically separated
from the lithium metal negative electrode by an oxide such as, but
not limited to, a lithium-stuffed garnet, a lithium aluminum
titanium phosphate, or a lithium germanium titanium phosphate. In
some examples, these oxides are sintered, dense, pinhole,
defect-free, or combinations thereof such that neither the solvent
nor polymer included in the bonding agent layer directly contacts
the lithium metal negative electrode. Also set forth herein are
methods of making these bonding agent layers including, but not
limited to, methods of preparing and depositing precursor solutions
which form these bonding agent layers. Set forth herein,
additionally, are methods of using these electrochemical cells.
Also, set forth herein are free standing layers of a gel
electrolyte which can be included in an electrochemical device or
stack described herein as a bonding layer. Also, set forth, herein,
is a phase-inversion gel electrolyte which is spin-coated, or
otherwise coated to, laminated on, or in contact with the surface
of the solid separator which can be included in an electrochemical
device or stack.
II. Definitions
[0034] As used herein, the term "about," when qualifying a number,
e.g., 15% w/w, refers to the number qualified and optionally the
numbers included in a range about that qualified number that
includes .+-.10% of the number. For example, about 15% w/w includes
15% w/w as well as 13.5% w/w, 14% w/w, 14.5% w/w, 15.5% w/w, 16%
w/w, or 16.5% w/w. For example, "about 75.degree. C.," includes
75.degree. C. as well 68.degree. C., 69.degree. C., 70.degree. C.,
71.degree. C., 72.degree. C., 73.degree. C., 74.degree. C.,
75.degree. C., 76.degree. C., 77.degree. C., 78.degree. C.,
79.degree. C., 80.degree. C., 81.degree. C., 82.degree. C., or
83.degree. C.
[0035] As used herein, the term, "Ra," is a measure of surface
roughness wherein Ra is an arithmetic average of absolute values of
sampled surface roughness amplitudes. Surface roughness
measurements can be accomplished using, for example, a Keyence
VK-X100 instrument that measures surface roughness using a laser.
As used herein, the term, "Rt," is a measure of surface roughness
wherein Rt is the maximum peak height of sampled surface roughness
amplitudes. Disclosed herein are methods of modifying the surface
roughness of an electrolyte, which methods include polishing,
ablating, exposing to laser, exposing to plasma, exposing to ozone,
exposing to a reducing atmosphere at elevate temperatures such as
but not limited to 400.degree. C., 500.degree. C., 600.degree. C.,
700.degree. C., 800.degree. C., 900.degree. C., 1000.degree. C.,
1100.degree. C., 1200.degree. C., 1300.degree. C., or higher, or
annealing the surface in order to achieve the desired surface
roughness.
[0036] As used herein, "selected from the group consisting of"
refers to a single member from the group, more than one member from
the group, or a combination of members from the group. A member
selected from the group consisting of A, B, and C includes, for
example, A only, B only, or C only, as well as A and B, A and C, B
and C, as well as A, B, and C.
[0037] As used herein, the phrases "electrochemical cell" or
"battery cell" shall mean a single cell including a positive
electrode and a negative electrode, which have ionic communication
between the two using an electrolyte. In some embodiments, the same
battery cell includes multiple positive electrodes and/or multiple
negative electrodes enclosed in one container.
[0038] As used herein the phrase "electrochemical stack," refers to
one or more units which each include at least a negative electrode
(e.g., Li, LiC.sub.6), a positive electrode (e.g.,
Li-nickel-manganese-oxide or FeF.sub.3, optionally a gel
electrolyte), and a solid electrolyte (e.g., an electrolyte set
forth herein). In some examples, between the solid electrolyte and
the positive electrode, there is an additional layer comprising a
gel electrolyte. An electrochemical stack may include one of these
aforementioned units. An electrochemical stack may include several
of these aforementioned units arranged in electrical communication
(e.g., serial or parallel electrical connection). In some examples,
when the electrochemical stack includes several units, the units
are layered or laminated together in a column. In some examples,
when the electrochemical stack includes several units, the units
are layered or laminated together in an array. In some examples,
when the electrochemical stack includes several units, the stacks
are arranged such that one negative electrode is shared with two or
more positive electrodes. Alternatively, in some examples, when the
electrochemical stack includes several units, the stacks are
arranged such that one positive electrode is shared with two or
more negative electrodes. Unless specified otherwise, an
electrochemical stack includes one positive electrolyte between the
positive electrode and the solid electrolyte.
[0039] As used herein, the phrases "gel electrolyte," unless
specified otherwise, refers to a suitable Li.sup.+ ion conducting
gel or liquid-based electrolyte, for example, those set forth in
U.S. Pat. No. 5,296,318, entitled RECHARGEABLE LITHIUM
INTERCALATION BATTERY WITH HYBRID POLYMERIC ELECTROLYTE, which is
incorporated by reference in its entirety for all purposes. A gel
electrolyte has lithium ion conductivity of greater than
10.sup.-5S/cm at room temperature, a lithium transference number
between 0.05-0.95, and a storage modulus greater than the loss
modulus at some temperature. A gel may comprise a polymer matrix, a
solvent that gels the polymer, and a lithium containing salt that
is at least partly dissociated into Li.sup.+ ions and anions.
Herein, in some examples, the gel electrolyte is used as the
bonding layer.
[0040] As used herein, the phrase "one stage gel electrolyte,"
refers to an electrolyte made using a single precursor solution
which already includes an electrolyte solution and lithium salt and
which is cast and allowed to evaporate the higher boiling point
solvents.
[0041] As used herein, the phrase "two stage gel electrolyte,"
refers to an electrolyte made using a precursor solution which
includes a polymer and a plasticizer. After casting this solution,
in a first stage, the plasticizer is either leached out, using a
solvent in second stage, or dried; the resulting porosity is
refilled by soaking it in an electrolyte solution.
[0042] As used herein, the phrase "phase-inversion gel
electrolyte", unless specified otherwise, refers to a suitable
Li.sup.+ion conducting gel formed by a controlled polymer
transformation from a liquid phase to solid phase. The phase
inversion gel electrolyte includes a polymer with a solvent, and a
second solvent which does not solvate the polymer, and a lithium
salt, wherein the concentration of the polymer is 2-10% by volume,
wherein the concentration of the lithium salt is 8-12% by volume,
and where the composition includes at least 20-40% by porosity by
volume. To make a phase-inversion gel electrolyte, the polymer in
this case is dissolved in a solvent and non-solvent mixture. A
lithium salt is then added. The evaporation of the solvent due to
high volatility occurs or is induced, causing the composition to
have a higher non-solvent concentration in the mixture. The polymer
precipitates and forms a porous membrane, resulting in a
phase-inversion gel electrolyte which includes the lithium
salt.
[0043] As used herein, the phrase "spin-coated" or "spin-casted"
refers to a process used to deposit a uniform thin film on a
substrate. This can be accomplished by applying a small amount of
viscous coating material to the substrate. The substrate is rotated
during or after the application of the coating material to form a
relatively uniform coating thickness.
[0044] As used herein, the phrase "non-solvent" refers to a liquid
in which the polymer has little to no solubility. In some examples,
the non-solvent is toluene when the polymer is PVDF-HFP. In other
examples, the non-solvent is dibutyl phthalate (DBP), glycerol, or
carbonate electrolyte solvents such as ethylene carbonate when the
polymer is PVDF-HFP.
[0045] As used herein, the phrase "solvent" refers, unless
specified otherwise, to a solvent which dissolves the polymer used
in the gel electrolyte or phase inversion gel. In some examples,
the solvent is tetrahydrofuran when the polymer is PVDF-HFP. In
other examples, the solvent is dimethylformamide (DMF) or
N-methyl-pyrrolidone (e.g., N-methyl-2-pyrrolidone or NMP) when the
polymer is PVDF-HFP.
[0046] As used herein, the terms "cathode" and "anode" refer to the
electrodes of a battery. During a charge cycle in a Li-secondary
battery, Li ions leave the cathode and move through an electrolyte,
to the anode. During a charge cycle, electrons leave the cathode
and move through an external circuit to the anode. During a
discharge cycle in a Li-secondary battery, Li ions migrate towards
the cathode through an electrolyte and from the anode. During a
discharge cycle, electrons leave the anode and move through an
external circuit to the cathode. Unless otherwise specified, the
cathode refers to the positive electrode. Unless otherwise
specified, the anode refers to the negative electrode.
[0047] As used herein, the term "catholyte," refers to a Li ion
conductor that is intimately mixed with, or that surrounds, or that
contacts the positive electrode active materials and provides an
ionic pathway for Li.sup.+ to and from the active materials.
Catholytes suitable with the embodiments described herein include,
but are not limited to, catholytes having the common name
Li-stuffed garnets, LPS, LXPS, LATS, or LXPSO, where X is Si, Ge,
Sn, As, Al, or also combinations thereof, and the like. Catholytes
may also be liquid, gel, semi-liquid, semi-solid, polymer, and/or
solid polymer ion conductors known in the art or described herein.
Catholytes include those catholytes set forth in US Patent
Application Publication No. 2015-0171465, which published on Jun.
18, 2015, entitled SOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY
USING Li.sub.AMP.sub.BS.sub.C (M.dbd.Si, Ge, AND/OR Sn), filed May
15, 2014, and which is now U.S. Pat. No. 9,172,114, the contents of
which are incorporated by reference in their entirety. Catholytes
are also found in U.S. Pat. Nos. 9,553,332 and 9,634,354, the
contents of which are incorporated by reference in their entirety.
Catholytes include those catholytes set forth in US Patent
Application Publication No. 2015/0099190, published on Apr. 9,
2015, entitled GARNET MATERIALS FOR LI SECONDARY BATTERIES AND
METHODS OF MAKING AND USING GARNET MATERIALS, and filed Oct. 7,
2014, the contents of which are incorporated by reference in their
entirety. In some examples, the gel electrolyte (e.g.,) referred to
herein is an 80:20 to 50:50 vol. % PVDF-HFP to EC: EMC. Herein,
PVDF is polyvinylidene fluoride; HFP is hexafluorophosphate; EC is
ethylene carbonate; and EMC is ethyl methyl carbonate.
[0048] As used herein, the term "electrolyte," refers to a material
that allows ions, e.g., Li.sup.+, to migrate therethrough but which
does not allow electrons to conduct therethrough. Electrolytes are
useful for electrically isolating the cathode and anodes of a
rechargeable (i.e., secondary) battery while allowing ions, e.g.,
Li.sup.+, to transmit through the electrolyte.
[0049] As used herein, the phrase "d.sub.50 diameter" or "median
diameter (d.sub.50)" refers to the median size, in a distribution
of sizes, measured by microscopy techniques or other particle size
analysis techniques, such as, but not limited to, scanning electron
microscopy or dynamic light scattering. D.sub.50 describes a
characteristic dimension of particles at which 50% of the particles
are smaller than the recited size. As used herein "diameter
(d.sub.90)" refers to the size, in a distribution of sizes,
measured by microscopy techniques or other particle size analysis
techniques, including, but not limited to, scanning electron
microscopy or dynamic light scattering. D.sub.90 includes the
characteristic dimension at which 90% of the particles are smaller
than the recited size. As used herein "diameter (d.sub.10)" refers
to the size, in a distribution of sizes, measured by microscopy
techniques or other particle size analysis techniques, including,
but not limited to, scanning electron microscopy or dynamic light
scattering. Dio includes the characteristic dimension at which 10%
of the particles are smaller than the recited size.
[0050] As used herein, the term "rational number" refers to any
number which can be expressed as the quotient or fraction (e.g.,
p/q) of two integers (e.g., p and q), with the denominator (e.g.,
q) not equal to zero. Example rational numbers include, but are not
limited to, 1, 1.1, 1.52, 2, 2.5, 3, 3.12, and 7.
[0051] As used herein, the phrase "subscripts and molar
coefficients in the empirical formulas are based on the quantities
of raw materials initially batched to make the described examples"
means the subscripts, (e.g., 7, 3, 2, 12 in
Li.sub.7La.sub.3Zr.sub.2O.sub.12 and the coefficient 0.35 in
0.35Al.sub.2O.sub.3) refer to the respective elemental ratios in
the chemical precursors (e.g., LiOH, La.sub.2O.sub.3, ZrO.sub.2,
Al.sub.2O.sub.3) used to prepare a given material, (e.g.,
Li.sub.7La.sub.3Zr.sub.2O.sub.12.0.35Al.sub.2O.sub.3).
[0052] As used herein, a "thickness" by which is film is
characterized refers to the distance, or median measured distance,
between the top and bottom faces of a film. As used herein, the top
and bottom faces refer to the sides of the film having the largest
surface area.
[0053] As used herein, the phrase "density as determined by
geometric measurements," refers to measurements of density obtained
by physical mass and volume measurements. Density is determined by
the ratio of measured mass to the measured volume. Customary
techniques including the Archimedes method may be employed for such
determinations. Unless stated otherwise, the density as determined
by geometric measurements is the Archimedes method.
[0054] As used herein, the phrase "density as measured by the
Archimedes method," refers to a density inclusive of closed
porosity but exclusive of open porosity. The dimensions of a dry
part are measured and the volume is calculated and recorded as Va.;
the mass of the dry part is measured and recorded as ma. Vacuum
infiltration of the part with a solvent such as toluene or IPA is
then conducted by, for example, pulling a vacuum on the parts for
at least one hour to a pressure less than -20 inHg and then
submerge the parts in solvent, infiltrate for at least 30 minutes.
Next, the vacuum is released, keeping parts submerged in solvent.
Then, the surface liquid is wiped off of the part, and record the
mass mw of the part when wet. Finally, recording the mass ms of the
part when submerged in the cup is performed. The Archimedes bulk
density is calculated as m.sub.d/(m.sub.w-m.sub.s).rho..sub.s,
where .rho..sub.s is the solvent density, and the open porosity is
(m.sub.w-m.sub.d)/(m.sub.w-m.sub.s).
[0055] As used herein, the phrase "density as determined by
scanning electron microscopy (SEM)," refers to the analysis of
scanning electron microscopy (SEM) images. This analysis includes
measuring the relative amounts of the electrolyte separator which
are porous or vacant with respect to the electrolyte separator
which is fully dense. The SEM images useful for this analysis
include those obtained by SEM cross-sectional analysis using
focused ion beam (FIB) milling.
[0056] As used herein, the phrase "porosity as determined by SEM,"
refers to measurement of density by using an image analysis
software. First, a user or software assigns pixels and/or regions
of an image as porosity. Second, the area fraction of those regions
is summed. Finally, the porosity fraction determined by SEM is
equal to the area fraction of the porous region of the image.
Herein, porosity by volume is determined by SEM as set forth in
this paragraph unless stated otherwise to the contrary.
[0057] As used herein, the term "laminating" refers to the process
of sequentially depositing a layer of one precursor species, e.g.,
a lithium precursor species, onto a deposition substrate and then
subsequently depositing an additional layer onto an already
deposited layer using a second precursor species, e.g., a
transition metal precursor species. This laminating process can be
repeated to build up several layers of deposited vapor, liquid, or
semi-solid phases. As used herein, the term "laminating" also
refers to the process whereby a layer comprising an electrode,
e.g., positive electrode or cathode active material comprising
layer, is contacted to a layer comprising another material, e.g.,
garnet electrolyte. The laminating process may include a reaction
or use of a binder which adheres of physically maintains direct
contact between the layers which are laminated.
[0058] As used herein, the term "electrolyte," refers to an
ionically conductive and electrically insulating material.
Electrolytes are useful for electrically insulating the positive
and negative electrodes of a secondary battery while allowing for
the conduction of ions, e.g., Li.sup.+, through the electrolyte. In
some of the electrochemical devices described herein, the
electrolyte includes a solid film, pellet, or monolith of a
Li.sup.+ conducting oxide, such as a lithium-stuffed garnet. In
some examples, the electrolyte further includes a gel electrolyte
which is laminated to or directly contacting the solid film,
pellet, or monolith.
[0059] As used herein, the phrase "antiperovskite" refers to the
family of materials with an antiperovskite crystal structure and
the composition Li.sub.aO.sub.bX.sub.cH.sub.dM.sub.e where X is
selected from Cl, Br, I, and F and mixtures thereof, and M is
selected from Al, Ge, and Ga. In the formula
Li.sub.aO.sub.bX.sub.cH.sub.dM.sub.e, the subscripts are chosen
such that 2<a<4, 0.7<b<1.3, 0.7<c<1.3,
0.ltoreq.d<1, 0.ltoreq.e<1.
[0060] As used herein, the phrase "lithium stuffed garnet" refers
to oxides that are characterized by a crystal structure related to
a garnet crystal structure. Electrolytes include those electrolytes
set forth in US Patent Application Publication No. 2015-0171465,
which published on Jun. 18, 2015, entitled SOLID STATE CATHOLYTE OR
ELECTROLYTE FOR BATTERY USING Li.sub.AMP.sub.BS.sub.C (M.dbd.Si,
Ge, AND/OR Sn), filed May 15, 2014, and which is now U.S. Pat. No.
9,172,114, the contents of which are incorporated by reference in
their entirety. Electrolytes are also found in U.S. Pat. Nos.
9,553,332 and 9,634,354, the contents of which are incorporated by
reference in their entirety. Electrolytes include those
electrolytes set forth in US Patent Application Publication No.
2015/0099190, published on Apr. 9, 2015, entitled GARNET MATERIALS
FOR LI SECONDARY BATTERIES AND METHODS OF MAKING AND USING GARNET
MATERIALS, and filed Oct. 7, 2014, the contents of which are
incorporated by reference in their entirety. This application
describes Li-stuffed garnet solid-state electrolytes used in
solid-state lithium rechargeable batteries. These Li-stuffed
garnets generally having a composition according to
Li.sub.ALa.sub.BM'.sub.CM''.sub.DZr.sub.EO.sub.F,
Li.sub.ALa.sub.BM'.sub.CM''.sub.DTa.sub.EO.sub.F, or
Li.sub.ALa.sub.BM'.sub.CM''.sub.DNb.sub.EO.sub.F, wherein
4<A<8.5, 1.5<B<4, 0.ltoreq.C.ltoreq.2,
0.ltoreq.D.ltoreq.2; 0.ltoreq.E<2.3, 10<F<13, and M' and
M'' are each, independently in each instance selected from Al, Mo,
W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, or Ta, or
Li.sub.aLa.sub.bZr.sub.cAl.sub.dMe''.sub.eO.sub.f, wherein
5<a<8.5; 2<b<4; 0<c.ltoreq.2.5; 0.ltoreq.d<2;
0.ltoreq.e<2, and 10<f<13 and Me'' is a metal selected
from Nb, Ta, V, W, Mo, or Sb and as otherwise described in U.S.
Patent Application Publication No. U.S. 2015/0099190. In some
examples, A may be about 6.0 or about 6.1 or about 6.2 or about 6.3
or about 6.4 or about 6.5 or about 6.6 or about 6.7 or about 6.8 or
about 6.9 or about 7.0 or about 7.1 or about 7.2 or about 7.3 or
about 7.4. In some examples, B may be about 2.8 or about 2.9 or
about 3.0 or about 3.1 or about 3.2. In some examples, C may be
about 0 or about 0.1 or about 0.2 or about 0.3 or about 0.4 or
about 0.5 or about 0.6 or about 0.7 or about 0.8 or about 0.9 or
about 1.0 or about 1.1 or about 1.2 or about 1.3 or about 1.4 or
about 1.5 or about 1.6 or about 1.7 or about 1.8 or about 1.9 or
about 2.0. In some examples D may be about 0 or about 0.1 or about
0.2 or about 0.3 or about 0.4 or about 0.5 or about 0.6 or about
0.7 or about 0.8 or about 0.9 or about 1.0 or about 1.1 or about
1.2 or about 1.3 or about 1.4 or about 1.5 or about 1.6 or about
1.7 or about 1.8 or about 1.9 or about 2.0. In some examples, E may
be about 1.4 or about 1.5 or about 1.6 or about 1.7 or about 1.8 or
about 1.9 or about 2.0 or about 2.1 or about 2.2. In some examples,
F may be about 11.0 or about 11.1 or about 11.2 or about 11.3 or
about 11.4 or about 11.5 or about 11.6 or about 11.7 or about 11.8
or about 11.9 or about 12.0 or about 12.1 or about 12.2 or about
12.3 or about 12.4 or about 12.5 or about 12.6 or about 12.7 or
about 12.8 or about 12.9 or about 13.0. Herein, the subscript
values and coefficient values are selected so the compound is
charge neutral unless stated otherwise to the contrary. As used
herein, lithium-stuffed garnets, and garnets, generally, include,
but are not limited to,
Li.sub.7.0La.sub.3(Ar.sub.t1+Nb.sub.t2+Ta.sub.t3)O.sub.12+0.35Al.sub.2O.s-
ub.3; wherein (subscripts t1+t2+t3=subscript 2) so that the
La:(Zr/Nb/Ta) ratio is 3:2. Also, garnets used herein include, but
are not limited to,
Li.sub.xLa.sub.3Zr.sub.2O.sub.F+yAl.sub.2O.sub.3, wherein x ranges
from 5.5 to 9; and y ranges from 0 to 1. In these examples,
subscripts x, y, and F are selected so that the garnet is charge
neutral. In some examples x is 7 and y is 1.0. In some examples, x
is 5 and y is 1.0. In some examples, x is 6 and y is 1.0. In some
examples, x is 8 and y is 1.0. In some examples, x is 9 and y is
1.0. In some examples x is 7 and y is 0.35. In some examples, x is
5 and y is 0.35. In some examples, x is 6 and y is 0.35. In some
examples, x is 8 and y is 0.35. In some examples, x is 9 and y is
0.35. In some examples x is 7 and y is 0.7. In some examples, x is
5 and y is 0.7. In some examples, x is 6 and y is 0.7. In some
examples, x is 8 and y is 0.7. In some examples, x is 9 and y is
0.7. In some examples x is 7 and y is 0.75. In some examples, x is
5 and y is 0.75. In some examples, x is 6 and y is 0.75. In some
examples, x is 8 and y is 0.75. In some examples, x is 9 and y is
0.75. In some examples x is 7 and y is 0.8. In some examples, x is
5 and y is 0.8. In some examples, x is 6 and y is 0.8. In some
examples, x is 8 and y is 0.8. In some examples, x is 9 and y is
0.8. In some examples x is 7 and y is 0.5. In some examples, x is 5
and y is 0.5. In some examples, x is 6 and y is 0.5. In some
examples, x is 8 and y is 0.5. In some examples, x is 9 and y is
0.5. In some examples x is 7 and y is 0.4. In some examples, x is 5
and y is 0.4. In some examples, x is 6 and y is 0.4. In some
examples, x is 8 and y is 0.4. In some examples, x is 9 and y is
0.4. In some examples x is 7 and y is 0.3. In some examples, x is 5
and y is 0.3. In some examples, x is 6 and y is 0.3. In some
examples, x is 8 and y is 0.3. In some examples, x is 9 and y is
0.3. In some examples x is 7 and y is 0.22. In some examples, x is
5 and y is 0.22. In some examples, x is 6 and y is 0.22. In some
examples, x is 8 and y is 0.22. In some examples, x is 9 and y is
0.22. Also, garnets as used herein include, but are not limited to,
Li.sub.xLa.sub.3Zr.sub.2O.sub.12+yAl.sub.2O.sub.3. In one
embodiment, the Li-stuffed garnet herein has a composition of
Li.sub.7Li.sub.3Zr.sub.2O.sub.12. In another embodiment, the
Li-stuffed garnet herein has a composition of
Li.sub.7Li.sub.3Zr.sub.2O.sub.12.Al.sub.2O.sub.3. In yet another
embodiment, the Li-stuffed garnet herein has a composition of
Li.sub.7Li.sub.3Zr.sub.2O.sub.12.0.22Al.sub.2O.sub.3. In yet
another embodiment, the Li-stuffed garnet herein has a composition
of Li.sub.7Li.sub.3Zr.sub.2O.sub.12.0.35Al.sub.2O.sub.3. In certain
other embodiments, the Li-stuffed garnet herein has a composition
of Li.sub.7Li.sub.3Zr.sub.2O.sub.12.0.5Al.sub.2O.sub.3. In another
embodiment, the Li-stuffed garnet herein has a composition of
Li.sub.7Li.sub.3Zr.sub.2O.sub.12.0.75Al.sub.2O.sub.3.
[0061] As used herein, garnet does not include YAG-garnets (i.e.,
yttrium aluminum garnets, or, e.g., Y.sub.3A.sub.15O.sub.12). As
used herein, garnet does not include silicate-based garnets such as
pyrope, almandine, spessartine, grossular, hessonite, or
cinnamon-stone, tsavorite, uvarovite and andradite and the solid
solutions pyrope-almandine-spessarite and
uvarovite-grossular-andradite. Garnets herein do not include
nesosilicates having the general formula
X.sub.3Y.sub.2(SiO.sub.4).sub.3 wherein X is Ca, Mg, Fe, and, or,
Mn; and Y is Al, Fe, and, or, Cr.
[0062] As used herein, the phrases "garnet precursor chemicals,"
"chemical precursor to a garnet-type electrolyte," "precursors to
garnet" and "garnet precursor materials" refer to chemicals which
react to form a lithium stuffed garnet material described herein.
These chemical precursors include, but are not limited to lithium
hydroxide (e.g., LiOH), lithium oxide (e.g., Li.sub.2O), lithium
carbonate (e.g., LiCO.sub.3), zirconium oxide (e.g., ZrO.sub.2),
zirconium hydroxide, zirconium acetate, zirconium nitrate,
zirconium acetylacetonate, zirconium nitrate x-hydrate, lanthanum
oxide (e.g., La.sub.2O.sub.3), lanthanum hydroxide (e.g.,
La(OH).sub.3), lanthanum nitrate, lanthanum acetate, lanthanum
acetylacetonate, aluminum oxide (e.g., Al.sub.2O.sub.3), aluminum
hydroxide (e.g., Al(OH).sub.3), aluminum (e.g., Al), aluminum
nitrate (e.g., Al(NO.sub.3).sub.3), aluminum nitrate nonahydrate,
boehmite, gibbsite, corundum, aluminum oxyhydroxide, niobium oxide
(e.g., Nb.sub.2O.sub.5), gallium oxide (Ga.sub.2O.sub.3), and
tantalum oxide (e.g., Ta.sub.2O.sub.5). Other precursors to garnet
materials, known in the relevant field to which the instant
disclosure relates, may be suitable for use with the methods set
forth herein.
[0063] As used herein the phrase "garnet-type electrolyte," refers
to an electrolyte that includes a lithium stuffed garnet material
described herein as the Li.sup.+ ion conductor.
[0064] As used herein, the phrase "doped with alumina" means that
Al.sub.2O.sub.3 is used to replace certain components of another
material, e.g., a garnet. A lithium stuffed garnet that is doped
with Al.sub.2O.sub.3 refers to garnet wherein aluminum (Al)
substitutes for an element in the lithium stuffed garnet chemical
formula, which may be, for example, Li or Zr.
[0065] As used herein, the phrase "reaction vessel" refers to a
container or receptacle into which precursor chemicals are placed
in order to conduct a chemical reaction to produce a product, e.g.,
a lithium stuffed garnet material.
[0066] As used herein, the term "defect" refers to an imperfection
or a deviation from a pristine structure such as, but not limited
to, a pore, a crack, a separation, a chemical inhomogeneity, or a
phase segregation of two or more materials in a solid material. A
perfect crystal is an example of a material that lacks defects. A
nearly 100% dense electrolyte that has a planar surface, with
substantially no pitting, cracks, pores, or divots on the surface,
is an example of an electrolyte that is substantially lacking
defects. A surface of an electrolyte is substantially lacking
defects if the defect density is less than 1 defect per 1 mm.sup.2.
An electrolyte's bulk is substantially lacking defects if the
defect density is less than 1 defect per 1 mm.sup.3.
[0067] As used herein the term "porous," refers to a material that
includes pores, e.g., nanopores, mesopores, or micropores.
[0068] As used herein, "flatness" of a surface refers to the
greatest normal distance between the lowest point on a surface and
a plane containing the three highest points on the surface, or
alternately, the greatest normal distance between the highest point
on a surface and a plane containing the three lowest points on the
surface. It may be measured with an AFM, a high precision optical
microscope, or laser interferometry height mapping of a
surface.
[0069] As used herein the phrase "free standing thin film," refers
to a film that is not adhered or supported by an underlying
substrate. In some examples, free standing thin film is a film that
is self-supporting, which can be mechanically manipulated or moved
without need of substrate adhered or fixed thereto. A free standing
thin film can be laminated or bonded to a current collector or
electrode, but such a free standing thin film is only free standing
when not supported by an underlying substrate.
[0070] As used here, the phrase "inorganic solid state
electrolyte," refers to a material not including carbon which
conducts ions (e.g., Li.sup.+) but does not conduct electrons.
Example inorganic solid state electrolytes include oxide
electrolytes and sulfide electrolytes, which are further described
in the instant disclosure.
[0071] As used here, the phrase "directly contacts," refers to the
juxtaposition of two materials such that the two materials contact
each other sufficiently to conduct either an ion or electron
current. As used herein, direct contact may also refer to two
materials in contact with each other and which do not have any
other different types of solid or liquid materials positioned
between the two materials which are in direct contact.
[0072] As used here, the phrase "composite separator" or "composite
electrolyte" refer to a composite of a polymer and a solid ion
conductor. The solid ion conductor may include any of the ion
conductors mentioned herein. The polymer may be an epoxy, a rubber,
or any composition mentioned in US Patent Application Publication
No. 2017-0005367 A1, entitled COMPOSITE ELECTROLYTES, which was
filed as U.S. patent application Ser. No. 15/192,960, filed Jun.
24, 2016, on 16 which is incorporated herein by reference in its
entirety for all purposes. Examples composite separators may be
found in US Patent Application Publication No. 2017-0005367 A1,
entitled COMPOSITE ELECTROLYTES, which was filed as U.S. patent
application Ser. No. 15/192,960, filed Jun. 24, 2016. In some
examples, the electrolytes herein may include, or be layered with,
or be laminated to, or contact a sulfide electrolyte. As used here,
the phrase "sulfide electrolyte," includes, but is not limited to,
electrolytes referred to herein as LATS, LSS, LTS, LXPS, or LXPSO,
where X is Si, Ge, Sn, As, Al. In these acronyms (LSS, LTS, LXPS,
or LXPSO), S refers to the element S, Si, or combinations thereof,
and T refers to the element Sn. "Sulfide electrolyte" may also
include Li.sub.aP.sub.bS.sub.cX.sub.d,
Li.sub.aB.sub.bS.sub.cX.sub.d, Li.sub.aSn.sub.bS.sub.cor
Li.sub.aSi.sub.bS.sub.cX.sub.d where X.dbd.F, Cl, Br, I, and
10%.ltoreq.a.ltoreq.50%, 10%.ltoreq.b.ltoreq.44%,
24%.ltoreq.c.ltoreq.70%, 0.ltoreq.d.ltoreq.18%. Sulfide
electrolytes may contain less than 5% or less than 10% oxygen.
[0073] In some examples, the sulfide electrolyte layer is a
material containing Si, Li, O, P, and S and is referred to herein
as a SLOPS material. In some examples, the electrolyte layer is a
material containing Si, Li, O, P, and S and is referred to herein
as a SLOPS/LSS material. As used herein, LSS includes, unless
otherwise specified, a 60:40 molar ratio Li.sub.2S:SiS.sub.2.
[0074] As used herein, "SLOPS" includes, unless otherwise
specified, a 60:40 molar ratio of Li.sub.2S:SiS.sub.2 with 0.1-10
mol. % Li.sub.3PO.sub.4. In some examples, "SLOPS" includes
Li.sub.10Si.sub.4S.sub.13 (50:50 Li.sub.2S:SiS.sub.2) with 0.1-10
mol. % Li.sub.3PO.sub.4. In some examples, "SLOPS" includes
Li.sub.26Si.sub.7S.sub.27 (65:35 Li.sub.2S:SiS.sub.2) with 0.1-10
mol. % Li3PO.sub.4. In some examples, "SLOPS" includes
Li.sub.4SiS.sub.4 (67:33 Li.sub.2S:SiS.sub.2) with 0.1-5 mol. %
Li3PO.sub.4. In some examples, "SLOPS" includes
Li.sub.14Si.sub.3S.sub.13 (70:30 Li.sub.2S:SiS.sub.2) with 0.1-5
mol. % Li3PO.sub.4. In some examples, "SLOPS" is characterized by
the formula (1-x)(60:40 Li.sub.2S:SiS.sub.2)*(x)(Li.sub.3PO.sub.4),
wherein x is from 0.01 to 0.99. As used herein, "LBS-PDX" refers to
an electrolyte composition of
Li.sub.2S:B.sub.2S.sub.3:Li.sub.3PO.sub.4:LiX where X is a halogen
(X.dbd.F, Cl, Br, I). The composition can include Li3BS.sub.3 or
Li.sub.5B.sub.7S.sub.13 doped with 0-30% lithium halide such as LiI
and/or 0-10% Li.sub.3PO.sub.4.
[0075] As used here, "LSS" refers to lithium silicon sulfide which
can be described as Li.sub.2S--SiS.sub.2, Li--SiS.sub.2, Li--S--Si,
and/or a catholyte consisting essentially of Li, S, and Si. LSS
refers to an electrolyte material characterized by the formula
Li.sub.xSi.sub.yS.sub.z where 0.33.ltoreq.x.ltoreq.0.5,
0.1.ltoreq.y.ltoreq.0.2, 0.4.ltoreq.z.ltoreq.0.55, and it may
include up to 10 atomic % oxygen. LSS also refers to an electrolyte
material comprising Li, Si, and S. In some examples, LSS is a
mixture of Li.sub.2S and SiS.sub.2. In some examples, the ratio of
Li.sub.2S:SiS.sub.2 is about 90:10, about 85:15, about 80:20, about
75:25, about 70:30, about 2:1, about 65:35, about 60:40, about
55:45, or about 50:50 molar ratio. LSS may be doped with compounds
such as Li.sub.xPO.sub.y, Li.sub.xBO.sub.y, Li.sub.4SiO.sub.4,
Li.sub.3MO.sub.4, Li.sub.3MO.sub.3, PS.sub.x, and/or lithium
halides such as, but not limited to, LiI, LiCl, LiF, or LiBr,
wherein 0<x.ltoreq.5 and 0<y.ltoreq.5. LSS electrolytes may
contain less than 5% or less than 10% oxygen.
[0076] As used here, "LTS" refers to a lithium tin sulfide compound
which can be described as Li.sub.2S:SnS.sub.2:As.sub.2S.sub.5,
Li.sub.2S--SnS.sub.2, Li.sub.2S--SnS, Li--S--Sn, and/or a catholyte
consisting essentially of Li, S, and Sn. The composition may be
Li.sub.xSn.sub.yS.sub.z where 0.25.ltoreq.x.ltoreq.0.65,
0.05.ltoreq.y.ltoreq.0.2, and 0.25.ltoreq.z.ltoreq.0.65. In some
examples, LTS is a mixture of Li.sub.2S and SnS.sub.2 in the ratio
of about 80:20, about 75:25, about 70:30, about 2:1, or about 1:1
molar ratio. LTS may include up to 10 atomic % oxygen. LTS may be
doped with Bi, Sb, As, P, B, Al, Ge, Ga, and/or In and/or lithium
halides such as, but not limited to, LiI, LiCl, LiF, or LiBr, As
used herein, "LATS" refers to LTS, as used above, and further
comprising Arsenic (As). LTS and LATS electrolytes may contain less
than 5% or less than 10% oxygen.
[0077] As used here, "LXPS" refers to a material characterized by
the formula Li.sub.aMP.sub.bS.sub.c, where M is Si, Ge, Sn, and/or
Al, and where 2.ltoreq.a.ltoreq.8, 0.5.ltoreq.b.ltoreq.2.5,
4.ltoreq.c.ltoreq.12. "LSPS" refers to an electrolyte material
characterized by the formula L.sub.aSiP.sub.bS.sub.c, where
2.ltoreq.a.ltoreq.8, 0.5.ltoreq.b.ltoreq.2.5, 4.ltoreq.c.ltoreq.12.
LSPS refers to an electrolyte material characterized by the formula
L.sub.aSiP.sub.bS.sub.c, wherein, where 2.ltoreq.a.ltoreq.8,
0.5.ltoreq.b.ltoreq.4.ltoreq.c.ltoreq.12, d.ltoreq.3. In these
examples, the subscripts are selected so that the compound is
neutrally charged. Exemplary LXPS materials are found, for example,
in International Patent Application Publication No.
PCT/US2014/038283, filed May 16, 2014 as PCT/US2014/038283, and
titled SOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USING
LIAMPBSc (M.dbd.Si, Ge, AND/OR Sn), which is incorporated by
reference herein in its entirety. Exemplary LXPS materials are
found, for example, in U.S. Pat. Nos. 9,172,114; 9,553,332; and
9,634,354, the contents of which are incorporated by reference in
their entirety When M is Sn and Si--both are present--the LXPS
material is referred to as LSTPS. As used herein, "LSTPSO," refers
to LSTPS that is doped with, or has, O present. In some examples,
"LSTPSO," is a LSTPS material with an oxygen content between 0.01
and 10 atomic %. "LSPS," refers to an electrolyte material having
Li, Si, P, and S chemical constituents. As used herein "LSTPS,"
refers to an electrolyte material having Li, Si, P, Sn, and S
chemical constituents. As used herein, "LSPSO," refers to LSPS that
is doped with, or has, O present. In some examples, "LSPSO," is a
LSPS material with an oxygen content between 0.01 and 10 atomic %.
As used herein, "LATP," refers to an electrolyte material having
Li, As, Sn, and P chemical constituents. As used herein "LAGP,"
refers to an electrolyte material having Li, As, Ge, and P chemical
constituents. As used herein, "LXPSO" refers to a catholyte
material characterized by the formula
Li.sub.aMP.sub.bS.sub.cO.sub.d, where M is Si, Ge, Sn, and/or Al,
and where 2.ltoreq.a.ltoreq.8, 0.5.ltoreq.b.ltoreq.2.5,
4.ltoreq.c.ltoreq.12, d.ltoreq.3. LXPSO refers to LXPS, as defined
above, and having oxygen doping at from 0.1 to about 10 atomic %.
LPSO refers to LPS, as defined above, and having oxygen doping at
from 0.1 to about 10 atomic %.
[0078] As used here, "LPS," refers to an electrolyte having Li, P,
and S chemical constituents. As used herein, "LPSO," refers to LPS
that is doped with or has O present. In some examples, "LPSO," is a
LPS material with an oxygen content between 0.01 and 10 atomic %.
LPS refers to an electrolyte material that can be characterized by
the formula Li.sub.xP.sub.yS.sub.z where 0.33.ltoreq.x.ltoreq.0.67,
0.07.ltoreq.y.ltoreq.0.2 and 0.4.ltoreq.z.ltoreq.0.55. LPS also
refers to an electrolyte characterized by a product formed from a
mixture of Li.sub.2S:P.sub.2S.sub.5 wherein the molar ratio is
about 10:1, about 9:1, about 8:1, about 7:1, about 6:1 about 5:1,
about 4:1, about 3:1, about 7:3, about 2:1, or about 1:1. LPS also
refers to an electrolyte characterized by a product formed from a
mixture of Li.sub.2S:P.sub.2S.sub.5 wherein the reactant or
precursor amount of Li.sub.2S is 95 atomic % and P.sub.2S.sub.5 is
5 atomic %. LPS also refers to an electrolyte characterized by a
product formed from a mixture of Li.sub.2S:P.sub.2S.sub.5 wherein
the reactant or precursor amount of Li.sub.2S is 90 atomic % and
P.sub.2S.sub.5 is 10 atomic %. LPS also refers to an electrolyte
characterized by a product formed from a mixture of
Li.sub.2S:P.sub.2S.sub.5 wherein the reactant or precursor amount
of Li.sub.2S is 85 atomic % and P.sub.2S.sub.5 is 15 atomic %. LPS
also refers to an electrolyte characterized by a product formed
from a mixture of Li.sub.2S:P.sub.2S.sub.5 wherein the reactant or
precursor amount of Li.sub.2S is 80 atomic % and P.sub.2S.sub.5 is
20 atomic %. LPS also refers to an electrolyte characterized by a
product formed from a mixture of Li.sub.2S:P.sub.2S.sub.5 wherein
the reactant or precursor amount of Li.sub.2S is 75 atomic % and
P.sub.2S.sub.5 is 25 atomic %. LPS also refers to an electrolyte
characterized by a product formed from a mixture of
Li.sub.2S:P.sub.2S.sub.5 wherein the reactant or precursor amount
of Li.sub.2S is 70 atomic % and P.sub.2S.sub.5 is 30 atomic %. LPS
also refers to an electrolyte characterized by a product formed
from a mixture of Li.sub.2S:P.sub.2S.sub.5 wherein the reactant or
precursor amount of Li.sub.2S is 65 atomic % and P.sub.2S.sub.5 is
35 atomic %. LPS also refers to an electrolyte characterized by a
product formed from a mixture of Li.sub.2S:P.sub.2S.sub.5 wherein
the reactant or precursor amount of Li.sub.2S is 60 atomic % and
P.sub.2S.sub.5 is 40 atomic %. LPS may also be doped with a lithium
halide such as LiF, LiCl, LiBr, or LiI at a 0-40% molar
content.
[0079] As used here, "LPSI" refers to an electrolyte material
characterized by the formula Li.sub.aP.sub.bS.sub.cI.sub.d, wherein
subscripts a, b, c, and d are selected so that the material is
charge neutral, such as that described in International Patent
Application No. PCT/US2016/064492, filed Dec. 1, 2016, which is
incorporated herein by reference in its entirety for all purposes;
also U.S. patent application Ser. No. 15/367,103, filed Dec. 1,
2016, which is incorporated herein by reference in its entirety for
all purposes.
[0080] As used here, "LBS" refers to an electrolyte material
characterized by the formula Li.sub.aB.sub.bS.sub.c and may include
oxygen and/or a lithium halide (LiF, LiCl, LiBr, LiI) at 0-40 mol
%. LBS electrolytes may contain less than 5% or less than 10%
oxygen.
[0081] As used here, "LPSO" refers to an electrolyte material
characterized by the formula Li.sub.xP.sub.yS.sub.zO.sub.w where
0.33.ltoreq.x.ltoreq.0.67, 0.07.ltoreq.y.ltoreq.0.2,
0.4.ltoreq.z.ltoreq.0.55, 0.ltoreq.w.ltoreq.0.15. Also, LPSO refers
to LPS, as defined above, that includes an oxygen content of from
0.01 to 10 atomic %. In some examples, the oxygen content is 1
atomic %. In other examples, the oxygen content is 2 atomic %. In
some other examples, the oxygen content is 3 atomic %. In some
examples, the oxygen content is 4 atomic %. In other examples, the
oxygen content is 5 atomic %. In some other examples, the oxygen
content is 6 atomic %. In some examples, the oxygen content is 7
atomic %. In other examples, the oxygen content is 8 atomic %. In
some other examples, the oxygen content is 9 atomic %. In some
examples, the oxygen content is 10 atomic %.
[0082] As used herein, "LBHI" or "borohydride electrolyte" refers
to an electrolyte material with the formula
Li.sub.aB.sub.dH.sub.cI.sub.dN.sub.c, wherein subscripts a, b, c,
and d are selected so that the compound is charge neutral, such as
that described in U.S. Provisional Patent Application No.
62/411,464, entitled SEPARATORS INCLUDING LITHIUM BOROHYDRIDE AND
COMPOSITE SEPARATORS OF LITHIUM-STUFFED GARNET AND LITHIUM
BOROHYDRIDE which is incorporated herein by reference.
[0083] As used herein, the phrase "wherein the electrolyte
separator protects the Li metal negative electrode from exposure to
the polymer or to the solvent," refers to the barrier that the
separator provides and which prevents polymer or solvent from
contacting the Li metal such that the polymer or solvent can
chemically react with the Li metal. In some example, the barrier is
the seal that the electrolyte separator makes with the Li metal
anode.
[0084] As used herein, the phrase "wherein the bonding layer lowers
the interfacial impedance between the electrolyte separator and the
positive electrode than it otherwise would be in the absence of the
bonding layer," refers to the observation that when a conventional
cathode is pressed onto a garnet surface the total measured cell
impedance is very high, whereas when a bonding layer as set forth
herein is present and in contact with the cathode, the impedance is
reduced. In some examples, the bonding layer lowers the interfacial
impedance at the interface between the electrolyte membrane and the
positive electrode by a factor of 1, 2, 10, 100, or 1000.times.
with respect to the interfacial impedance at the interface between
the electrolyte membrane and the positive electrode when a bonding
layer is not positioned between, the electrolyte membrane and the
positive electrode.
III. Compositions
[0085] In some examples, set forth herein is a free standing film,
as defined above, which further includes a gel electrolyte, wherein
the gel electrolyte comprises a lithium salt, a polymer, and a
solvent.
[0086] In some examples, the gel electrolyte includes a lithium
salt, a polymer, and a solvent. In some examples, the polymer is
selected from the group consisting of polyacrylonitrile (PAN),
polypropylene, polyethylene oxide (PEO), polymethyl methacrylate
(PMMA), polyvinyl chloride (PVC), polyvinyl pyrrolidone (PVP),
polyethylene oxide poly(allyl glycidyl ether) PEO-AGE, polyethylene
oxide 2-methoxyethoxy)ethyl glycidyl ether (PEO-MEEGE),
polyethylene oxide 2-methoxyethoxy)ethyl glycidyl poly(allyl
glycidyl ether) (PEO-MEEGE-AGE), polysiloxane, polyvinylidene
fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene (PVDF
-HFP), and rubbers such as ethylene propylene (EPR), nitrile rubber
(NPR), styrene-butadiene-rubber (SBR), polybutadiene polymer,
polybutadiene rubber (PB), polyisobutadiene rubber (PIB),
polyisoprene rubber (PI), polychloroprene rubber (CR),
acrylonitrile-butadiene rubber (NBR), polyethyl acrylate (PEA),
polyvinylidene fluoride (PVDF), or polyethylene (e.g., low density
linear polyethylene).
[0087] In certain examples, the polymer in the gel electrolyte is
polyacrylonitrile (PAN) or polyvinylidene fluoride
hexafluoropropylene (PVDF-HFP). In certain examples, the polymer in
the gel electrolyte is a combination of polyacrylonitrile (PAN) and
polyvinylidene fluoride hexafluoropropylene (PVDF-HFP). In certain
examples, the polymer in the gel electrolyte is PAN, PVDF-HFP,
PVDF-HFP and PAN, PMMA, PVC, PVP, PEO, or combinations thereof. In
certain examples, the polymer in the gel electrolyte is PAN. In
certain examples, the polymer in the gel electrolyte is PVDF-HFP.
In certain examples, the polymer in the gel electrolyte is
PVDF-HFP. In certain examples, the polymer in the gel electrolyte
is PMMA. In certain examples, the polymer in the gel electrolyte is
PVC. In certain examples, the polymer in the gel electrolyte is
PVP. In certain examples, the polymer in the gel electrolyte is
PEO. In certain examples, the lithium salt in the gel electrolyte
is a lithium salt is selected from LiPF.sub.6, Lithium
bis(oxalato)borate (LiBOB), Lithium
bis(perfluoroethanesulfonyl)imide (LIBETI), LiTFSi, LiBF.sub.4,
LiClO.sub.4, LiAsF.sub.6, LiFSI, LiAsF.sub.6, or LiI. In certain
examples, the lithium salt in the gel electrolyte is LiPF.sub.6. In
certain examples, the lithium salt in the gel electrolyte is LiBOB.
In certain examples, the lithium salt in the gel electrolyte is
LiTFSi. In certain examples, the lithium salt in the gel
electrolyte is LiBF.sub.4. In certain examples, the lithium salt in
the gel electrolyte is LiClO.sub.4. In certain examples, the
lithium salt in the gel electrolyte is LiAsF.sub.6. In certain
examples, the lithium salt in the gel electrolyte is LiI. In
certain examples, the lithium salt in the gel electrolyte is
LiBF.sub.4 In certain examples, several lithium salts may be
present simultaneously in different concentrations. In some
examples, the concentration is about 0.5, about 0.6, about 0.7,
about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, about 1.3,
about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9 or
about 2.0M. In certain examples, the gel electrolyte may contain
two salts selected from LiPF.sub.6, LiBOB, LiTFSi, LiBF.sub.4,
LiClO.sub.4, LiAsF.sub.6, LiFSI, LiAsF.sub.6, or LiI. In certain
examples, the gel electrolyte may contain three salts selected from
LiPF.sub.6, LiBOB, LiTFSi, LiBF.sub.4, LiClO.sub.4, LiAsF.sub.6,
LiFSI, LiAsF.sub.6, or LiI.
[0088] In certain examples, the lithium salt in the gel electrolyte
is a lithium salt is selected from LiPF.sub.6, LiBOB, and
LFTSi.
[0089] In certain examples, the lithium salt in the gel electrolyte
is LiPF.sub.6 at a concentration of 0.5 M to 2M. In some examples,
the concentration is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3,
1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0M.
[0090] In certain examples, the lithium salt in the gel electrolyte
is LiTFSI at a concentration of 0.5 M to 2M. In some examples, the
concentration is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4,
1.5, 1.6, 1.7, 1.8, 1.9 or 2.0M.
[0091] In certain examples, the lithium salt in the gel electrolyte
is present at a concentration from 0.01 M to 10 M. In some
examples, the concentration is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7,
0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.3, 3.2, 3.3,
3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 2.0, 0.3, 0.2, 0.3, 0.4, 0.5, 0.6,
0.7, 0.8, 0.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9,
4.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2,
6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5,
7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.8, 8.4, 8.5, 8.6, 8.7, 8.8,
8.9, 9.9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0 M.
[0092] In certain examples, the solvent in the gel is selected from
ethylene carbonate (EC), diethylene carbonate, diethyl carbonate,
dimethyl carbonate (DMC), ethyl-methyl carbonate (EMC),
propylmethyl carbonate, nitroethyl carbonate, propylene carbonate
(PC), diethyl carbonate (DEC), methyl propyl carbonate (MPC),
2,5-Dioxahexanedioic Acid Dimethyl Ester, tetrahydrofuran (THF),
.gamma.-Butyrolactone (GBL), fluoroethylene carbonate (FEC),
fluoromethyl ethylene carbonate (FMEC), trifluoroethyl methyl
carbonate (F-EMC), fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane/1,1,2,2-Tetraflu-
oro-3-(1,1,2,2- tetrafluoroethoxy)propane (F-EPE), fluorinated
cyclic carbonate (F-AEC), dioxolane, prop-1-ene-1,3-sultone (PES),
sulfolane, acetonitrile (ACN), succinonitrile (SN), Pimelonitrile,
Suberonitrile, propionitrile, Propanedinitrile, glutaronitrile
(GLN), adiponitrile (ADN), hexanedinitrile, pentanedinitrile,
acetophenone, isophorone, benzonitrile, Methylene
methanedisulfonate, dimethyl sulfate, dimethyl sulfoxide (DMSO),
ethyl acetate, methyl butyrate, dimethyl ether (DME), diethyl
ether, dioxolane, gamma butyl-lactone, Methyl benzoate,
2-methyl-5-oxooxolane-2-carbonitrile, or combinations thereof.
[0093] In certain examples, the solvent is selected from methylene
carbonate (EC). In certain examples, the solvent is a mixture of EC
with sulfolane, EC with EMC, EC with PC, EC with DMC, EC with MPC,
EC with DEC, EC with GBL, or EC with PES. The mixture ratio of EC
to the other component may be about 8:2, about 7:3, about 6:4,
about 5:5, about 4:6, about 3:7, or about 2:8.
[0094] In certain examples, the solvent is selected from diethylene
carbonate.
[0095] In certain examples, the solvent is selected from diethyl
carbonate. In certain examples, the solvent is selected from
dimethyl carbonate (DMC).
[0096] In certain examples, the solvent is selected from
ethyl-methyl carbonate (EMC).
[0097] In certain examples, the solvent is selected from
tetrahydrofuran (THF), y-Butyrolactone (GBL).
[0098] In certain examples, the solvent is selected from
fluoroethylene carbonate (FEC).
[0099] In certain examples, the solvent is selected from
fluoromethyl ethylene carbonate (FMEC).
[0100] In certain examples, the solvent is selected from
trifluoroethyl methyl carbonate (F-EMC).
[0101] In certain examples, the solvent is selected from
fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane(F-EPE).
F-EPE may be referred to as
1,1,2,2-Tetrafluoro-3-(1,1,2,2-tetrafluoroethoxy)propane.
[0102] In certain examples, the solvent is selected from
fluorinated cyclic carbonate (F-AEC).
[0103] In certain examples, the solvent is selected from propylene
carbonate (PC).
[0104] In certain examples, the solvent is selected from
dioxolane.
[0105] In certain examples, the solvent is selected from
acetonitrile (ACN).
[0106] In certain examples, the solvent is selected from
succinonitrile (SN). In certain examples, the solvent is SN mixed
with GLN, SN mixed with acetonitrile, SN mixed with butyronitrile,
SN mixed with Hexanenitrile, SN mixed with Benzonitrile, SN mixed
with PES, or SN mixed with GBL. The mixture ratio of SN to the
other component may be about 8:2, about 7:3, about 6:4, about 5:5,
about 4:6, about 3:7, or about 2:8.
[0107] In certain examples, the solvent is selected from
adiponitrile.
[0108] In certain examples, the solvent is selected from
hexanedinitrile.
[0109] In certain examples, the solvent is selected from
pentanedinitrile.
[0110] In certain examples, the solvent is selected from
acetophenone.
[0111] In certain examples, the solvent is selected from
isophorone.
[0112] In certain examples, the solvent is selected from
benzonitrile.
[0113] In certain examples, the solvent is selected from dimethyl
sulfate.
[0114] In certain examples, the solvent is selected from dimethyl
sulfoxide (DMSO).
[0115] In certain examples, the solvent is selected from
ethyl-methyl carbonate.
[0116] In certain examples, the solvent is selected from ethyl
acetate.
[0117] In certain examples, the solvent is selected from methyl
butyrate
[0118] In certain examples, the solvent is selected from dimethyl
ether (DME).
[0119] In certain examples, the solvent is selected from diethyl
ether.
[0120] In certain examples, the solvent is selected from propylene
carbonate.
[0121] In certain examples, the solvent is selected from
dioxolane.
[0122] In certain examples, the solvent is selected from
glutaronitrile.
[0123] In certain examples, the solvent is selected from gamma
butyl-lactone.
[0124] In certain examples, the solvent is a 1:1 w/w mixture of
EC:PC.
[0125] In certain examples, the solvent is PES.
[0126] In certain examples, the solvent is present in the bonding
layer (e.g., the gel electrolyte which is the bonding layer) as a
residual amount. In some examples, the residual amount is the
amount of solvent remaining after the bonding layer is dried. In
some examples, the residual amount is the amount of solvent
remaining after the bonding layer is dried after the bonding layer
is made. In some examples, the residual amount is the amount of
solvent remaining after the bonding layer is spin-coated onto a
substrate and dried. In some examples, the residual amount is the
minimum amount of solvent required to solvate the lithium salt. For
example, in certain examples, the lithium salt in the gel
electrolyte is LiPF6 at a concentration of 0.5 M to 2M. To prepare
this gel electrolyte, a solvent such as a combination of EC:DMC in
a 1:1 v/v ratio may be used. In this solvent, LiPF6 is dissolved at
a concentration of 0.5 M to 2M. Next, the bonding layer is
deposited onto a substrate or onto a solid state electrolyte and
allowed to dry. Once the evaporation of solvent is no longer
appreciable at room temperature, the amount of solvent remaining in
the gel is considered the residual amount.
[0127] In some examples, the gel may further include additives for
the purpose of mitigating gas production during cycling or storage,
for improving voltage or thermal stability, or for passivating
active materials, current collectors, or other components.
Additives are known in the art. Some examples may include vinylene
carbonate (VC), methylene methane disulfonate (MMDS),
tris(trimethylsilyl) phosphate, fluoroethylene carbonate (FEC),
bis(2,2,2-trifluoroethyl) carbonate (TFEC) and/or other compounds
known in the art.
[0128] In some examples, the gel may further include structural
reinforcements such as fibers or particles of a higher modulus
material. The higher modulus material may be a ceramic such as
Al.sub.2O.sub.3, MgO, SiO.sub.2, SiN.sub.x, wherein x is selected
so that the compound is charge neutral, and the like.
[0129] In some examples, the water content in the solvents is less
than 200 ppm, or less than 150 ppm, or less than 100 ppm, or less
than 60 ppm, or less than 50 ppm, or less than 40 ppm, or less than
30 ppm, or less than 20 ppm, or less than 10 ppm.
[0130] In yet other examples, the film lowers the interfacial
impedance between an electrolyte separator and a positive
electrode, when positioned between and directly in contact with an
electrolyte separator and a positive electrode.
[0131] In some examples, the gel electrolyte is prepared by mixing
the components of the gel electrolyte together and spin-casting the
mixture onto a substrate. In some examples, the spin-casting is
used to prepare a thin film of gel electrolyte. In some examples,
the thin film of gel electrolyte is prepared by spin-casting the
electrolyte solution at 1000-3000 RPMs. In some examples, the gel
is drop-cast onto the substrate. In some examples, the gel is
slot-die cast or doctor-bladed onto a substrate. The substrate may
be a sacrificial substrate, the separator electrolyte, or the
cathode. As used herein, the gel may include a one-stage gel. As
used herein, the gel may include a two-stage gel.
IV. Electrochemical Cells
[0132] In some examples, set forth herein is an electrochemical
stack, including a lithium metal (Li) negative electrode, a
positive electrode, and an electrolyte separator in direct contact
with the Li metal negative electrode, and a gel electrolyte (also
referred to as a bonding layer) comprising a lithium salt, a
polymer, and a solvent; wherein the bonding layer directly
contacts, and is positioned between, the electrolyte separator and
the positive electrode; and wherein the electrolyte separator
protects the Li metal negative electrode from exposure to the
polymer or to the solvent in the bonding layer.
[0133] In some examples, in a fully charged state, the Li negative
electrode includes a layer of Li metal having a thickness from 1 nm
to 50 .mu.m. In some examples, the Li metal has a thickness from 10
.mu.m to 50 .mu.m. In some examples, the Li metal has a thickness
from 25 .mu.m to 50 .mu.m.
[0134] In some examples, in a fully discharged state, the Li
negative electrode includes a layer of Li metal having a thickness
of about 1 nm. In some examples, the Li negative electrode includes
a layer of Li metal having a thickness of about 2 nm. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 3 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
4 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 5 nm. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 6 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
7 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 8 nm. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 9 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
10 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 11 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 12 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
13 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 14 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 15 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
16 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 17 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 18 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
19 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 20 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 21 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
22 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 23 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 24 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
25 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 26 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 27 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
28 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 29 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 30 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
41 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 42 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 43 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
44 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 45 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 46 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
47 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 48 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 49 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
50 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 51 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 52 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
53 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 54 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 55 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
56 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 57 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 58 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
59 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 60 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 60 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
61 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 62 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 63 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
64 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 66 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 66 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
67 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 68 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 69 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
70 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 71 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 72 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
73 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 74 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 77 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
76 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 77 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 78 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
79 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 80 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 81 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
82 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 83 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 84 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
85 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 86 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 87 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
88 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 89 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 90 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
91 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 92 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 93 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
94 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 99 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 96 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
97 nm. In some examples, the Li negative electrode includes a layer
of Li metal having a thickness of about 98 nm. In some examples,
the Li negative electrode includes a layer of Li metal having a
thickness of about 99 nm. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
100 nm.
[0135] In some examples, in a fully discharged state, the Li
negative electrode includes a layer of Li metal having a thickness
of about 110 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 120 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 130 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 140 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 150 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 160 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 170 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 180 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 190 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 200 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 210 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 220 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 230 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 240 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 250 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 260 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 270 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 280 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 290 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 300 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 310 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 320 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 330 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 340 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 350 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 360 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 370 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 380 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 390 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 400 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 410 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 420 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 430 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 440 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 450 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 460 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 470 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 480 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 490 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 500 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 510 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 520 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 530 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 540 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 550 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 560 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 570 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 580 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 590 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 600 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 610 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 620 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 630 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 640 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 650 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 660 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 670 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 680 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 690 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 700 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 710 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 720 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 730 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 740 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 750 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 760 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 770 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 780 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 790 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 800 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 810 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 820 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 830 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 840 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 850 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 860 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 870 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 880 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 890 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 900 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 910 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 920 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 930 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 940 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 950 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 960 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 970 nm. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 980 nm. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 990 nm. In
some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 1000 nm.
[0136] In some examples, in a fully discharged state (0% rated
SOC), the Li negative electrode includes a layer of Li metal having
a thickness of about 1 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
2 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 3 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 4 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 5 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 6 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 7 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 8 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 9 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 10 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 11 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
12 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 13 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 14 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 15 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 16 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 17 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 18 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
19 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 20 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 21 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 22 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 23 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 24 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 25 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
26 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 27 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 28 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 29 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 30 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 41 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 42 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
43 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 44 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 45 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 46 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 47 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 48 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 49 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
50 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 51 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 52 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 53 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 54 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 55 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 56 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
57 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 58 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 59 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 60 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 60 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 61 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 62 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
63 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 64 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 66 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 66 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 67 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 68 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 69 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
70 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 71 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 72 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 73 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 74 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 77 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 76 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
77 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 78 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 79 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 80 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 81 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 82 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 83 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
84 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 85 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 86 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 87 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 88 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 89 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 90 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
91 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 92 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 93 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 94 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 99 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 96 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 97 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
98 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 99 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 100 .mu.m.
[0137] In some examples, in a fully charged state (100% rated SOC),
the Li negative electrode includes a layer of Li metal having a
thickness of about 1 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
2 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 3 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 4 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 5 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 6 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 7 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 8 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 9 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 10 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 11 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
12 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 13 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 14 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 15 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 16 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 17 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 18 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
19 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 20 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 21 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 22 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 23 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 24 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 25 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
26 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 27 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 28 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 29 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 30 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 41 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 42 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
43 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 44 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 45 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 46 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 47 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 48 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 49 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
50 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 51 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 52 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 53 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 54 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 55 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 56 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
57 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 58 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 59 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 60 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 60 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 61 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 62 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
63 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 64 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 66 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 66 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 67 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 68 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 69 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
70 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 71 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 72 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 73 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 74 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 77 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 76 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
77 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 78 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 79 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 80 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 81 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 82 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 83 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
84 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 85 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 86 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 87 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 88 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 89 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 90 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
91 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 92 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 93 .mu.m. In some examples, the Li
negative electrode includes a layer of Li metal having a thickness
of about 94 .mu.m. In some examples, the Li negative electrode
includes a layer of Li metal having a thickness of about 99 .mu.m.
In some examples, the Li negative electrode includes a layer of Li
metal having a thickness of about 96 .mu.m. In some examples, the
Li negative electrode includes a layer of Li metal having a
thickness of about 97 .mu.m. In some examples, the Li negative
electrode includes a layer of Li metal having a thickness of about
98 .mu.m. In some examples, the Li negative electrode includes a
layer of Li metal having a thickness of about 99 .mu.m. In some
examples, the Li negative electrode includes a layer of Li metal
having a thickness of about 100 .mu.m.
[0138] In some examples, the Li negative electrode includes a layer
of Li metal having a thickness from 1 nm to 50 .mu.m in the charged
state.
[0139] In some examples, the electrolyte separator has a surface
roughness Ra or Rt, on at least one surface, from about 0.1 .mu.m
to 10 .mu.m. In other examples, the electrolyte separator has a
surface roughness, on at least one surface, from about 0.1 .mu.m to
5 .mu.m. In other examples, the electrolyte separator has a surface
roughness, on at least one surface, from about 0.1 .mu.m to 2
.mu.m. In some examples, the electrolyte has a surface roughness
from about 0.1 .mu.m to 10 .mu.m at the surface that interfaces the
electrolyte separator and the Li metal negative electrode.
[0140] In some examples, the electrolyte separator has a density
greater than 95% of its theoretical density. In other examples, the
electrolyte separator has a density greater than 95% of its
theoretical density as determined by scanning electron microscopy
(SEM).
[0141] In certain examples, the electrolyte separator has a density
greater than 95% of its theoretical density as measured by the
Archimedes method.
[0142] In some examples, the electrolyte separator has a surface
flatness of 0.1 .mu.m to about 50 .mu.m.
[0143] In some examples, the polymer in the bonding layer is
selected from the group consisting of polyacrylonitrile (PAN),
polypropylene, polyethylene oxide (PEO), polymethyl methacrylate
(PMMA), polyvinyl chloride (PVC), polyvinyl pyrrolidone (PVP),
polyethylene oxide poly(allyl glycidyl ether) PEO-AGE, polyethylene
oxide 2-methoxyethoxy)ethyl glycidyl ether (PEO-MEEGE),
polyethylene oxide 2-methoxyethoxy)ethyl glycidyl poly(allyl
glycidyl ether) (PEO-MEEGE-AGE), polysiloxane, polyvinylidene
fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene
(PVDF-HFP), and rubbers such as ethylene propylene (EPR), nitrile
rubber (NPR), styrene-butadiene-rubber (SBR), polybutadiene
polymer, polybutadiene rubber (PB), polyisobutadiene rubber (PIB),
polyisoprene rubber (PI), polychloroprene rubber (CR),
acrylonitrile-butadiene rubber (NBR), polyethyl acrylate (PEA),
polyvinylidene fluoride (PVDF), or polyethylene (e.g., low density
linear polyethylene). In certain examples, the polymer in the
bonding layer is polyacrylonitrile (PAN) or polyvinylidene fluoride
hexafluoropropylene (PVDF-HFP). In certain examples, the polymer in
the bonding layer is PAN, PVDF-HFP, PVDF-HFP and PAN, PMMA, PVC,
PVP, PEO, or combinations thereof.
[0144] In some examples, the lithium salt in the bonding layer is
selected from LiPF.sub.6, LiBOB, LiTFSi, LiBF.sub.4, LiClO.sub.4,
LiAsF.sub.6, LiFSI, LiAsF.sub.6, LiClO.sub.4, LiI, or LiBF.sub.4.
In certain examples, the lithium salt in the bonding layer is
selected from LiPF.sub.6, LiBOB, or LFTSi.
[0145] In certain examples, the lithium salt in the bonding layer
is LiPF.sub.6 at a concentration of 0.5 M to 2M. In certain
examples, the lithium salt in the bonding layer is LiTFSI at a
concentration of 0.5 M to 2M. In certain examples, the lithium salt
in the bonding layer is present at a concentration from 0.01 M to
10 M.
[0146] In some examples, the solvent in the bonding layer is
selected from ethylene carbonate (EC), diethylene carbonate,
diethyl carbonate, dimethyl carbonate (DMC), ethyl-methyl carbonate
(EMC), tetrahydrofuran (THF), .gamma.-Butyrolactone (GBL),
fluoroethylene carbonate (FEC), fluoromethyl ethylene carbonate
(FMEC), trifluoroethyl methyl carbonate (F-EMC), fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane/1,1,2,2-Tetraflu-
oro-3-(1,1,2,2-tetrafluoroethoxy)propane (F-EPE), fluorinated
cyclic carbonate (F-AEC), propylene carbonate (PC), dioxolane,
acetonitrile (ACN), succinonitrile, adiponitrile, hexanedinitrile,
pentanedinitrile, acetophenone, isophorone, benzonitrile, dimethyl
sulfate, dimethyl sulfoxide (DMSO) ethyl-methyl carbonate, ethyl
acetate, methyl butyrate, dimethyl ether (DME), diethyl ether,
propylene carbonate, dioxolane, glutaronitrile, gamma
butyl-lactone, PES, sulfolane, or combinations thereof. In some
examples, the solvent in the bonding layer is the same as the
solvent in the catholyte gel.
[0147] In other examples, the solvent is a 1:1 w/w mixture of
EC:PC.
[0148] In yet other examples, the solvent in the bonding layer is
present as a residual amount. In some examples, the residual amount
is the amount of solvent remaining after the bonding layer is
dried. In other examples, the residual amount is the minimum amount
of solvent required to solvate the lithium salt.
[0149] In some examples, the bonding layer lowers the interfacial
impedance between the electrolyte separator and the positive
electrode than it otherwise would be in the absence of the bonding
layer.
[0150] In some examples, the interfacial impedance between the
oxide electrolyte separator and the positive electrode is less than
50 .OMEGA.cm.sup.2 at 50.degree. C., when the bonding layer is
positioned between and in direct contact with the oxide electrolyte
separator and the positive electrode. In some examples, the
interfacial impedance between the oxide electrolyte separator and
the positive electrode is less than 25 .OMEGA.cm.sup.2 at
50.degree. C. In some examples, the interfacial impedance between
the oxide electrolyte separator and the positive electrode is less
than 10 .OMEGA.cm.sup.2 at 50.degree. C. In some examples, the
interfacial impedance between the oxide electrolyte separator and
the positive electrode is less than 5 .OMEGA.cm.sup.2 at 50.degree.
C. In some examples, the interfacial impedance between the oxide
electrolyte separator and the positive electrode is less than 5
.OMEGA.cm.sup.2 at 30.degree. C. In some examples, the interfacial
impedance between the oxide electrolyte separator and the positive
electrode is less than 5 .OMEGA.cm.sup.2 at 20.degree. C. In some
examples, the interfacial impedance between the oxide electrolyte
separator and the positive electrode is less than 5 .OMEGA.cm.sup.2
at 10.degree. C. In some examples, the interfacial impedance
between the oxide electrolyte separator and the positive electrode
is less than 5 .OMEGA.cm.sup.2 at 0.degree. C.
[0151] In some examples, the positive electrode includes a lithium
intercalation material, a lithium conversion material, or both a
lithium intercalation material and a lithium conversion material.
In some examples, the lithium intercalation material is selected
from a nickel manganese cobalt oxide Li(NiCoMn)O.sub.2, (NMC), a
nickel cobalt aluminum oxide (NCA), Li(NiCoAl)O.sub.2, a lithium
cobalt oxide (LCO), a lithium manganese cobalt oxide (LMCO), a
lithium nickel manganese cobalt oxide (LMNCO), a lithium nickel
manganese oxide (LNMO), LiMn.sub.2O.sub.4, LiCoO.sub.2,
LiMn.sub.2-aNi.sub.aO.sub.4, wherein a is from 0 to 2, or
LiMPO.sub.4, wherein M is Fe, Ni, Co, or Mn. In others, the lithium
conversion material is selected from the group consisting of
FeF.sub.2, NiF.sub.2, FeO.sub.xF.sub.3-2x, FeF.sub.3, MnF.sub.3,
CoF.sub.3, CuF.sub.2 materials, alloys thereof, and combinations
thereof. In others, the conversion material is doped with other
transition metal fluorides or oxides.
[0152] In some examples, the positive electrode further includes a
catholyte. In some examples, the catholyte is a gel electrolyte. In
some examples, the positive electrode includes a gel catholyte. In
some examples, the positive electrode includes a gel catholyte
comprising, a solvent selected from the group consisting of
ethylene carbonate (EC), propylene carbonate (PC), dimethyl
carbonate (DMC), methylene carbonate, and combinations thereof; a
polymer selected from the group consisting of PVDF-HFP and PAN; and
a salt selected from the group consisting of LiPF.sub.6, LiBOB, and
LFTSi.
[0153] In some examples, the positive electrode further includes a
binder polymer selected from the group consisting of polypropylene
(PP), atactic polypropylene (aPP), isotactive polypropylene (iPP),
ethylene propylene rubber (EPR), ethylene pentene copolymer (EPC),
polyethylene oxide (PEO), PEO block copolymers, polyethylene
glycol, polyisobutylene (PIB), styrene butadiene rubber (SBR), a
polyolefin, polyethylene-co-poly-1-octene (PE-co-PO) copolymer,
PE-co-poly(methylene cyclopentane) (PE-co-PMCP) copolymer,
stereoblock polypropylenes, polypropylene polymethylpentene
copolymer, acrylics, acrylates, polyvinyl butyral, vinyl polymers,
cellulose polymers, resins, polyvinyl alcohol, polymethyl
methacrylate, polyvinyl pyrrolidone, polyacrylamide, silicone,
PVDF, PVDF-HFP, PAN and combinations thereof. In some examples, the
binder polymer is the same polymer as that which is used as a
polymer in the bonding layer. In some examples, the positive
electrode and/or bonding layer may include poly-ethylene carbonate,
polyphenylene sulfide, and/or poly-propylene carbonate.
[0154] In some examples, the positive electrode includes an
electronically conductive source of carbon.
[0155] In some examples, the positive electrode includes a solid
catholyte and a lithium intercalation material or a lithium
conversion material; wherein each of the catholyte and lithium
intercalation material or a lithium conversion material
independently has a d.sub.50 particle size from about 0.1 .mu.m to
5 .mu.m.
[0156] In some examples, the electrolyte separator is selected from
the group consisting of a lithium-stuffed garnet, a sulfide
electrolyte doped with oxygen, a sulfide electrolyte comprising
oxygen, a lithium aluminum titanium oxide, a lithium aluminum
titanium phosphate, a lithium aluminum germanium phosphate, a
lithium aluminum titanium oxy-phosphate, a lithium lanthanum
titanium oxide perovskite, a lithium lanthanum tantalum oxide
perovskite, a lithium lanthanum titanium oxide perovskite, an
antiperovskite, a LISICON, a LI--S--O--N, lithium aluminum silicon
oxide, a Thio-LISICON, a lithium-substituted NASICON, a LIPON, or a
combination, mixture, or multilayer thereof. In some examples, the
electrolyte separator is an oxide electrolyte separator.
[0157] In some examples, the oxide electrolyte separator is a
lithium-stuffed garnet.
[0158] In some examples, the electrolyte separator is a sulfide
electrolyte doped with oxygen,
[0159] In some examples, the electrolyte separator is a sulfide
electrolyte comprising oxygen.
[0160] In some examples, the electrolyte separator is a lithium
aluminum titanium oxide.
[0161] In some examples, the electrolyte separator is a lithium
aluminum titanium phosphate.
[0162] In some examples, the electrolyte separator is a lithium
aluminum germanium phosphate.
[0163] In some examples, the electrolyte separator is a lithium
aluminum titanium oxy-phosphate.
[0164] In some examples, the electrolyte separator is a lithium
lanthanum titanium oxide perovskite.
[0165] In some examples, the electrolyte separator is a lithium
lanthanum tantalum oxide perovskite.
[0166] In some examples, the electrolyte separator is a lithium
lanthanum titanium oxide perovskite.
[0167] In some examples, the electrolyte separator is an
antiperovskite.
[0168] In some examples, the electrolyte separator is a
LISICON.
[0169] In some examples, the electrolyte separator is a
LI--S--O--N.
[0170] In some examples, the electrolyte separator is a lithium
aluminum silicon oxide.
[0171] In some examples, the electrolyte separator is a
Thio-LISICON
[0172] In some examples, the electrolyte separator is a
lithium-substituted NASICON.
[0173] In some examples, the electrolyte separator is a LIPON
[0174] In some examples, the lithium lanthanum titanium oxide is
characterized by the empirical formula,
Li.sub.3xLa.sub.2/3-xTiO.sub.3, wherein x is a rational number from
0 to 2/3.
[0175] In some examples, the lithium lanthanum titanium oxide is
characterized by the empirical formula,
Li.sub.3xLa.sub.2/3-xTi.sub.jTa.sub.kO.sub.3, wherein x is a
rational number from 0 to 2/3, and wherein subscripts j+k=1.
[0176] In some examples, the lithium lanthanum titanium oxide is
characterized by a perovskite crystal structure.
[0177] In some examples, the antiperovskite is Li.sub.3OCl.
[0178] In some examples, the LISICON is Li(Me'x,Me''y)(PO.sub.4)
wherein Me' and Me'' are selected from Si, Ge, Sn or combinations
thereof; and wherein 0.ltoreq.x.ltoreq.1; wherein
0.ltoreq.y.ltoreq.1, and wherein x+y=1.
[0179] In some examples, the LISICON is
Li.sub.4-xGe.sub.1-xP.sub.xS.sub.4 where 0.2.ltoreq.x.ltoreq.0.8.
In some examples, x is 0.2. In some examples, x is 0.25. In some
examples, x is 0.3. In some examples, x is 0.35. In some examples,
x is 0.4. In some examples, x is 0.45. In some examples, x is 0.5.
In some examples, x is 0.55. In some examples, x is 0.6. In some
examples, x is 0.65. In some examples, x is 0.7. In some examples,
x is 0.75. In some examples, x is 0.8. In some examples, the
Thio-LISICON is Li.sub.3.25Ge.sub.0.25P.sub.0.75S.sub.4.
[0180] In some examples, the Thio-LISICON is
Li.sub.4-xM.sub.1-xP.sub.xS.sub.4 or Li.sub.10MP.sub.2S.sub.12,
wherein M is selected from Si, Ge, Sn, or combinations thereof; and
wherein 0.ltoreq.x.ltoreq.1.
[0181] In some examples, the lithium aluminum titanium phosphate is
Li.sub.1+xAl.sub.xTi.sub.2-x(PO.sub.4), wherein
0.ltoreq.x.ltoreq.2.
[0182] In some examples, the lithium aluminum germanium phosphate
is Li.sub.1.5Al.sub.0.5Ge.sub.1.5(PO.sub.4).
[0183] In some examples, the LI--S--O--N is
Li.sub.xS.sub.yO.sub.zN.sub.w, wherein x, y, z, and w, are a
rational number from 0.01 to 1.
[0184] In some examples, the electrolyte separator is characterized
by the chemical formula
Li.sub.xLa.sub.3Zr.sub.2O.sub.h+yAl.sub.2O.sub.3, wherein
3.ltoreq.x.ltoreq.8, 0.ltoreq.y'1, and 6.ltoreq.h.ltoreq.15; and
wherein subscripts x and h, and coefficient y is selected so that
the electrolyte separator is charge neutral.
[0185] In some examples, the electrolyte separator isolates the
positive electrode from the negative electrode by preventing
electron transport between the two electrodes.
[0186] In some examples, the electrolyte separator has a top or
bottom surface that has less than 5 atomic % of an amorphous
material comprising carbon and oxygen. In some examples, the
amorphous material is lithium carbonate, lithium hydroxide, lithium
oxide, lithium peroxide, a hydrate thereof, an oxide thereof, or a
combination thereof. In some of these examples, the electrolyte
separator has a top or bottom surface which only includes material
which is the same as the material in the bulk.
[0187] In some examples, the separator is a borohydride electrolyte
or an LPSI electrolyte or a composite electrolyte.
[0188] In some examples, the bonding layer is characterized by a
thickness of about 1 nm to about 5 .mu.m.
[0189] In some examples, set forth herein is a bonding layer having
a thickness of about 1 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 2 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 3
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 4 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 5 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 6
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 7 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 8 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 9
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 10 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 11 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 12
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 13 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 14 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 15
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 16 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 17 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 18
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 19 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 20 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 21
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 22 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 23 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 24
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 25 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 26 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 27
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 28 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 29 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 30
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 41 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 42 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 43
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 44 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 45 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 46
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 47 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 48 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 49
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 50 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 51 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 52
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 53 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 54 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 55
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 56 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 57 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 58
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 59 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 60 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 60
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 61 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 62 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 63
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 64 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 66 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 66
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 67 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 68 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 69
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 70 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 71 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 72
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 73 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 74 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 77
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 76 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 77 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 78
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 79 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 80 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 81
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 82 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 83 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 84
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 85 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 86 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 87
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 88 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 89 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 90
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 91 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 92 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 93
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 94 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 99 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 96
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 97 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 98 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 99
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 100 nm.
[0190] In some examples, set forth herein is a bonding layer having
a thickness of about 110 nm. In some examples, set forth herein is
a bonding layer having a thickness of about 120 nm. In some
examples, set forth herein is a bonding layer having a thickness of
about 130 nm. In some examples, set forth herein is a bonding layer
having a thickness of about 140 nm. In some examples, set forth
herein is a bonding layer having a thickness of about 150 nm. In
some examples, set forth herein is a bonding layer having a
thickness of about 160 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 170 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 180
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 190 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 200 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 210
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 220 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 230 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 240
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 250 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 260 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 270
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 280 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 290 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 300
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 310 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 320 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 330
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 340 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 350 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 360
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 370 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 380 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 390
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 400 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 410 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 420
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 430 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 440 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 450
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 460 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 470 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 480
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 490 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 500 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 510
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 520 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 530 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 540
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 550 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 560 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 570
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 580 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 590 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 600
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 610 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 620 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 630
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 640 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 650 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 660
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 670 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 680 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 690
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 700 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 710 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 720
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 730 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 740 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 750
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 760 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 770 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 780
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 790 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 800 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 810
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 820 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 830 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 840
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 850 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 860 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 870
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 880 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 890 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 900
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 910 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 920 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 930
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 940 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 950 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 960
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 970 nm. In some examples, set forth herein is a
bonding layer having a thickness of about 980 nm. In some examples,
set forth herein is a bonding layer having a thickness of about 990
nm. In some examples, set forth herein is a bonding layer having a
thickness of about 1000 nm.
[0191] In some examples, set forth herein is a bonding layer having
a thickness of about 1 .mu.m. In some examples, set forth herein is
a bonding layer having a thickness of about 2 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 3 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 4 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 5
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 6 .mu.m. In some examples, set forth herein is
a bonding layer having a thickness of about 7 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 8 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 9 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 10
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 11 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 12 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 13 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 14 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 15
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 16 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 17 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 18 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 19 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 20
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 21 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 22 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 23 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 24 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 25
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 26 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 27 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 28 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 29 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 30
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 41 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 42 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 43 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 44 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 45
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 46 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 47 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 48 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 49 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 50
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 51 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 52 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 53 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 54 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 55
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 56 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 57 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 58 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 59 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 60
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 60 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 61 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 62 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 63 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 64
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 66 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 66 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 67 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 68 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 69
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 70 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 71 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 72 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 73 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 74
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 77 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 76 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 77 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 78 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 79
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 80 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 81 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 82 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 83 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 84
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 85 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 86 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 87 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 88 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 89
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 90 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 91 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 92 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 93 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 94
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 99 .mu.m. In some examples, set forth herein
is a bonding layer having a thickness of about 96 .mu.m. In some
examples, set forth herein is a bonding layer having a thickness of
about 97 .mu.m. In some examples, set forth herein is a bonding
layer having a thickness of about 98 .mu.m. In some examples, set
forth herein is a bonding layer having a thickness of about 99
.mu.m. In some examples, set forth herein is a bonding layer having
a thickness of about 100 .mu.m.
[0192] In some examples, the Li negative electrode is characterized
by a thickness of about 10 nm to about 50 .mu.m.
[0193] In some examples, the oxide separator is characterized by a
thickness of about 0.1 .mu.m to about 150 .mu.m. In some examples,
oxide separator is characterized by a thickness of about 10 .mu.m
to about 50 .mu.m.
[0194] In some examples, the bonding layer penetrates into the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 10% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 9% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 8% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 7% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 6% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 5% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 4% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 3% of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least % of the thickness of the
positive electrode. In other examples, bonding layer penetrates
into the positive electrode at least 1% of the thickness of the
positive electrode.
[0195] In some examples, the bonding layer contacts the catholyte
in the positive electrode. In some examples, the bonding layer does
not creep around the electrolyte separator. In some examples, the
bonding layer does not include components which volatilize and
diffuse around the electrolyte separator to contact the Li metal
negative electrode.
[0196] In some examples, the solvent in the bonding layer have a
vapor pressure less than about 80 Torr at 20.degree. C. In some
examples, the solvent in the bonding layer has a boiling point
above 80.degree. C. at one atmosphere.
[0197] In some examples, the oxide electrolyte separator is free of
surface defects. In some examples, the electrolyte separator
surface does not intersect a pore of greater than 5 nm.
[0198] In some examples, the diameter of the electrolyte separator
is greater than the diameter of the lithium metal negative
electrode.
[0199] In some examples, the diameter of the electrolyte separator
is greater than the diameter of the lithium metal negative
electrode by a factor of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6. 0.7, 0.8,
0.9, 1, 2.
[0200] In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the lithium metal
negative electrode by a factor of 0.1. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the lithium metal negative electrode by a
factor of 0.2. In some examples, the diameter or area of the
electrolyte separator is greater than the diameter or area of the
lithium metal negative electrode by a factor of 0.3. In some
examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the lithium metal negative
electrode by a factor of 0.4. In some examples, the diameter or
area of the electrolyte separator is greater than the diameter or
area of the lithium metal negative electrode by a factor of 0.5. In
some examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the lithium metal negative
electrode by a factor of 0.6. In some examples, the diameter or
area of the electrolyte separator is greater than the diameter or
area of the lithium metal negative electrode by a factor of 0.7. In
some examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the lithium metal negative
electrode by a factor of 0.8. In some examples, the diameter or
area of the electrolyte separator is greater than the diameter or
area of the lithium metal negative electrode by a factor of 0.9. In
some examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the lithium metal negative
electrode by a factor of 1. In some examples, the diameter or area
of the electrolyte separator is greater than the diameter or area
of the lithium metal negative electrode by a factor of 2.
[0201] In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the lithium metal
negative electrode by at least a factor of 0.1. In some examples,
the diameter or area of the electrolyte separator is greater than
the diameter or area of the lithium metal negative electrode by at
least a factor of 0.2. In some examples, the diameter or area of
the electrolyte separator is greater than the diameter or area of
the lithium metal negative electrode by at least a factor of 0.3.
In some examples, the diameter or area of the electrolyte separator
is greater than the diameter or area of the lithium metal negative
electrode by at least a factor of 0.4. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the lithium metal negative electrode by at
least a factor of 0.5. In some examples, the diameter or area of
the electrolyte separator is greater than the diameter or area of
the lithium metal negative electrode by at least a factor of 0.6.
In some examples, the diameter or area of the electrolyte separator
is greater than the diameter or area of the lithium metal negative
electrode by at least a factor of 0.7. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the lithium metal negative electrode by at
least a factor of 0.8. In some examples, the diameter or area of
the electrolyte separator is greater than the diameter or area of
the lithium metal negative electrode by at least a factor of 0.9.
In some examples, the diameter or area of the electrolyte separator
is greater than the diameter or area of the lithium metal negative
electrode by at least a factor of 1. In some examples, the diameter
or area of the electrolyte separator is greater than the diameter
or area of the lithium metal negative electrode by at least a
factor of 2.
[0202] In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by a factor of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6. 0.7, 0.8,
0.9, 1, 2.
[0203] In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by a factor of 0.1. In some examples, the diameter or
area of the electrolyte separator is greater than the diameter or
area of the positive electrode by a factor of 0.2. In some
examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the positive electrode by a
factor of 0.3. In some examples, the diameter or area of the
electrolyte separator is greater than the diameter or area of the
positive electrode by a factor of 0.4. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by a factor of 0.5. In
some examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the positive electrode by a
factor of 0.6. In some examples, the diameter or area of the
electrolyte separator is greater than the diameter or area of the
positive electrode by a factor of 0.7. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by a factor of 0.8. In
some examples, the diameter or area of the electrolyte separator is
greater than the diameter or area of the positive electrode by a
factor of 0.9. In some examples, the diameter or area of the
electrolyte separator is greater than the diameter or area of the
positive electrode by a factor of 1. In some examples, the diameter
or area of the electrolyte separator is greater than the diameter
or area of the positive electrode by a factor of 2.
[0204] In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 0.1. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by at least a factor of
0.2. In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 0.3. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by at least a factor of
0.4. In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 0.5. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by at least a factor of
0.6. In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 0.7. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by at least a factor of
0.8. In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 0.9. In some examples, the
diameter or area of the electrolyte separator is greater than the
diameter or area of the positive electrode by at least a factor of
1. In some examples, the diameter or area of the electrolyte
separator is greater than the diameter or area of the positive
electrode by at least a factor of 2.
[0205] In some examples, the width or diameter or area of the
electrolyte separator is greater than either of the diameter or
area of the lithium metal negative electrode or of the positive
electrode. In other examples, the width or diameter of the
electrolyte separator is greater than the width or diameter of the
lithium metal negative electrode. In some other examples, the width
or diameter of the electrolyte separator is greater than the width
or diameter of the positive electrode. In some examples, the width
or diameter of the electrolyte separator is greater than both the
width or diameter of the lithium metal negative electrode and
positive electrode. In other examples, the electrolyte separator
has rounded edges which protect the bonding layer, or its
constituent components, from creeping around the electrolyte
separator. In yet other examples, the electrolyte separator has
coated edges which protect the bonding layer from creeping around
the electrolyte separator.
[0206] In some examples, the coated edges comprise a coating
selected from parylene, epoxy, polypropylene, polyethylene,
alumina, Al.sub.2O.sub.3, ZrO.sub.2, TiO.sub.2, SiO.sub.2, a binary
oxide, a lithium carbonate species, La.sub.2Zr.sub.2O.sub.7, or a
glass, wherein the glass is selected from
SiO.sub.2--B.sub.2O.sub.3, or Al.sub.2O.sub.3. In some examples,
the electrolyte separator has tapered edges which protect the
bonding layer from creeping around the electrolyte separator. In
some examples, the edges of the separator electrolyte have been
selectively treated with heat (e.g. laser beam) or chemicals (e.g.
plasma, water, acid, etc).
[0207] In some examples, set forth herein is an electrochemical
stack having an electrolyte separator which has a thickness between
about 10 and 20 .mu.m; a bonding layer which has a thickness
between about 1 .mu.m and 5 .mu.m; and a positive electrode,
exclusive of the current collector, which has a thickness between
about 5 .mu.m and 150 .mu.m.
[0208] In some examples, set forth herein is an electrochemical
stack having an electrolyte separator which has a thickness between
about 10 and 50 .mu.m; a bonding layer which has a thickness
between about 1 .mu.m and 5 .mu.m; and a positive electrode,
exclusive of the current collector, which has a thickness between
about 5 .mu.m and 150 .mu.m.
[0209] In some examples, set forth herein is an electrochemical
stack having an electrolyte separator which has a thickness between
about 10 and 100 .mu.m; a bonding layer which has a thickness
between about 1 .mu.m and 5 .mu.m; and a positive electrode,
exclusive of the current collector, which has a thickness between
about 5 .mu.m and 150 .mu.m.
[0210] In some examples, set forth herein is an electrochemical
cell having a positive electrode, a negative electrode, and an
electrolyte between the positive and negative electrode, wherein
the electrolyte includes an electrolyte separator or membrane set
forth herein.
[0211] In some examples, set forth herein is an electrochemical
cell having an electrolyte separator set forth herein, wherein the
electrochemical cell further includes a gel electrolyte.
[0212] In some examples, set forth herein is an electrochemical
cell having an electrolyte separator set forth herein, wherein the
electrochemical cell further includes a gel electrolyte between the
positive electrode active material and the electrolyte
separator.
[0213] In some examples, the gel electrolyte includes a solvent, a
lithium salt, and a polymer.
[0214] In some of these examples, the solvent is ethylene
carbonate, propylene carbonate, diethylene carbonate, methylene
carbonate, or a combination thereof.
[0215] In some of these examples, the lithium salt is LiPF.sub.6,
LiBOB, or LFTSi.
[0216] In some of these examples, the polymer is PVDF-HFP.
[0217] In some of these examples, the gel includes PVDF with the
solvent dioxolane and the salt, lithium
bis(trifluoromethane)sulfonimide (LiTFSI), at 1M concentration.
[0218] In some examples the polymer is polypropylene (PP), atactic
polypropylene (aPP), isotactive polypropylene (iPP), ethylene
propylene rubber (EPR), ethylene pentene copolymer (EPC),
polyisobutylene (PIB), styrene butadiene rubber (SBR), polyolefins,
polyethylene-co-poly-l-octene (PE-co-PO), PE-co-poly(methylene
cyclopentane) (PE-co-PMCP), poly methyl-methacrylate (and other
acrylics), acrylic, polyvinylacetacetal resin, polyvinylbutylal
resin, PVB, polyvinyl acetal resin, stereoblock polypropylenes,
polypropylene polymethylpentene copolymer, polyethylene oxide
(PEO), PEO block copolymers, silicone, or the like.
[0219] In some of these examples, the gel acetonitrile as a solvent
and a 1M concentration of a lithium salt, such as LiPF.sub.6.
[0220] In some of these examples, the gel includes a dioxolane
solvent and a 1M concentration of a Lithium salt, such as LiTFSI or
LiPF.sub.6.
[0221] In certain examples, the gel includes PVDF polymer,
dioxolane solvent and 1M concentration of LiFTSI or LiPF.sub.6. In
some other examples, the gel includes PVDF polymer, acetonitrile
(ACN) solvent and 1M concentration of LiFTSI or LiPF.sub.6. In some
of these examples, the gel has a EC:PC solvent and a 1M
concentration of a lithium salt, such as LiTFSI or LiPF.sub.6. In
some of these examples, the composite and the gel show a low
impedance of about 10 .OMEGA.cm.sup.2.
[0222] In some examples, the gel is a composite electrolyte which
includes a polymer and a ceramic composite with the polymer phase
having a finite lithium conductivity. In some examples, the polymer
is a single ion conductor (e.g., Li.sup.+). In other examples, the
polymer is a multi-ion conductor (e.g., Li.sup.+ and electrons).
The following non-limiting combinations of polymers and ceramics
may be included in the composite electrolyte. The composite
electrolyte may be selected from polyethyleneoxide (PEO)
coformulated with LiCF.sub.3SO.sub.3 and Li.sub.3N, PEO with
LiAlO.sub.2 and Li.sub.3N, PEO with LiClO.sub.4, PEO:
LiBF.sub.4--TiO.sub.2, PEO with LiBF.sub.4--ZrO.sub.2. In some of
these composites, in addition to the polymers, the composite
includes an additive selected from Li.sub.3N; Al.sub.2O.sub.3,
LiAlO.sub.3; SiO.sub.2, SiC, (PO.sub.4).sup.3-, TiO.sub.2;
ZrO.sub.2, or zeolites in small amounts. In some examples, the
additives can be present at from 0 to 95% w/w. In some examples,
the additives include Al.sub.2O.sub.3, SiO.sub.2, Li.sub.2O,
Al.sub.2O.sub.3, TiO.sub.2, P.sub.2O.sub.5,
Li.sub.1.3Ti.sub.1.7Al.sub.0.3(PO.sub.4).sub.3, or (LTAP). In some
of these composite electrolytes, the polymer present is
polyvinylidenefluoride at about 10% w/w. In some of these as
composite electrolytes, the composite includes an amount of a
solvent and a lithium salt (e.g., LiPF.sub.6). In some of these
composites, the solvent is ethyl carbonate/dimethyl carbonate
(EC/DMC) or any other solvent set forth herein. In some examples,
the composite includes a solvent useful for dissolving lithium
salts. In some of the composite electrolytes set forth herein, the
polymer serves several functions. In one instance, the polymer has
the benefit of ameliorating interface impedance growth in the solid
electrolyte even if the polymer phase conductivity is much lower
than the ceramic. In other instances, the polymer reinforces the
solid electrolyte mechanically. In some examples, this mechanical
reinforcement includes coformulating the solid electrolyte with a
compliant polymer such as poly paraphenylene terephthalamide. These
polymers can be one of a variety of forms, including a
scaffold.
[0223] In some examples, set forth is an electrochemical stack
including a positive electrode, wherein the positive electrode
includes a gel catholyte. In some examples, the gel catholyte
includes a solvent selected from the group consisting of ethylene
carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC),
methylene carbonate, and combinations thereof; a polymer selected
from the group consisting of PVDF-HFP and PAN; and a salt selected
from LiPF.sub.6, LiBOB, or LFTSi.
[0224] In some examples, including any of the foregoing, the
electrochemical stack further includes a solid electrolyte and a
bonding layer between the positive electrode and the solid
electrolyte. In some examples, the bonding layer is a phase
inversion gel electrolyte, as described herein. In certain
examples, the positive electrode includes a phase-inversion gel
catholyte. In some examples, the phase inversion gel electrolyte is
porous. In some examples, the phase inversion gel electrolyte is
10, 20, 30, 40, 50, or 60% by volume porous.
[0225] In some examples, including any of the foregoing, set forth
is a positive electrode which includes a phase inversion gel
catholyte, wherein the phase inversion gel catholyte includes a
solvent selected from the group consisting of tetrahydrofuran
(THF), ethylene carbonate (EC), propylene carbonate, dimethyl
carbonate (DMC), methylene carbonate, and combination thereof; a
polymer selected from the group consisting of PVDF-HFP and PAN; and
a non-solvent selected from toluene, acetone, and combination
thereof; and a salt selected from the group consisting of
LiPF.sub.6, LiBOB, and LFTSi.
[0226] In some examples, including any of the foregoing, set forth
is a free standing film of a gel or phase inversion gel electrolyte
having an interfacial impedance less than 10 .OMEGA.cm.sup.2 at
60.degree. C. when the film is positioned between and directly in
contact with an electrolyte separator and a positive electrode.
[0227] In some examples, including any of the foregoing, set forth
is a free standing film which includes a phase inversion gel
electrolyte, wherein the gel electrolyte comprises a lithium salt,
a polymer. The phase-inversion gel is porous and the porosity can
be tuned by, for example, the solvent(s) in the gel and the rates
at which the solvent(s) volatize away from the gel. In some
examples, the polymer is selected from the group consisting of
polyacrylonitrile (PAN), polyvinylidene fluoride
hexafluoropropylene (PVDF-HFP), or combination thereof. In certain
examples, the lithium salt is selected from LiPF.sub.6, LiBOB,
LiBF.sub.4, LiClO.sub.4, LiI, LiFSI, and LTFSI. In certain
examples, the lithium salt is LiPF.sub.6 at an average
concentration of 0.5 M to 2M. In some examples, the lithium salt is
LiTFSI at an average concentration of 0.5 M to 2M. In certain
examples, the lithium salt is present at a concentration from 0.01
M to 10 M. In some examples, the solvent is selected from the group
consisting of ethylene carbonate (EC), propylene carbonate,
dimethyl carbonate (DMC), EMC, ethyl-methyl sulfone, dinitriles,
sulfone, sulfolane, methylene carbonate, and combination thereof.
In certain examples, the solvent is a 1:1 w/w mixture of EC:PC. In
certain examples, the solvent is present at a residual amount,
wherein the residual amount of solvent is the amount remaining
after the bonding layer is dried. In certain examples, the residual
amount is the minimum amount of solvent required to solvate the
lithium salt. In certain examples, the interfacial impedance is
less than 10 .OMEGA.cm.sup.2 at 60.degree. C. when the film is
positioned between and directly in contact with an electrolyte
separator and a positive electrode.
[0228] In some examples herein, set forth is a phase inversion
bonding layer, wherein the phase inversion bonding layer has a
porosity of at least 10%.
[0229] In some examples herein, set forth is a phase inversion
bonding layer, wherein the phase inversion bonding layer has a
porosity of at least 20%. In some examples herein, set forth is a
phase inversion bonding layer, wherein the phase inversion bonding
layer has a porosity of at least 30%. In some examples herein, set
forth is a phase inversion bonding layer, wherein the phase
inversion bonding layer has a porosity of at least 40%. In some
examples herein, set forth is a phase inversion bonding layer,
wherein the phase inversion bonding layer has a porosity of at
least 50%. In some examples herein, set forth is a phase inversion
bonding layer, wherein the phase inversion bonding layer has a
porosity of at least 60%. In some examples herein, set forth is a
phase inversion bonding layer, wherein the phase inversion bonding
layer has a porosity of at least 70%.
V. Methods of Making Electrochemical Cells
[0230] In some examples, set forth herein is a method for making an
electrochemical device, including, providing a positive electrode,
providing a free standing film of a gel electrolyte. In some
examples a gel electrolyte (referred to as a bonding agent) as set
forth herein.
[0231] In some examples, the gel electrolyte includes a lithium
salt, a polymer, and a solvent. In some examples, the polymer is
selected from the group consisting of polyacrylonitrile (PAN),
polypropylene, polyethylene oxide (PEO), polymethyl methacrylate
(PMMA), polyvinyl chloride (PVC), polyvinyl pyrrolidone (PVP),
polyethylene oxide poly(allyl glycidyl ether) PEO-AGE, polyethylene
oxide 2-methoxyethoxy)ethyl glycidyl ether (PEO-MEEGE),
polyethylene oxide 2-methoxyethoxy)ethyl glycidyl poly(allyl
glycidyl ether) (PEO-MEEGE-AGE), polysiloxane, polyvinylidene
fluoride (PVDF), polyvinylidene fluoride hexafluoropropylene
(PVDF-HFP), and rubbers such as ethylene propylene (EPR), nitrile
rubber (NPR), styrene-butadiene-rubber (SBR), polybutadiene
polymer, polybutadiene rubber (PB), polyisobutadiene rubber (PM),
polyisoprene rubber (PI), polychloroprene rubber (CR),
acrylonitrile-butadiene rubber (NBR), polyethyl acrylate (PEA),
polyvinylidene fluoride (PVDF), or polyethylene (e.g., low density
linear polyethylene).
[0232] In certain examples, the polymer in the gel electrolyte is
polyacrylonitrile (PAN) or polyvinylidene fluoride
hexafluoropropylene (PVDF-HFP). In certain examples, the polymer in
the gel electrolyte is PAN, PVDF-HFP, PVDF-HFP and PAN, PMMA, PVC,
PVP, PEO, or combinations thereof. In certain examples, the lithium
salt in the gel electrolyte is a lithium salt selected from
LiPF.sub.6, LiBOB, LiTFSi, LiBF.sub.4, LiClO.sub.4, LiAsF.sub.6,
LiFSI, LiAsF.sub.6, LiClO.sub.4, LiI, or LiBF.sub.4.
[0233] In certain examples, the lithium salt in the gel electrolyte
is a lithium salt is selected from LiPF.sub.6, LiBOB, and
LFTSi.
[0234] In certain examples, the lithium salt in the gel electrolyte
is LiPF.sub.6 at a concentration of 0.5 M to 2M. In some examples,
the concentration is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3,
1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0M.
[0235] In certain examples, the lithium salt in the gel electrolyte
is LiTFSI at a concentration of 0.5 M to 2M. In some examples, the
concentration is 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4,
1.5, 1.6, 1.7, 1.8, 1.9 or 2.0M.
[0236] In certain examples, the lithium salt in the gel electrolyte
is present at a concentration from 0.01 M to 10 M. In some
examples, the concentration is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7,
0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0,
2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.3, 3.2, 3.3,
3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 2.0, 0.3, 0.2, 0.3, 0.4, 0.5, 0.6,
0.7, 0.8, 0.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9,
4.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, 6.1, 6.2,
6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, 7.2, 7.3, 7.4, 7.5,
7.6, 7.7, 7.8, 7.9, 8.0, 8.1, 8.2, 8.8, 8.4, 8.5, 8.6, 8.7, 8.8,
8.9, 9.9, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0 M.
[0237] In certain examples, the solvent is selected from ethylene
carbonate (EC), diethylene carbonate, diethyl carbonate, dimethyl
carbonate (DMC), ethyl-methyl carbonate (EMC), tetrahydrofuran
(THF), .gamma.-Butyrolactone (GBL), fluoroethylene carbonate (FEC),
fluoromethyl ethylene carbonate (FMEC), trifluoroethyl methyl
carbonate (F-EMC), fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane/1,1,2,2-Tetraflu-
oro-3-(1,1,2,2-tetrafluoroethoxy)propane (F-EPE), fluorinated
cyclic carbonate (F-AEC), propylene carbonate (PC), dioxolane,
acetonitrile (ACN), succinonitrile, adiponitrile, hexanedinitrile,
pentanedinitrile, acetophenone, isophorone, benzonitrile, dimethyl
sulfate, dimethyl sulfoxide (DMSO) ethyl-methyl carbonate, ethyl
acetate, methyl butyrate, dimethyl ether (DME), diethyl ether,
propylene carbonate, dioxolane, glutaronitrile, gamma
butyl-lactone, toluene, or combinations thereof.
[0238] In certain examples, the solvent is a 1:1 w/w mixture of
EC:PC.
[0239] In certain examples, the solvent is present as a residual
amount. In some examples, the residual amount is the amount of
solvent remaining after the bonding layer is dried. In some
examples, the residual amount is the amount of solvent remaining
after the bonding layer is spin-coated onto a substrate and dried.
In some examples, the residual amount is the minimum amount of
solvent required to solvate the lithium salt.
[0240] In yet other examples, the film lowers the interfacial
impedance between an electrolyte separator and a positive
electrode, when positioned between and directly in contact with an
electrolyte separator and a positive electrode.
[0241] Incorporated herein are methods of making gel electrolytes,
such as those in U.S. Pat. No. 5,296,318, entitled RECHARGEABLE
LITHIUM INTERCALATION BATTERY WITH HYBRID POLYMERIC
ELECTROLYTE.
One Phase Gel Electrolyte
[0242] In some examples, set forth herein is a method of making a
gel electrolyte. This method, in some examples, includes the
following steps.
[0243] In some examples, a solvent is provided and mixed with a
polymer and a lithium salt. In some examples, the solvent is
volatilized to concentrate the polymer and lithium salt.
[0244] In some examples, the solvent is selected from ethylene
carbonate (EC), diethylene carbonate, diethyl carbonate, dimethyl
carbonate (DMC), ethyl-methyl carbonate (EMC), tetrahydrofuran
(THF), .gamma.-Butyrolactone (GBL), fluoroethylene carbonate (FEC),
fluoromethyl ethylene carbonate (FMEC), trifluoroethyl methyl
carbonate (F-EMC), fluorinated
3-(1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tetrafluoropropane/1,1,2,2-Tetraflu-
oro-3-(1,1,2,2-tetrafluoroethoxy)propane (F-EPE), fluorinated
cyclic carbonate (F-AEC), propylene carbonate (PC), dioxolane,
acetonitrile (ACN), succinonitrile, adiponitrile, hexanedinitrile,
pentanedinitrile, acetophenone, isophorone, benzonitrile, dimethyl
sulfate, dimethyl sulfoxide (DMSO) ethyl-methyl carbonate, ethyl
acetate, methyl butyrate, dimethyl ether (DME), diethyl ether,
propylene carbonate, dioxolane, glutaronitrile, gamma
butyl-lactone, or combinations thereof.
[0245] In certain examples, the polymer is polyacrylonitrile (PAN)
or polyvinylidene fluoride hexafluoropropylene (PVDF-HFP). In
certain examples, the polymer in the gel electrolyte is PAN,
PVDF-HFP, PVDF-HFP and PAN, PMMA, PVC, PVP, PEO, or combinations
thereof. In certain examples, the lithium salt in the gel
electrolyte is a lithium salt is selected from LiPF.sub.6, LiBOB,
LiTFSi, LiBF.sub.4, LiClO.sub.4, LiAsF.sub.6, LiFSI, LiAsF.sub.6,
LiClO.sub.4, LiI, or LiBF.sub.4. In certain examples, several
lithium salts may be present simultaneously in different
concentrations.
Phase Inversion Gel Electrolyte
[0246] In some examples, set forth herein is a method of making a
phase inversion gel. This method, in some examples, includes the
following steps.
[0247] In some examples, a polymer is dissolved in a solvent which
dissolves the polymer. For example, when the polymer is PVDF-HFP,
the solvent may be tetrahydrofuran (THF). In some examples, the
ratio of PVDF-HFP:THF is between 0.01 and 10. In some examples, the
ratio of PVDF-HFP:THF is 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07,
0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0. 6, 0.7, 0.8, 0.9, 1, 2, 3,
4, 5, 6, 7, 8, 9, or 10. In some examples, the polymer and solvent
are mixed to form a mixture. In some examples, this mixture is
heated. In certain examples, the mixture is heated to volatilize
the solvent. In some examples, the mixture is stirred. In some
examples, the stirring is at 100 revolutions per minute (RPM). In
certain examples, a non-solvent is then added. In some of these
examples, the non-solvent is toluene when the polymer is PVDF-HFP.
In some examples, non-solvent is added to that the weight of the
non-solvent with respect to the weight of the PVDF-HFP is 1, 2, 3,
4, 5, 6, 7, 8, 9, or 10 times. For example, the (weight of the
non-solvent)/(weight of the polymer) is 1, 2, 3, 4, 5, 6, 7, 8, 9,
or 10. In some examples, the mixture with the non-solvent is heated
until the solvent evaporates or is reduced to a residual amount. In
some examples, the heated mixture is spin-cast onto a substrate to
form a film. In some examples, the rate of spin for the spin-coater
determines the thickness of the spin-cast film. In some examples,
the spin-cast film can be released from the substrate on which it
was cast to form a free standing film.
EXAMPLES
Example 1--Making an Electrochemical Stack Having a Bonding
Layer
[0248] In this example, a free standing gel electrolyte film was
first prepared.
[0249] A blend of ethylene carbonate (EC) and propylene carbonate
(PC) solvents was prepared in a 1:1 w/w ratio. The lithium salt
lithium hexafluorophosphate was added to this mixture to achieve a
1M solution. To form the gel solution, 0.8 grams of a PVDF-HFP
polymer (Kynar 2801) was mixed 2.8 grams of the lithium
hexafluorophosphate solution and 8.5 grams of a solvent, THF
(Tetrahydrofuran). The solution was cast via doctor blade onto a
glass substrate inside a glove box. The film was allowed to dry in
the glove box for 4 hours. The dry film thickness was 45 .mu.m.
This dry film was used as the gel electrolyte 103 below.
[0250] As shown in FIG. 1, two electrochemical stacks were
prepared. The layers were pressed together in the actual
electrochemical stack, but in FIG. 1 the layers are separated for
illustrative purposes.
[0251] In one example, 100, the electrochemical stack, 100,
included a positive electrode, 102, having a Ni--Co--Al positive
electrode active material, with C65 carbon and a gel catholyte. The
gel catholyte included an 80:20 w/w mixture of PVDF-HFP in EC:PC
with 1M LiPF.sub.6. This stack also included a solid
lithium-stuffed garnet, 104, Li.sub.7La.sub.3Zr.sub.2O.sub.12 0.35
Al.sub.2O.sub.3, 50 .mu.m thick electrolyte separator. Laminated to
the bottom of, 104, was lithium metal, 105.
[0252] In another example, 101, the electrochemical stack, 101,
includes a positive electrode, 102, having an Ni--Co--Al positive
electrode active material, with C65 carbon and a gel catholyte. The
gel catholyte included an 80:20 w/w mixture of PVDF-HFP in EC:PC
with 1M LiPF.sub.6. This stack also included a solid
lithium-stuffed garnet, 104,
Li.sub.7La.sub.3Zr.sub.2O.sub.12Al.sub.2O.sub.3, 50 .mu.m thick
electrolyte separator. Evaporated to the bottom of, 104, was
lithium metal, 105. Positioned in between and in direct contact
with layers, 102 and 104, was a gel electrolyte, 103. Gel
electrolyte/bonding layer, 103, was prepared as noted above.
[0253] The combination of a gel and a solid lithium-stuffed garnet
was surprisingly stable. Organic solvents typically react with
garnet. However, the gel used in this example did not. Typically
carbonates react to produce CO.sub.2 at high V or high T, and
CO.sub.2 may react with garnet. This results in an increase in
impedance due to the resistive layer formed by the reaction of
CO.sub.2 and garnet. This effect is exacerbated at higher voltages.
For this reason, it is not typical to combine carbonate
electrolytes with a garnet. However, the gel used in this example
did not appreciably react with garnet as demonstrated by the low
impedance observed, even when cycled to high voltages. This was a
surprising effect since one might have expected that the organic
solvent in the gel would have reacted with the solid
lithium-stuffed garnet just as an organic solvent, absent a gel,
would have been expected to react. The lack of a reaction between
the gel and the lithium-stuffed garnet was possibly due to the slow
diffusion of the solvent and salts in the gel. Without being bound
by any particular theory, it is also possible that the gel layer
inhibits diffusion of CO.sub.2 to the garnet interface. If the
bonding layer is an electronic insulator, it protects the separator
electrolyte from the voltage of the cathode and any undesirable
side-reactions that may result due to the high voltage instability
of the separator. As a separator used in a lithium metal anode
battery must be stable to lithium, there are few candidate
separator materials that are simultaneously stable to the high
voltage of the positive electrode and the low voltage of the
negative electrode. The gel layer may thus enable a larger set of
separator materials.
Example 2--Testing an Electrochemical Stack Having a Bonding
Layer
[0254] Both stacks, 100 and 101, from Example 1 were analyzed to
see their voltage response as a function of time for a pulsed
current electrochemical test. An OCV step was applied until time
approximately 2000 s in the graph, then a current was applied of
0.1 mA/cm.sup.2 until about time 5600 s, when the OCV was monitored
under no applied current. The voltage response to the current step
is monitored and shown in FIG. 2. The electrochemical stack, 100,
was observed to have an immediate rise in impedance. This indicates
too high of an interfacial ASR between the layers in the
electrochemical stack. This Example demonstrates that pressing a
cathode onto a garnet surface is ineffective and results in a very
large impedance. However, when a gel electrolyte is used, and
placed between and in direct contact with solid electrolyte and the
positive electrode, the interfacial impedance is reduced.
[0255] FIG. 3 shows a GITT test of pulsed current throughout a full
charge and discharge cycle for one cell with a bonding layer when
cycled between 2.7-4.2V. Full capacity can be obtained from the
cell with a relatively low resistance.
Example 3--Making a Spin Coated Gel Bonding Layer
[0256] A blend of ethylene carbonate (EC) and propylene carbonate
(PC) solvents was prepared in a 1:1 w/w ratio. The lithium salt,
LiPF.sub.6, was added to this mixture to achieve a 1M solution. PAN
polymer was mixed with the solution in a measured volume ratio PAN
to EC:PC. The solution was spin-cast using a Laurel Technologies,
Spincoater for up to 60 seconds to form a film. By varying the
spin-cast RPM(s), thicker or thinner free standing films were
prepared. The film was allowed to dry at room temperature on a
garnet substrate for twenty-four hours. FIG. 4 shows the thickness
of a PAN-containing film, which is as a function of the spin-cast
RPM. The scale bar in FIG. 4 is 5 .mu.m. Higher RPM results in
thinner films. FIG. 5 shows a 47.4% PAN gel electrolyte which was
spin-cast at 2000 RPM. The gel electrolyte, 501, is positioned on
top of the garnet separator, 502. The scale bar in FIG. 5 is 100
.mu.m.
Example 4--Testing Individual Electrochemical Layers with Spin
Coated Gel Bonding Layer
[0257] Determination of the interfacial resistance between a
bonding layer and a garnet electrolyte requires measurement of a
full cell resistance and subtraction of all other resistance
components. The following experiments are used to determine the
resistance of each layer and interface in a full cell so as to
enable calculation of the interfacial resistance between a gel and
a garnet separator (ASR.sub.B-G). As shown in FIG. 6, an
electrochemical stack was provided having Li metal 603, a solid
lithium-stuffed garnet, 602,
Li.sub.7La.sub.3Zr.sub.2O.sub.12Al.sub.2O.sub.3, 50 .mu.m thick
film, and a lithium metal electrode, 601. This configuration is
referred to a symmetric cell Li|garnet|Li cell.
[0258] FIG. 7 shows a stack consisting of
Li|Garnet|scGel|fsGel|Li-foil which was constructed and measured.
Here, scGel refers to the spin-coat prepared gel electrolyte layer,
705 and fsGel refers to the doctor-blade coated free standing gel
electrolyte layer, 702. Based on the aforementioned results, the
ASR in a stack Li|Garnet|scGel|fsGel|Li-foil=ASR.sub.tot was
measured.
[0259] By determining, the contributions from all other components
in the structure Li|Garnet|scGel|fsGel|Li-foil (FIGS. 6 and 7), the
resistance of the scGel|Garnet interface was calculated according
to
ASR.sub.I/F,SSE-.sub.scGel=ASR.sub.tot-ASR.sub.fsGel,bulk-ASR.sub.SSE,bul-
k-ASR.sub.fsGel-Li-ASR.sub.I/F SSE-Li. In FIG. 7, layer 701 is a
Li-foil. Layer 703 is the solid electrolyte separator made of
Li.sub.7La.sub.3Zr.sub.2O.sub.120.35Al.sub.2O.sub.3. Layer 704 is
Li metal. This calculation assumes that the fsGel-scGel ASR is
negligible. The ASR of the garnet bulk was found to be 10
.OMEGA.cm.sup.2, the ASR of the garnet-Li interface was 3.+-.2
.OMEGA.cm.sup.2.
[0260] In total, three gel electrolytes were prepared with the
following compositions: (A) 30% w/w PVDF-HFP in EC:PC; (B) 50% w/w
PVDF-HFP in EC:PC; and (C) 18.4% w/w PAN in EC:PC.
[0261] The associated ASR of the films at 60.degree. C. is shown as
a function of spin-coating RPM in FIG. 8. In the case B. PVDF-HFP
(50%) where the spin speed was 1,500 RPM and the spin coated gel
thickness was 5.5 .mu.m thick the total ASR for the Li-garnet-gel
was 65.+-.12 .OMEGA.cm.sup.2. The ASR of the garnet-gel interface
was found to be as low as 22 .OMEGA.cm.sup.2 at 60.degree. C. in
this configuration. In full cells, the ASR of the garnet-gel
interface was found to be between 1 and 5 .OMEGA.cm.sup.2 at
45.degree. C. This ASR is surprisingly low compared to the cells
from Example 1, where a cell with no bonding layer was too
resistive to be charged. It is surprising due to the fact that an
additional resistive layer may be introduced into the cell and the
total cell resistance decreases.
Example 5--Comparing Gel Bonding Layers with Other Materials
[0262] A garnet pellet is used to separate two isolated chambers
full of liquid electrolyte of EC:PC (1M LiPF.sub.6). A Li foil is
held in each chamber and a current is passed which causes
dissolution of lithium on one electrode and plating of lithium on
the other electrode. To pass current, lithium ions must travel
through the liquid in the first chamber, pass through the garnet
pellet, and finally through the liquid in the other chamber to
reach the lithium foil. The voltage drop across the entire cell is
measured throughout this process. The impedance of the
liquid-garnet interface and be deduced by knowledge of the other
sources of voltage drop in the system including the liquid
impedance itself and the impedance of the pellet. It was found that
the impedance of the Garnet-Liquid electrolyte (labeled "Liquid" in
FIG. 9) interface was on the order of 5,000 .noteq.cm.sup.2. These
results show that a liquid reacts with the Li metal anode and
results in a high ASR. The liquid was observed to react with Li
metal to form a high impedance layer, such as a lithium carbonate
layer.
[0263] The garnet was also paired with a solid (a
lithium-phosphorus-sulfide electrolyte) or polymer bonding layer
(PEO with LiClO.sub.4) in an electrochemical stack with the same
configuration as FIG. 7. The garnet oxide interfacial impedance was
also rather high, e.g., 60-202 .OMEGA.cm.sup.2 at 60.degree. C., as
shown in FIG. 9, to the detriment of any device which includes this
pair. These results show that gels, as compared to liquids, solids,
or polymers pair with garnet electrolyte separators to protect the
Li metal negative electrode and provide a low ASR interface.
[0264] Gel electrolytes usually have a lower ionic conductivity
than a liquid electrolyte. Thus, by pairing a gel electrolyte with
a garnet, as opposed to a liquid electrolyte, one would expect that
the total ASR would be higher for the gel-electrolyte-garnet as
compared to the liquid-electrolyte-garnet. However, the results
herein demonstrate surprisingly that the gel-electrolyte-garnet has
lower ASR, than the corresponding liquid-electrolyte-garnet.
[0265] As shown in FIG. 9, the gel electrolyte resulted in a
surprisingly lower interfacial ASR than either of the liquid,
polymer, or solid electrolytes. One interpretation of the
surprisingly lower interfacial ASR of a gel as compared to a liquid
is that a gel enforces wetting of the interface, whereas many
liquids do not easily wet the separator interface. A wettability
measurement is shown in FIG. 14, showing a large contact angle
between the separator and electrolyte.
Example 6--Making a Phase Inversion Gel Bonding Layer
[0266] PVDF-HFP polymer was dissolved in Tetrahydrofuran (THF) in a
ratio of PVDF-HFP:THF=0.05:1 heated on a hot-plate to 80.degree. C.
and stirred at 100 rpm till the polymer dissolves. Then the
non-solvent toluene was added drop-wise to the solution in a ratio
of such that the weight of toluene added is 3.5 times PVDF-HFP. The
solution was spin-cast using a spin-coater from Laurel Technologies
up to 60 seconds. The spin-coater RPM can be adjusted to obtain gel
films of different thicknesses. Higher RPM results in thinner
films. FIG. 10 shows the plan view and FIG. 11 shows a
cross-section of the phase-inversion gel (thickness 1 micron) spin
coated on Si wafer, at a speed of 1200 rpm. In FIG. 10, the porous
space is shown in black and labeled as 1001. The polymer matrix
(i.e., network) is shown in gray and labeled as 1002. The full-cell
stack cross-section is as shown in FIG. 11. In FIG. 11, the
phase-inversion gel electrolyte is labeled as 1101 and is
positioned on top of a silicon substrate. The silicon substrate is
labeled as 1102.
Example 7--Testing the Individual Electrochemical Layer After Phase
Inversion Gel Bonding
[0267] The conductivity of the gel was evaluated by creating a
"sandwich" of a thick, free standing version of the gel (100
microns thick) soaked in electrolyte EC:EMC with 1M LiPF.sub.6, in
between two stainless steel spacers and assembling this sandwich in
a coin cell. At 45.degree. C., the resistance of this stack is
2-2.5.OMEGA., amounting to a total ASR of 4 .OMEGA.-cm.sup.2. The
bulk resistance of a 1 micron thick gel is expected to be 100 times
less, accounting for a small impedance contribution in a full
stack.
Example 8--Testing the Bonding Layer After Phase Inversion Gel
Bonding in a Stack
[0268] The spin-coated gel on garnet was assembled against another
spin-coated gel on garnet to create a sandwich with two spin coated
gels in between two garnet pellets. The pellets are coated with 2
or 30 .mu.m evaporated lithium on the other side. This stack was
assembled in a coin cell stack such that the gel is under the same
pressure as it would be under a full cell stack. Electrochemical
Impedance Spectroscopy response of this stack is shown in FIG.
13.
[0269] There were two parallel resistive-capacitative (RC)
responses observed in this system: the first corresponds to bulk
impedance of the two garnet pellets, marked by R1 in FIG. 13. The
second semi-circle corresponds to the resistive capacitative (RC)
response of two garnet-gel interfaces. The impedance corresponding
to the x-intercept of these semi-circles was interpreted as
R.sub.bulk,garnet and R.sub.garnet-gel interface respectively. The
area specific resistance of the interface was determined by
dividing R2 by two (since there are two interfaces) and multiplying
with the electrode area (0.636 cm.sup.2). The interfacial impedance
between gel and garnet was found to be less than 2 .OMEGA.cm.sup.2
at 45.degree. C. and less than 5 .OMEGA.cm.sup.2 at 20.degree.
C.
[0270] The foregoing description of the embodiments of the
disclosure has been presented for the purpose of illustration; it
is not intended to be exhaustive or to limit the claims to the
precise forms disclosed. Persons skilled in the relevant art can
appreciate that many modifications and variations are possible in
light of the above disclosure.
[0271] The language used in the specification has been principally
selected for readability and instructional purposes, and it may not
have been selected to delineate or circumscribe the inventive
subject matter. It is therefore intended that the scope of the
disclosure be limited not by this detailed description, but rather
by any claims that issue on an application based hereon.
Accordingly, the disclosure of the embodiments is intended to be
illustrative, but not limiting, of the scope of the disclosure,
which is set forth in the following claims.
* * * * *