U.S. patent application number 14/932656 was filed with the patent office on 2016-02-25 for lithium electrode for lithium metal battery and method of manufacturing the lithium electrode.
The applicant listed for this patent is Hyundai Motor Company. Invention is credited to Ki Chun Lee, Yoon Ji Lee, Jun Ki Rhee, Hee Yeon Ryu, Hee Jin Woo.
Application Number | 20160056501 14/932656 |
Document ID | / |
Family ID | 49491743 |
Filed Date | 2016-02-25 |
United States Patent
Application |
20160056501 |
Kind Code |
A1 |
Ryu; Hee Yeon ; et
al. |
February 25, 2016 |
LITHIUM ELECTRODE FOR LITHIUM METAL BATTERY AND METHOD OF
MANUFACTURING THE LITHIUM ELECTRODE
Abstract
Disclosed are a lithium electrode for a lithium metal battery,
which uses a solid high-ionic conductor having a three-dimensional
(3D) porous structure, wherein a lithium metal or lithium alloy is
filled into each pore and dispersed, and a method for manufacturing
the lithium electrode. By applying a solid high-ionic conductor
having a 3D porous structure, an ion conduction path is secured in
the lithium electrode using the solid high-ionic conductor instead
of a conventional liquid electrolyte, electrical-chemical
reactivity in charging and discharging are further improved, and
shelf life and high rate capability are enhanced.
Inventors: |
Ryu; Hee Yeon; (Uiwang,
KR) ; Lee; Yoon Ji; (Bucheon, KR) ; Woo; Hee
Jin; (Yongin, KR) ; Rhee; Jun Ki; (Suwon,
KR) ; Lee; Ki Chun; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hyundai Motor Company |
Seoul |
|
KR |
|
|
Family ID: |
49491743 |
Appl. No.: |
14/932656 |
Filed: |
November 4, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13561464 |
Jul 30, 2012 |
9190658 |
|
|
14932656 |
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Current U.S.
Class: |
429/322 ;
429/231.95 |
Current CPC
Class: |
H01M 10/052 20130101;
H01M 4/62 20130101; Y02T 10/70 20130101; H01M 2300/0068 20130101;
H01M 4/1395 20130101; H01M 4/382 20130101; Y02P 70/50 20151101;
Y10T 29/49115 20150115; H01M 4/80 20130101; H01M 10/4235 20130101;
Y02E 60/10 20130101; H01M 4/38 20130101; H01M 4/134 20130101; H01M
4/661 20130101; H01M 10/0562 20130101; H01M 2004/027 20130101 |
International
Class: |
H01M 10/0562 20060101
H01M010/0562; H01M 4/62 20060101 H01M004/62; H01M 10/052 20060101
H01M010/052; H01M 4/38 20060101 H01M004/38 |
Foreign Application Data
Date |
Code |
Application Number |
May 2, 2012 |
KR |
10-2012-0046330 |
Claims
1. A lithium electrode for a lithium metal battery, the lithium
electrode comprising: a solid high-ionic conductor having a 3D
porous structure; a lithium metal or lithium alloy filled in a
plurality of open pores of the 3D porous structure; and a collector
coupled onto a surface of the solid high-ionic conductor.
2. The lithium electrode of claim 1, wherein the lithium metal or
lithium alloy is filled in each open pore of the 3D porous
structure.
3. The lithium electrode of claim 1, further comprising a reaction
activating material coated onto an interface between the solid
high-ionic conductor and the lithium metal to improve interfacial
reaction.
4. The lithium electrode of claim 3, wherein the reaction
activating material is selected from the group consisting of
aluminium (Al), indium (In) metal, Al.sub.2O.sub.3, ZrO.sub.2,
ceramic materials, and combinations thereof.
5-7. (canceled)
8. The method of claim 5, wherein the solid high-ionic conductor is
manufactured with any one or more materials selected from the group
consisting of LiSICON (.gamma.-Li.sub.3PO.sub.4 derivative),
Thio-LiSICON (Li.sub.3.25Ge.sub.0.25P.sub.0.75S.sub.4 derivative),
NaSiCON (NaZr.sub.2P.sub.3O.sub.12 derivative), Perovskite
(La.sub.2/3Li1.sub.1/3TiO.sub.3 derivative), Garnet
(Li.sub.5La.sub.3M.sub.2O.sub.12, M=Ta,Nb derivative), LiPON,
LiPOS, LiSON, and LiSIPON.
9-13. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims under 35 U.S.C. .sctn.119(a) the
benefit of Korean Patent Application No. 10-2012-0046330 filed on
May 2, 2012, the entire contents of which are incorporated herein
by reference.
BACKGROUND
[0002] (a) Technical Field
[0003] The present invention relates to a lithium electrode for a
lithium metal battery and a method of manufacturing the lithium
electrode. More particularly, the present invention relates to a
lithium electrode for a lithium metal battery, which uses a solid
high-ionic conductor having a three-dimensional ("3D") porous
structure, and a method for manufacturing the lithium
electrode.
[0004] (b) Background Art
[0005] Due to the high ionic conductivity of a solid electrolyte
even at room temperature, much research has been focused on the
development of a lithium metal battery which can utilize a solid
electrolyte instead of a liquid electrolyte. However, when a solid
electrolyte is applied to an electrode in the form of powder, the
interfacial resistance between an electrode active material and the
solid electrolyte increases. Therefore, there is a need to reduce
the interfacial resistance between the electrode active material
and the solid electrolyte, which is used in an electrode such as a
positive electrode ("cathode") of a lithium ionic battery. In an
attempt to reduce the resistance and improve performance, an
oxide-based film has been formed on the surface of the electrode
active material.
[0006] However, particularly in the case of a lithium metal
battery, in which lithium metal is used as a negative electrode
("anode"), securing an ion conduction path in the lithium electrode
continues to be an issue.
SUMMARY OF THE DISCLOSURE
[0007] The present invention has been made in an effort to solve
the above-described problems associated with prior art, and
provides a lithium electrode for a lithium metal battery and a
method of manufacturing the lithium electrode. In particular,
rather than a conventional liquid electrolyte, a solid high-ionic
conductor structure having a 3D porous structure is used for
securing an ion conduction path, and lithium metal or lithium alloy
is filled and dispersed in each pore. As such, shelf life of the
lithium metal battery is increased and an ion conduction path of
lithium is secured. As used herein, the terms "fill", "filling",
"filled" and the like, when used to refer to the lithium metal or
lithium alloy in the pores, refer not only to completely filling
the pores, but also refer to partially filling the pores to any
extent.
[0008] In one aspect, the present invention provides a lithium
electrode for a lithium metal battery, the lithium electrode
including a solid high-ionic conductor having a 3D porous
structure, a lithium metal or lithium alloy filled in each open
pore of the 3D porous structure, and a collector coupled onto the
surface of the solid high-ionic conductor.
[0009] According to various embodiments, a reaction activating
material may be coated onto an interface between the solid
high-ionic conductor and the lithium metal to improve interfacial
reaction. The reaction activating material may in some embodiments
be selected from the group consisting of aluminium (Al), indium
(In) metal, Al.sub.2O.sub.3, ZrO.sub.2, ceramic materials and
combinations thereof.
[0010] In another aspect, the present invention provides a method
of manufacturing a lithium electrode for a lithium metal battery,
the method including manufacturing a solid high-ionic conductor as
a 3D porous structure, filling a lithium metal or lithium alloy in
each open pore of the 3D porous structure, and coupling a collector
onto a surface of the solid high-ionic conductor having the lithium
metal or lithium alloy filled into each pore.
[0011] According to various embodiments, an average pore size of
the solid high-ionic conductor is in a range of about 0.01-50
.mu.m, and its porosity is in a range of about 30-90%.
[0012] According to various embodiments, the solid high-ionic
conductor is manufactured from one or more materials selected from
the group consisting of LiSICON (.gamma.-Li.sub.3PO.sub.4
derivative), Thio-LiSICON (Li.sub.3.25Ge0.25P0.75S4 derivative),
NaSiCON (NaZr.sub.2P.sub.3O.sub.12 derivative), Perovskite
(La.sub.2/3Li.sub.1/3TiO.sub.3 derivative), Garnet
(Li.sub.5La.sub.3M.sub.2O.sub.12, M=Ta,Nb derivative), LiPON,
LiPOS, LiSON, and LiSIPON.
[0013] According to various embodiments, the solid high-ionic
conductor is manufactured as a 3D porous structure by using any
suitable method. For example, the 3D porous structure may be formed
by using a colloidal crystal template method, a carbon template
method, a freeze casting method, an aerogel synthesis method, or a
tape casting method.
[0014] According to various embodiments, the lithium metal or
lithium alloy is filled into each pore of the solid high-ionic
conductor by using any suitable method. For example, the lithium
metal or lithium alloy is filled into each pore by using a melting
method which melts lithium or lithium of the lithium alloy and
fills the lithium in a pressurizing or depressurizing manner, a
thin film coating method which uses metal deposition (e.g. chemical
vapor deposition (CVD) and physical vapor deposition (PVD)), a
powder particle paste filing method which fills lithium powder in a
paste form, and an extracting method which inserts lithium ion
liquid and extracts the lithium ion liquid as metal.
[0015] According to various embodiments, the method may further
include coating a reaction activating material onto an interface
between the solid high-ionic conductor and the lithium metal so as
to improve interfacial reaction. Suitable reaction activating
materials can, for example, be selected from the group consisting
of aluminium (Al), indium (In) metal, Al.sub.2O.sub.3, ZrO.sub.2,
ceramic materials and mixtures thereof.
[0016] Other aspects and preferred embodiments of the invention are
discussed infra.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The above and other features of the present invention will
now be described in detail with reference to exemplary embodiments
thereof illustrated the accompanying drawings which are given
hereinbelow by way of illustration only, and thus are not
limitative of the present invention, and wherein:
[0018] FIG. 1 is a diagram showing a lithium electrode for a
lithium metal battery according to the present invention; and
[0019] FIG. 2 is another diagram showing a lithium electrode for a
lithium metal battery according to the present invention.
[0020] It should be understood that the appended drawings are not
necessarily to scale, presenting a somewhat simplified
representation of various preferred features illustrative of the
basic principles of the invention. The specific design features of
the present invention as disclosed herein, including, for example,
specific dimensions, orientations, locations, and shapes will be
determined in part by the particular intended application and use
environment.
[0021] In the figures, reference numbers refer to the same or
equivalent parts of the present invention throughout the several
figures of the drawing.
DETAILED DESCRIPTION
[0022] Hereinafter, exemplary embodiments of the present invention
will be described in detail with reference to the accompanying
drawings to allow those of ordinary skill in the art to easily
carry out the present invention. While the invention will be
described in conjunction with the exemplary embodiments, it will be
understood that present description is not intended to limit the
invention to the exemplary embodiments. On the contrary, the
invention is intended to cover not only the exemplary embodiments,
but also various alternatives, modifications, equivalents and other
embodiments, which may be included within the spirit and scope of
the invention as defined by the appended claims.
[0023] It is understood that the term "vehicle" or "vehicular" or
other similar term as used herein is inclusive of motor vehicles in
general such as passenger automobiles including sports utility
vehicles (SUV), buses, trucks, various commercial vehicles,
watercraft including a variety of boats and ships, aircraft, and
the like, and includes hybrid vehicles, electric vehicles, plug-in
hybrid electric vehicles, hydrogen-powered vehicles and other
alternative fuel vehicles (e.g., fuels derived from resources other
than petroleum). As referred to herein, a hybrid vehicle is a
vehicle that has two or more sources of power, for example both
gasoline-powered and electric-powered vehicles.
[0024] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof. As
used herein, the term "and/or" includes any and all combinations of
one or more of the associated listed items.
[0025] Unless specifically stated or obvious from context, as used
herein, the term "about" is understood as within a range of normal
tolerance in the art, for example within 2 standard deviations of
the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%,
5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated
value. Unless otherwise clear from the context, all numerical
values provided herein are modified by the term "about."
[0026] Ranges provided herein are understood to be shorthand for
all of the values within the range. For example, a range of 1 to 50
is understood to include any number, combination of numbers, or
sub-range from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,
44, 45, 46, 47, 48, 49, or 50, as well as all intervening decimal
values between the aforementioned integers such as, for example,
1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. With respect to
sub-ranges, "nested sub-ranges" that extend from either end point
of the range are specifically contemplated. For example, a nested
sub-range of an exemplary range of 1 to 50 may comprise 1 to 10, 1
to 20, 1 to 30, and 1 to 40 in one direction, or 50 to 40, 50 to
30, 50 to 20, and 50 to 10 in the other direction.
[0027] The present invention provides a solid high-ionic conductive
lithium electrode, particularly an anode.
[0028] in a new form, in which a solid high-ionic conductor is used
in place of a conventional liquid electrolyte. In particular, the
solid high-ionic conductor has a 3D porous structure, wherein
lithium or lithium alloy is filled in the pores of the 3D porous
solid high-ionic conductor to thereby provide a lithium metal
battery with increased shelf life, improve output characteristics,
and secure ionic conductivity of lithium in charging and
discharging.
[0029] FIGS. 1 and 2 show exemplary structures of a porous solid
high-ionic conductor for manufacturing a lithium electrode,
particularly an anode, for a lithium metal battery according to the
present invention.
[0030] As shown, each pore is formed as an open pore. While it is,
of course, possible to form a portion of the pores as open pores
and a portion as closed pores, it is preferable that all pores are
formed as open pores for subsequent filling with lithium. The shape
of each pore is not particularly limited, and may be spherical as
shown in FIG. 1, isotropic as shown in FIG. 2, or any other variety
of shapes. The size of each pore can be set to be an optimal size
according to the thickness of the lithium electrode. For example,
in some embodiments the average pore size is preferably in a range
of about 0.01-50 .mu.m which can maximize interfacial reactivity
between lithium and the high-ionic conductor in the pore. The set
pore size can be based on a lithium usage rate of 25-50% taking
into consideration contact area and reactivity between lithium and
the solid high-ionic conductor.
[0031] The porosity of the solid high-ionic conductor may also be
set so as to take into account minimum application of the
high-ionic conductor for securing ion conductivity while using
lithium to a maximum amount, and also so as to provide mechanical
stability based on the application. For example, according to a
preferred embodiment, the porosity is set in a range of about
30-90%.
[0032] As shown in the figures, the solid high-ionic conductor
having the 3D porous structure can be manufactured as an ordered
pore structure (i.e., uniformly distributed pores throughout) so as
to secure a desired ion conductivity. However, the 3D porous
structure may also be designed as an irregular and non-ordered
porous structure (i.e., a structure having irregular, non-uniform
pore arrangement) which can provide increased porosity for filling
with lithium and, thus, may maximize the amount of lithium metal
which can be used.
[0033] According to embodiments of the present invention, the solid
high-ionic conductor can be formed from a variety of suitable
materials and, for example, may include a sulfide-based structure
and an oxide-based structure, more specifically, a crystalline
structure and an amorphous structure such as LiSICON
(.gamma.-Li.sub.3PO.sub.4 derivative), Thio-LiSICON
(Li.sub.3.25Ge.sub.0.25P.sub.0.75S.sub.4 derivative), NaSiCON
(NaZr.sub.2P.sub.3O.sub.12 derivative), Perovskite
(La.sub.2/3Li1.sub.1/3TiO.sub.3 derivative), Garnet
(Li.sub.5La.sub.3M.sub.2O.sub.12, M=Ta,Nb derivative), LiPON,
LiPOS, LiSON, and LiSIPON.
[0034] Further, a variety of methods can be used to manufacture the
solid high-ionic conductor as a 3D porous structure. For example, a
colloidal crystal template method, a carbon template method, a
freeze casting method an aerogel synthesis method, a tape casting
method, or the like may suitably be used.
[0035] The colloidal crystal template method and the carbon
template method are particularly useful to facilitate ordering and
size adjustment of each pore of the 3D porous structure. The freeze
casting method allows for growth of the conductor in a rod form and
further facilitates ordering of pores between rods. The aerogel
synthesis method may be used to provide high porosity, such as
porosity of 95% or higher, with each pore being formed in a nano
size.
[0036] Any variety of methods can be suitably used to fill lithium
in each pore of the 3D porous structure of the solid high-ionic
conductor. For example, a lithium or lithium alloy melting method,
a thin-film coating method, or a powder particle paste filling
method may be used.
[0037] These filling methods are known and can be carried out by
the present invention in accordance with the known procedures. For
example, the melting method is generally carried out by melting
lithium or lithium of lithium alloy and filling the melted lithium
in a pressurizing or depressurizing manner. The thin film coating
method uses metal deposition, such as chemical vapor deposition
(CVD) and physical vapor deposition (PVD), to fill the lithium. The
powder particle paste filing method fills lithium powder in a paste
form. The extracting method inserts lithium ion liquid in the pores
and extracts it as metal. Further, a reaction activating material
(e.g. Al, indium (In) metal, Al.sub.2O.sub.3, ZrO.sub.2, ceramic,
etc.) may be coated on the interface (interface between the solid
high-ionic conductor and lithium metal, particularly the inner
surface forming the pores) in the form of an ultrathin film to
improve interfacial reaction.
[0038] After lithium metal is filled into each pore of the 3D
porous structure, a metal collector is coupled onto the surface of
the solid high-ionic conductor. The collector can be coupled
through any suitable method, such as through thin-film coating or
using a binder. The metal collector may also be coupled prior to
lithium metal filling. The collector is preferably formed with any
material having electric conductivity, such as metals (copper,
nickel, etc.) and carbons.
[0039] The present invention is preferably carried out so as to
uniformly fill lithium or lithium alloy in each pore of the 3D
porous solid high-ionic conductor. Of course, it is also possible
to fill only a portion of the pores of the 3D porous solid
high-ionic conductor, and/or to fill the pores in a non-uniform
manner. The pores can be filled by any suitable method, such as the
previously described melting method, thin film coating method,
powder particle paste filing method, and extracting method, to thus
manufacture the lithium electrode. The present invention secures an
ion conduction path in the lithium electrode, improves
electrical-chemical reactivity in charging and discharging, and
further increases shelf life and high rate capability.
[0040] Hereinafter, the following Examples are intended to
illustrate the present invention without limiting its scope.
Example 1
[0041] La.sub.2O.sub.3 (powder)+Li.sub.2CO.sub.3 (powder)+TiO.sub.3
(powder) were mixed, ground and then sintered at high temperature
of 1350.degree. C. to obtain an oxide-based high-ionic conductor
(La.sub.2/3Li.sub.1/3TiO.sub.3). The powder was prepared with an
average particle size of 500 nm or less.
[0042] Dispersed polystyrene beads a few micrometers in size were
provided, mixed with ethanol (i.e., a dispersion solvent) and an
oxide-based high-ionic conductor, dispersed by ultrasonication and
dried. Then, polystyrene was removed therefrom using methylene
dichloride, followed by heat treatment at a high temperature (a
temperature of 300.degree. C.) to obtain a 3D porous structure
(10.times.10.times.0.7 mm) having open pores, in which the porosity
was 70% and a average pore size was about 1.7 .mu.m.
[0043] Then Al.sub.2O.sub.3 was coated on the interface in the form
of an ultrathin film by PVD (Physical Vapour Deposition) with
substrate temperature at 700.degree. C. Even though there was a
thickness gradient of a 3D porous structure, the thickness of the
Al.sub.2O.sub.3 coating was less than 10 nm from TEM investigation.
Because the solid high-ionic conductor (3D porous structure) reacts
with lithium, the reaction is prevented by adding the
Al.sub.2O.sub.3 coating step with nano-size thickness between
interfaces.
[0044] Next, a depressurization-induced method was carried out to
fill the pores in the 3D porous structure. First, the manufactured
3D porous structure was mounted on a lithium melting device
installed in a chamber in an argon atmosphere, lithium metal was
melted at 300.degree. C., and the melted lithium metal was filled
in the 3D porous structure.
[0045] Finally, copper was sputtering-coated on the surface of the
thus formed high-ionic conductor having the lithium-filled 3D
porous structure to form a collector, thereby manufacturing a
lithium metal electrode having lithium filled in the 3D porous
structure.
Example 2
[0046] An oxide-based high-ionic conductor
(La.sub.2/3Li.sub.1/3TiO.sub.3) was prepared in the same manner as
in Example 1 as a 3D porous structure (10.times.10.times.0.7 mm)
having open pores, in which the porosity was 65% and an average
pore size was about 2.5 .mu.m.
[0047] Then Al.sub.2O.sub.3 was coated on the interface in the form
of an ultrathin film by PVD (Physical Vapour Deposition) with
substrate temperature at 700.degree. C. Even though there was a
thickness gradient of a 3D porous structure, the thickness of the
Al.sub.2O.sub.3 coating was less than 10 nm from TEM investigation.
Because the solid high-ionic conductor (3D porous structure) reacts
with lithium, the reaction is prevented by adding the
Al.sub.2O.sub.3 coating step with nano-size thickness between
interfaces.
[0048] Then, each pore of the 3D porous structure manufactured as
described above was filled with lithium metal by placing the
structure in the argon-gas atmosphere and coating the pores with a
paste formed by mixing a few micrometers of lithium particles and a
binder.
[0049] As in Example 1, a copper collector was attached onto the
surface of the high-ionic conductor having the lithium-filled 3D
porous structure, thereby manufacturing a lithium electrode.
Example 3
[0050] An oxide-based high-ionic conductor
(La.sub.1.3Al.sub.0.3Ti.sub.1.7(PO.sub.4).sub.3) was provided as a
fine powder having an average particle size of 500 nm or less.
Then, a 3D porous structure (10.times.10.times.0.7 mm) having open
pores was prepared in the same manner as in Example 1, to provide a
porosity of 65% and a pore size of about 3.3 .mu.m.
[0051] Then Al.sub.2O.sub.3 was coated on the interface in the form
of an ultrathin film by PVD (Physical Vapour Deposition) with
substrate temperature at 700.degree. C. Even though there are
thickness gradient of a 3D porous structure. The thickness of the
Al.sub.2O.sub.3 coating was less than 10 nm from TEM investigation.
Because the solid high-ionic conductor (3D porous structure) reacts
with lithium, the reaction is prevented by adding the
Al.sub.2O.sub.3 coating step with nano-size thickness between
interfaces.
[0052] Lithium metal was then filled into each pore of the 3D
porous structure using the same melting method as in Example 1.
[0053] As in Example 1, a copper collector was attached onto the
surface of the high-ionic conductor having the lithium-filled 3D
porous structure, thereby manufacturing a lithium electrode.
Example 4
[0054] As in Example 3, an oxide-based high-ionic conductor
(La.sub.1.3Al.sub.0.3Ti.sub.1.7(PO.sub.4).sub.3) was provided as a
fine powder having an average particle size of 500 nm or less, and
the same method as in Example 1 was carried out to prepare a 3D
porous structure (10.times.10.times.0.7 mm) having open pores, in
which the porosity was 65% and an average pore size of about 6
.mu.m.
[0055] Then Al.sub.2O.sub.3 was coated on the interface in the form
of an ultrathin film by PVD (Physical Vapour Deposition) with
substrate temperature at 700.degree. C. Even though there are
thickness gradient of a 3D porous structure. The thickness of the
Al.sub.2O.sub.3 coating was less than 10 nm from TEM investigation.
Because the solid high-ionic conductor (3D porous structure) reacts
with lithium, the reaction is prevented by adding the
Al.sub.2O.sub.3 coating step with nano-size thickness between
interfaces.
[0056] In an argon-gas atmosphere, a paste formed by mixing lithium
particles of a few micrometers in size and a binder was coated onto
each pore of the 3D porous structure, thereby filling lithium metal
into the pore.
[0057] As in Example 1, a copper collector was attached onto the
surface of the high-ionic conductor having the lithium-filled 3D
porous structure, thereby manufacturing a lithium electrode.
Comparative Example
[0058] A liquid electrolyte (1M LiCF.sub.3SO.sub.3/0.5M LiTFSI+DME
[1,2-Dimethoxyethane, anhydrous, 99.5%]) was applied onto the
surface of a lithium metal foil (10.times.10.times.0.7 mm) used as
an anode of a conventional lithium metal battery, thereby
manufacturing a lithium electrode.
Test Example
[0059] Reaction surface areas with respect to the above lithium
electrodes according to Examples 1-4 and the lithium electrode
according to Comparative Example were compared. The results are
shown in Table 1 below.
TABLE-US-00001 TABLE 1 Porosity Pore Size Reaction of Solid of
Solid Surface Electrolyte Electrolyte Area of in in Lithium Item
Electrolyte Electrode Electrode Metal Example 1
La.sub.2/3Li.sub.1/3TiO.sub.3 70% 1.7 .mu.m 172941 mm.sup.2 Example
2 La.sub.2/3Li.sub.1/3TiO.sub.3 65% 2.5 .mu.m 109200 mm.sup.2
Example 3 La.sub.1.3Al.sub.0.3Ti.sub.1.7(PO.sub.4).sub.3 65% 3.3
.mu.m 82727 mm.sup.2 Example 4
La.sub.1.3Al.sub.0.3Ti.sub.1.7(PO.sub.4).sub.3 65% 6 .mu.m 45500
mm.sup.2 Compar- 1M LiCF.sub.3SO.sub.3/0.5M X X 100 mm.sup.2 ative
LiTFSI + DME[1,2- Example Dimethoxyethane, anhydrous, 99.5%]
[0060] As shown in the above Table 1, reaction surface areas of the
lithium electrodes according to Examples 1-4 are superior to that
in the Comparative Example. In particular, the lithium electrode
according to Example 1, which was manufactured to have a 3D porous
structure using the oxide-based high-ionic conductor
La.sub.2/3Li.sub.1/3TiO.sub.3, (i.e., a porosity of 70% and a pore
size of about 1.7 .mu.m) exceeding the lithium electrodes according
to Examples 2-4 in reaction surface area.
[0061] According to the present invention, a solid high-ionic
conductor having a 3D porous structure is manufactured, and lithium
is filled into each pore in various ways to manufacture a lithium
electrode. Unlike in a conventional lithium electrode in which
reactions occur on the lithium metal electrode surface of the
lithium metal battery (e.g., using a liquid electrolyte) which
degrades reactivity, the present invention secures a high-ionic
conduction path having a lithium-filled porous structure such that
the reaction may occur inside the pores in addition to the surface
of the lithium electrode. As such, the present invention improves
the charging and discharging cycle characteristics and output
characteristics of a lithium metal battery.
[0062] While exemplary embodiments of the present invention have
been described in detail, the protection scope of the present
invention is not limited to the foregoing embodiments and it will
be appreciated by those skilled in the art that various
modifications and improvements using the basic concept of the
present invention defined in the appended claims are also included
in the protection scope of the present invention.
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