U.S. patent application number 10/317222 was filed with the patent office on 2003-08-28 for solvents and novel electrolytic compositions having a large range of stability and high conductivity.
This patent application is currently assigned to ACEP Inc.. Invention is credited to Armand, Michel, Baril, Daniel, Bergeron, Jean-Yves, Brouillette, Dany, Michot, Christophe.
Application Number | 20030162096 10/317222 |
Document ID | / |
Family ID | 4161490 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030162096 |
Kind Code |
A1 |
Michot, Christophe ; et
al. |
August 28, 2003 |
Solvents and novel electrolytic compositions having a large range
of stability and high conductivity
Abstract
The present invention is concerned with novel polar solvents and
novel electrolytic compositions comprising such solvents, and
having a high range of stability, as required for applications in
the field of electrochemistry. The present solvents have a highly
polar amide function, and preferably combine with a salt soluble in
the solvent and having an anion with a delocalized charge, and at
least one polymer, to form an electrolytic composition.
Inventors: |
Michot, Christophe;
(Grenoble, FR) ; Brouillette, Dany; (Montreal,
CA) ; Baril, Daniel; (Montreal, CA) ;
Bergeron, Jean-Yves; (Longueuil, CA) ; Armand,
Michel; (Montreal, CA) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
ACEP Inc.
75 boulevard Rene-Levesque Ouest
Montreal
CA
H2Z 1A4
|
Family ID: |
4161490 |
Appl. No.: |
10/317222 |
Filed: |
December 12, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10317222 |
Dec 12, 2002 |
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09824103 |
Apr 3, 2001 |
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09824103 |
Apr 3, 2001 |
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09151599 |
Sep 11, 1998 |
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6296973 |
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Current U.S.
Class: |
429/307 ;
252/62.2; 429/213; 429/231.2; 429/231.3; 429/231.5; 429/231.8;
429/231.95; 429/303; 429/316; 429/317 |
Current CPC
Class: |
H01M 10/0564 20130101;
H01M 6/164 20130101; Y02E 60/13 20130101; C07C 311/48 20130101;
H01G 11/56 20130101; H01M 10/052 20130101; H01M 6/181 20130101;
H01G 9/038 20130101; H01M 10/0568 20130101; H01M 10/0565 20130101;
H01G 11/62 20130101; Y02E 60/10 20130101; H01M 10/0569 20130101;
H01M 2300/0085 20130101; C07C 381/10 20130101 |
Class at
Publication: |
429/307 ;
429/317; 429/316; 429/303; 429/231.95; 429/231.8; 429/231.5;
429/231.2; 429/231.3; 429/213; 252/62.2 |
International
Class: |
H01M 010/40; H01M
004/60; H01M 004/58 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 11, 1997 |
CA |
2,215,849 |
Claims
What is claimed is:
1. An aprotic polar compound having solvent properties, and of the
general formula: R.sup.1R.sup.2NX(Z)R.sup.7 wherein X.dbd.C or SO;
Z=O, NSO.sub.2NR.sub.3R.sub.4 or NCN; R.sup.1 et R.sup.2 are the
same or different and are C.sub.1-18alkyl, C.sub.1-18 oxaalkyl,
C.sub.1-18 alkylene or C.sub.1-18oxaalkylene; R.sup.3 R.sup.6 are
the same or different and are C.sub.1-18alkyl or C.sub.1-18
oxaalkyl; R.sup.7 is R.sub.F, R.sub.FCH.sub.2O--,
(R.sub.F).sub.2CHO--, (R.sub.FCH.sub.2).sub.2N-- or
NR.sup.5R.sup.6; R.sub.F is a fluorine atom, C.sub.1-4alkyl,
C.sub.1-4oxaalkyl C.sub.1-4azaalkyl, with the proviso that: 1) if
Z=O, then R.sub.F is not C.sub.1-4alkyl; and 2) if Z=O and
X.dbd.SO, then R.sup.5 or R.sup.6 is not is not C.sub.1-4alkyl or
C.sub.1-4oxaalkyl.
2. An aprotic polar compound according to claim 1 wherein the
C.sub.1-4alkyle, C.sub.1-4oxaalkyle or C.sub.1-4azaalkyle in the
definition of R.sub.F is essentially fluorinated.
3. An electrolytic composition comprising at least one polar
compound according to claim 1 or 2, a salt soluble in said compound
having an anion with a delocalized charge, and at least one
polymer.
4. An electrolytic composition according to claim 3, wherein the
salt comprises I.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-,
PF.sub.6.sup.-, AsF.sub.6.sup.-, SbF.sub.6.sup.-,
R.sub.FSO.sub.3.sup.-, XSO.sub.2NSO.sub.2X'.sup.-,
(XSO.sub.2)(X'SO.sub.2)(Y)C.sup.-, anionic derivatives of
4,5-dicyano-1,2,3-triazole, 3,5-bis(R.sub.F)-1,2,4-triazol- e,
tricyanomethane, pentacyanocyclopentadiene and
pentakis(trifluoromethyl- )cyclopentadiene,
R.sub.FSO.sub.2NCN.sup.-, C(CN).sub.3.sup.-,
R.sub.FSO.sub.2C(CN).sub.2.sup.-, and mixtures thereof, wherein X
and X' comprise R.sub.F, R.sub.FCH.sub.2O--, (R.sub.F) .sub.2CHO--,
(R.sub.FCH.sub.2) .sub.2N--, R.sup.8, R.sup.9R.sup.10N--, with the
proviso that at least one X or X' is R.sub.F, R.sub.FCH.sub.2O--,
(R.sub.F) .sub.2CHO--, or (R.sub.FCH.sub.2).sub.2N--;
Y.dbd.R.sub.F, R.sub.FSO.sub.2 or CN; R.sub.F is as defined above
and can be part of a macromolecular chain; and R.sup.8 to R.sup.10
are the same or different, and are C.sub.1-18alkyl or
C.sub.1-18oxaalkyl, and R.sup.8 --R.sup.10 can be part of a
macromolecular chain.
5. An electrolytic composition according to claim 4, wherein the
cation includes derivatives of alkaline metals, alkaline earth
metals, and organic cations of the "onium" type, comprising
ammonium, imidazolium, sulfonium, phosphonium, oxomum or mixtures
thereof.
6. An electrolytic composition according to claim 5, wherein the
cation is at least party lithium.
7. An electrolytic composition according to claim 3 further
comprising a co-solvent.
8. An electrolytic composition according to claim 7, wherein the
co-solvent is aprotic and polar, and comprises dialkyl ethers of
ethylene glycol, diethylene glycol, triethylene glycol,
polyethylene glycols; carbonic acid esters, .gamma.-butyrolactone,
nitriles, tricyanohexane, dimethyl formnamide,
N-methylpyrrolidinone, or mixtures thereof.
9. An electrolytic composition according to claim 8, wherein the
polyethylene glycol mass is comprised between 400 and 2000.
10. An electrolytic composition according to claim 3, wherein the
polymer comprises monomer units derived from ethylene oxide,
propylene oxide, epichlorohydrine, epifluorohydrine,
trifluoroepoxypropane, acrylonitrile, methylmetacrylate, vinylidene
fluoride, and N-vinylpyrolidinone, hexafluoropropene, either as
homo- or copolymers, or mixtures thereof.
11. An electrolytic composition according to claim 8, wherein the
composition is plasticized or in the form of a gel.
12. An electrolytic composition according to claim 9, wherein at
least one polymer is a polyclectrolyte comprising a macromolecular
woof similar to that of anions having a delocalized charge.
13. An electrochemical generator comprising as an electrolyte an
electrolytic composition according to claim 3.
14. An electrochemical generator according to claim 13, wherein the
negative electrode contains lithium metal, a lithium alloy, an
carbon intercalation compound, an oxide having a low potential of
intercalation, a double nitride of a transition metal in lithium,
or mixtures thereof.
15. An electrochemical generator according to claim 14, wherein the
carbon intercalation compound is petroleum coke or graphite, and
wherein the oxide having a low potential of intercalation is a
titanium spinel.
16. An electrochemical generator according to claim 14, wherein the
positive electrode contains vanadium oxide, a mixed oxide of
lithium and vanadium, an oxide of cobalt and lithium, a manganese
spinel, a double phosphate of the olivine or Nasicon structure, a
salt of rhodizonic acid, a polysidulfide derived from the oxidation
of 2,5-dimercapto-1,3,4-thiadi- azole,
2,5-dimercapto-1,3,4-oxadiazole,
1,2-dimercaptocyclobutene-3,4-dion- e, or mixtures thereof.
17. An energy storage system of the supercapacitor type comprising
as an electrolyte an electrolytic composition according to claim 3.
Description
FIELD OF INVENTION
[0001] The invention concerns new polar solvents and new
electrolytic compositions comprising the same, and having a large
range of stability, as required for applications in the field of
electrochemistry.
BACKGROUND OF THE INVENTION
[0002] Polar aprotic solvents such as cyclic or linear carbonates,
or ethers used alone or in mixtures, are known in various
electrolytic compositions. The stability of these products towards
highly negative potentials, close to those of alkaline metals, or
highly positive (.gtoreq.4V with respect to Li.sup.+/Li.sup.o), are
not satisfactory, and lithium batteries containing electrolytes
obtained from the dissolution of a lithium salt in these solvents
create serious safety problems. Products of the amide type, whether
linear or cyclic, such as dimethylformamide or
N-methylpyrrolidinone, possess excellent properties as solvents,
but are oxidized at potentials that are still lower, in the order
of 3.7V with respect to Li.sup.+/Li.sup.o.
[0003] Numerous materials of positive electrodes, such as mixed
oxides of transition metals and lithium work under potentials near
4 V with respect to Li.sup.+/Li.sup.o and therefore require
electrolyte stabilities significantly higher than that value. For
example, products like
Li.sub.1-yCo.sub.1-x-zNi.sub.xAl.sub.yO.sub.2 wherein x+y.ltoreq.1
and z.ltoreq.0,3); manganese spinels
Li.sub.1-.alpha.Mn.sub.2-xM.sub.xO.sub.4-
.Li.sub.1-.alpha.Co.sub.1-x-yNi.sub.xAl.sub.y wherein
0.ltoreq.x+y.ltoreq.1; 0.ltoreq.y.ltoreq.0,3;
0.ltoreq..alpha..ltoreq.1 and M=Li, Mg, Al, Cr, Ni, Co, Cu, Ni,
Fe.
[0004] U.S. Pat. Nos. 4,851,307 and 5,063,124 describe electrolytes
comprising a salt, a solvating polymer and an aprotic sulfamide of
the general formula
R.sup.1R.sup.2NSO.sub.2R.sup.3R.sup.4
[0005] wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, the same or
different, are independently selected from C.sub.1-10alkyl or
C.sub.1-10oxaalkyl. An example of the product of that group is the
tetraethylfulfamide
(R.sup.1.dbd.R.sup.2.dbd.R.sup.3.dbd.R.sup.4.dbd.C.su- b.2H.sub.5).
These materials have increased stability towards reducing or basic
agents present and having potentials near those of alkaline metals.
However, they are oxidized at potentials between 3.8 and 4V with
respect to Li.sup.+/Li.sup.o.
[0006] EP 0 339 284 discloses dielectric and insulating compounds
like perfluoro-acylamides or perfluoro-sulfonamides
R.sub.FCONA.sup.1A.sup.2 and R.sub.FSO.sub.2NA.sup.1A.sup.2,
wherein A.sup.1 and A.sup.2 are alkyl groups. The proposed use of
these products in capacitors implies that the materials are not
conductive and that the impurities and inevitable contaminants,
particularly ionic products, are not inducing significant
conductivity.
[0007] The publication of Sartori et al. in an abstract of a
meeting of the Electrochemical Society, Volume 97-1, May 1997,
describes certain sulfonamides that could be used as electrolytes
in a battery or in an energy storage system.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, there is provided
novel polar solvents and novel electrolytic compositions comprising
the same and having a high degree of stability, as required for
applications in the field of electrochemistry. More specifically,
the solvents of the present invention are of the general
formnula
R.sup.1R.sup.2NX(Z)R.sup.7
[0009] wherein
[0010] X.dbd.C or SO;
[0011] Z=O, NSO.sub.2NR.sub.3R.sub.4 or NCN;
[0012] R.sup.1 et R.sup.2 are the same or different and are
C.sub.1-18alkyl, C.sub.1-18oxaalkyl, C.sub.1-18 alkylene or
C.sub.1-18oxaalkylene;
[0013] R.sup.3 R.sup.6 are the same or different and are
C.sub.1-18alkyl or C.sub.1-18 oxaalkyl;
[0014] R.sup.7 is R.sub.F, R.sub.FCH.sub.2O--,
(R.sub.F).sub.2CHO--, (R.sub.FCH.sub.2).sub.2N-- or
NR.sup.5R.sup.6;
[0015] R.sub.F is fluorine, C.sub.1-4alkyl, C.sub.1-4oxaalkyl or
C.sub.1-4azaalkyl wherein the alkyl chain is preferably essentially
fluorinated and partly chlorinated,
[0016] with the provisos that:
[0017] 1) if Z=O, then R.sub.F is not C.sub.1-4alkyl; and
[0018] 2) if Z=O and X=SO, then R5 or R6 is not C.sub.1-4alkyl or
C.sub.1-4oxaalkyl.
[0019] The expression "essentially fluorinated" means that the
degree of fluorination in the chain is sufficient to provide
properties similar to those obtained with a chain entirely
perfluorated, such as a hydrophobic character and properties of
attracting electrons. Preferably, at least half of the hydrogen
atoms of the chain are replaced by fluorine atoms. The expression
"partially chlorinated" means that within the essentially
fluorinated products, the hydrogen atoms remaining are at least
partially replaced with chlorine atoms.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the present invention, materials with a highly polar
amide function are used for preparing electrolytic compositions
useful for electrochemical applications. It has unexpectedly been
found that groups strongly attracting electrons, when combined with
the amide function, allow the maintenance of solubilizing power
towards ionic products, particularly those having a highly
delocalized anionic charge, and thus inducing high ionic
conductivities. By adding a polar polymer to these compositions,
there is obtained electrolytes with mechanical properties allowing
the fabrication of films for use in electrochemical devices, and
increasing the security when in operation. Depending on the amount
of polar solvent and polymer in the electrolytic compositions, the
consistency thereof can be adjusted to a gel or a plasticized
polymer. Further, the polymers can be reticulated to improve
mechanical properties.
[0021] The electrolytic compositions of the present invention have
higher stability when compared to materials of the prior art,
particularly at very anodic potentials, especially those exceeding
4 V with respect to Li.sup.+/Li.sup.o.
[0022] Preferred low energy reticular salts that are soluble in the
polar solvents of the present invention to form conductive
solutions comprise those having a delocalized charge, such as
I.sup.-, ClO.sub.4.sup.-, BF.sub.4.sup.-, PF.sub.6.sup.-,
AsF.sub.6.sup.-, SbF.sub.6.sup.-, R.sub.FSO.sub.3.sup.-,
XSO.sub.2NSO.sub.2X'.sup.-, (XSO.sub.2)(X'SO.sub.2)(Y)C.sup.- and
mixtures thereof, wherein
[0023] X and X' is R.sub.F, R.sub.FCH.sub.2O--,
(R.sub.F).sub.2CHO--, (R.sub.FCH.sub.2).sub.2N--, R.sup.8,
R.sup.9R.sup.10N--, with the proviso that at least one X or X' is
R.sub.F, R.sub.FCH.sub.2O--, (R.sub.F).sub.2CHO--,
(R.sub.FCH.sub.2).sub.2N--;
[0024] Y.dbd.R.sub.F, R.sub.FSO.sub.2 or CN;
[0025] R.sub.F is as defined above; and
[0026] R.sup.8 to R.sup.10 are the same or different, and are
C.sub.1-18alkyl or --C.sub.1-18 oxaalkyl.
[0027] R.sub.F and R.sup.8-R.sup.10 can be part of a molecular
chain. Also preferred are anions derived from
4,5-dicyano-1,2,3-triazole, 3,5-bis(R.sub.F)-1,2,4-triazole,
tricyanomethane, pentacyanocyclopentadie- ne and
pentakis(trifluoromethyl)-cyclopentadiene and anions derived from
cyanamide and malononitrile, i.e., R.sub.FSO.sub.2NCN.sup.-,
C(CN).sub.3.sup.-, R.sub.FSO.sub.2C(CN).sub.2.sup.-. Preferred
cations comprise those derived from alkaline metals, more
preferably lithium, alkaline earth metals, and organic cations of
the "onium" type, such as ammonium, imidazolium, sulphonium,
phosphonium and oxonium.
[0028] With respect to the electrolytic compositions of the present
invention, they include those containing at least one polar solvent
as defined above in combination with one or more polar molecules
acting as a co-solvent. Such other polar molecules include solvents
capable of forming compatible mixtures, such as dialkyl ethers of
ethylene glycol, diethylene glycol, triethylene glycol,
polyethylene glycols preferably having a mass of from 400 to 2000;
or esters, preferably carbonic acid esters, whether linear or
cyclic, such as dimethylcarbonate, methylethylcarbonate,
diethylcarbonate, ethylene carbonate, propylene carbonate, or
esters such as .gamma.-butyrolactone, nitrites such as
glutaronitrile, or 1,2,6-tricyanohexane. These other polar
molecules, or co-solvent, can be added alone or in mixtures to the
solvent of the present invention. An example of the preferred
mixture is ethylene carbonate with a dialkyl ether.
[0029] The present invention further includes solid electrolytes
obtained by the addiiton of the polymer to a solvent or
solvent-co-solvent mixture containing at least one salt as defined
above in solution. The amount of polymer can be selected so that
the solvent acts as a plasticizing agent of the polymer, i.e. in
concentration of 3 to 30% by weight, preferably between 10 and 25%
by weight. Preferred polymers for such compositions are those with
monomer units containing solvating units, such as those derived
from ethylene oxide, propylene oxide, epichlorohydrine,
epifluorohydrine, trifluoroepoxypropane, etc. To obtain a gel, the
amount of solvent and salt in the composition should be between 30
and 95% by weight, preferably between 40 and 70%. In addition to
the polymers listed above, those containing units derived from
acrylonitrile, methylmethacrylate, vinylidene fluoride,
N-vinylpyrolidinone are also preferred, and can be either homo- or
copolymers, such as vinylidene fluoride and hexafluoropropene
copolymers. A copolymer containing from 5 to 30% molar of
hexafluoropropene is particularly preferred. In a variation, the
polymers are polyelectrolytes incorporating anions with a
delocalized charge in the macromolecular woof. In such conditions,
negative charges are immobilized and only positive counter-charges
participate in the ionic conduction process.
[0030] The present electrolytic compositions can be used wherever a
high stability is required, particularly when oxidation or highly
positive potentials are present. A good example is an
electrochemical generator wherein it is advantageous to have a high
electromotive force, particularly in generators containing lithium
ions. In such systems, the negative electrode comprises metallic
lithium, one of its alloys, a carbon derivative, preferably
petrolium coke or graphite, an oxide with a low potential of
intercalation such as titanium spinels
Li.sub.2x+1+3yTi.sub.x+5O.sub.12 (x.gtoreq.0 and y.ltoreq.1), a
double nitride of a transition metal and lithium such as
Li.sub.3-xCo.sub.xN, or having an antifluorite type structure such
as Li.sub.3FeN.sub.2 or Li.sub.7MnN.sub.4.
[0031] The materials for the positive electrode comprise
intercalation compounds, polydisulfides or oxocarbones.
Intercalation compounds include vanadium oxide, and preferably
those with the formula VO.sub.x wherein 2.ltoreq.x.ltoreq.2.5;
LiV.sub.3O.sub.8; cobalt and lithium mixed oxides of the general
formula Li.sub.1-.alpha.Co.sub.1-x-yNi.sub.xAl.sub.y wherein
0.ltoreq.x+y.ltoreq.1; 0.ltoreq.y.ltoreq.0,3;
0.ltoreq..alpha..ltoreq.1; partly substituted manganese spinels of
the general formula Li.sub.1-.alpha.Mn.sub.2-zM.sub.zO.sub.4
wherein 0.ltoreq.z.ltoreq.1 and M=Li, Mg, Al, Cr, Ni, Co, Cu, Ni,
Fe; and double phosphates of the olivine or Nasicon structure such
as Li.sub.1-.alpha.Fe.sub.1-xMn.sub.xPO.sub.4,
Li.sub.1-.alpha.+2xFe.sub.2P.- sub.1-xS.sub.xO.sub.4' wherein
x.gtoreq.0 and .alpha..ltoreq.1. Oxocarbones electrode materials
are preferably rhodizonic acid salts; polydisulfides including
derivatives resulting from the oxidation of dimercaptoethane,
2,5-dimercapto-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-oxaadiazole,
and 1,2-dimercaptocyclobutene-3,4-dione- .
[0032] Electrochemical generators using the present electrolytic
compositions preferably contain solid electrolytes, either
plasticized or gelled. In a preferred embodiment of the invention,
at least one of the electrodes is a composite comprising the
electrode materials in a mixture with the electrolytic composition
and carbon such as Shawinigan.RTM. black, Ketjenblack.RTM., or
graphite.
[0033] Another application of the invention is that of
supercapacitors wherein at least one electrode comprises high
surface area carbon, and the electrical energy is stored as a
result of the capacity of the double layer between the carbonated
material and the electrolyte. In a preferred embodiment, the two
electrodes are symmetrically built with carbon having high surface
area, and this material is mixed with the electrolyte to form a
composite. Another possibility is to use the electrode material
containing at least one polymer having conjugated double bonds. In
a preferred embodiment, the conjugated polymer may have three
degrees of oxidation, obtained by reduction ("n" doping)
concomitant to an injection of electrons and cations, or by
oxidation ("p" doping) concomitant to an electron extraction and
anion injections, from the neutral form. Polymers comprising
phenyl-3-thiophene, and particularly poly(4-fluorophenyl-3-thi-
ophene) are preferred.
[0034] The following examples are provided to illustrate the
preferred embodiments of the present invention, and should not be
construed as limiting its scope.
EXAMPLE 1
[0035] Trifluoroethanol (18.2 mL, 25 mml) dissolved in 100 mL of
ether are added to 7 g of sodium hydride. When no more hydrogen gas
evolves, the solution is centrifuged and the supernatant clear
liquid is added at 0.degree. C. to 35 .mu.g (25 mml) of
dimethysulfamoyl chloride dissolved in 100 mL of dry ether under
stirring. A white precipitate of NaCl forms and the reaction is
completed in two hours. The slurry is filtered and the ether
stripped in a rotary evaporator. The residue is diluted with 50 ml
of dichloromethane and washed with 10% HCl in water. The organic
layer is separated, dried with anhydrous magnesium sulfate. The
corresponding trifluoethyl-N,N dimethylsulfamate is distilled under
reduced pressure. RMN: .sup.19F: triplet .delta.=74.7 ppm,
J.sub.HF=8.1 Hz; .sup.1H: quartet .delta.=4.66 (2H), singlet
.delta.=3.6 (6H). The conductivity of the lithium salts of the
bis(trifluoromthanesulfonimide) (CF.sub.3SO.sub.2).sub.2NLi in
solution in this solvent is provided in Table 1 with respect to
several concentrations.
1 TABLE 1 molality (mol.kg.sup.-1) conductivity .kappa..sub.sp
(S.cm.sup.-1) 0.265 0.634 0.506 0.922 0.898 1.025 1.160 0.796
[0036] The range of electrochemical stability is measured by cyclic
voltametry on a platinum microelectrode (15 .mu.m diameter) for
anodic potentials, and nickel for cathodic potentials. The
stability range is from 0 to 5.2 V vs. Li+/Li.sup.o. The variation
of conductivity with respect to the temperature is found is Table 2
for a concentration of 0.898 mol.kg.sup.-1.
2 TABLE 2 T (.degree. C.) .kappa..sub.sp (S.cm.sup.-1) T (.degree.
C.) .kappa..sub.sp (S.cm.sup.-1) 14.90 0.753 30.29 1.203 14.92
0.7550 35.39 1.415 19.93 0.882 40.81 1.657 25.11 1.030
EXAMPLE 2
[0037] 107.4 mL of dimethylsulfamoyl chloride are heated under
reflux and nitrogen atmosphere with 70 g of potassium fluoride and
10 mL of water. The mixture is cooled and extracted with
dichloromethane, dried with magnesium sulphate, and distilled. The
compound obtained, (CH.sub.3).sub.2NSO.sub.2F, has a dielectric
constant greater than 30. The range of stability, as determined by
cyclic voltametry, is 5 V vs. Li+/Li.sup.o. The lithium salt of the
fluorosulfonimide (FSO.sub.2).sub.2NLi is soluble in this medium,
and its conductivity at 25.degree. C. is greater than 1 mScm.sup.-1
for concentrations between 0.5 and 1 mole.kg.sup.-1.
EXEMPLE 3
[0038] 1.6 g of sodium hydride are added to 6.3 mL of
1,1,1,-3,3,3,-hexafluoropropanol dissolved in 25 ml of anhydrous
ether. When no more hydrogen gas evolves, the solution is
centrifuged, and 8,6 .mu.g (60 mml) of dimethylsulfamoyl chloride
dissolved in 25 mL of dry ether are added to the supernatant liquid
under agitation at a temperature of 0.degree. C. A white
precipitate of sodium chloride is then formed et the reaction is
completed after 2 hours. The slurry is filtered and the ether is
evaporated with a rotary evaporator. The residue is placed in 20 mL
of dichloromethane and washed with an aqueous solution of 10%
hydrochloric acid. The organic phase is separated and dried with
anhydrous magnesium sulphate. The hexafluoropropyle
N,N-dimthylsulfamate is obtained by evaporating the dichloromethane
and distilled under reduced pressure. The compound has a dielectric
constant greater than 20, and the conductivity of solutions of
salts of bis(trifluoromethanesulfonimide)
(NC.sub.2H.sub.5).sub.4(CF.sub.3SO.sub.2- ).sub.2N in this solvent
are between 5.times.10.sup.-4 and 2.times.10.sup.-3 Scm.sup.-1 at
25.degree. C. in concentrations varying from 0.2 to 1
mole.kg.sup.-1.
EXAMPLE 4
[0039] 4.2 g of cyanamide and 11.22 g of diazabicyclo 2,2,2-octane
(DABCO) are added to 15.76 g of ethylmethylsulfamoyl chloride
dissolved in 100 mL of tetrahydrofuran. After agitating the mixture
at room temperature for 8 hours, 13 g of oxalyl chloride dissolved
in 40 mL of anhydrous tetrahydrofuran are added dropwise. After gas
ernissions have stopped (CO and CO.sub.2), the DABCO chlorohydrate
is filtered and remaining THF is evaporated under reduced pressure.
The solid is then placed in 50 mL of acetonitrile to which is added
12.2 g of ethylmethylamine at 0.degree. C. The ethylmethylammonium
chloride thus obtained is separated and the solvent is evaporated
under reduced pressure. The polar product 1
[0040] The polar product is solubilized in dichloromethane, and
washed with water containing 2% hydrochloric acid, and subsequently
5% sodium bicarbonate. Following removal of dichloromethane, the
compound is distilled under reduced pressure. This product can be
used as a solvent for delocalized anions salts, particularly
perfluorinated imides.
EXAMPLE 5
[0041] 33 g of 1,1-dimethylsulfamide
(CH.sub.3).sub.2SO.sub.2NH.sub.2 and 6 g of caustic soda in 200 mL
of water are heated to reflux for 2 hours. The reaction product,
the sodium salt of bis(dimethylaminosulfonimide), i.e.,
Na[N(SO.sub.2N(CH.sub.3).sub.2)], is obtained by evaporation of the
water and recristallisation in ethanol. 25 g of this salt suspended
in 100 mL of anhydrous are reacted with 9 mL of oxalyl chloride. At
then end of the reaction, i.e., no more gas emissions, the slurry
is cooled to 0.degree. C. and 20.7 mL of diethylanine dissolved in
50 mL of acetonitrile are added. The mixture is then agitated for 4
hours at room temperature, and subsequently filtered. Any remaining
acetonitrile is removed under reduced pressure. The liquid obtained
is solubilized in dichloromethane and washed with water containing
2% hydrochloric acid, and subsequently 5% of sodium bicarbonate.
The solution is passed through an alumina column and the
dichloromethane is evaporated under reduced pressure. The polar
solvent 2
[0042] is kept anhydrous by adding lithium hydride.
EXAMPLE 6
[0043] An electrochemical generator comprising a negative electrode
of lithium of 25 .mu.m on a nickel support of 10 .mu.m, a positive
electrode composite containing 78% by weight of vanadium oxide
V.sub.2O.sub.5, 8% of carbon black (Ketjenblack.RTM.) and 14% of a
vinylidene fluoride--hexafluoropropene copolymer on a nickel
collector (10 .mu.m) has been prepared. The positive electrode
capacity thus obtained by spreading from a cyclohexanone
suspension, is 2.8 mAh/cm.sup.2. The electrolyte comprises a
solution of 0.15 M.kg.sup.-1 of Li(CF.sub.3SO.sub.2).sub.2N in the
polar compound of Example 1 in a polypropylene porous separator of
the Celgard.RTM. type. The generator was cycled over 150 cycles
between 1.6 et 3.4V at C/3.7 while maintaining a ratio of charge
and discharges capacities equal to 1 and a use rate of>75% over
30 cycles. The ohmic drop remained between 20 and 120 mV.
EXEMPLE 7
[0044] An electrochemical generator of the "rocking chair" type was
prepared with 2 composite electrodes similar to those of Example 6.
Lithium and titanium spinel Li.sub.4Ti.sub.5O.sub.12 was used as
the negative electrode, to give a surface capacity of 2.6
mAh.cm.sup.-2. Lithium cobaltite was used for the positive
electrode, to give a surface capacity of 2.4 mAh.cm.sup.-2. The
electrolyte was prepared in a manner similar to that of Example 6
with a solution of 0.15 M.kg.sup.-1 of Li(CF.sub.3SO.sub.2).sub.2N
in the polar compound of Example 1 in a polypropylene porous
separator of the Celgard.RTM. type. The generator was cycled over
500 cycles between 1.5 et 3.3 V C/4 while maintaining a ratio of
charge and discharges capacities equal to 1 and a use rate of
80%.
EXEMPLE 8
[0045] An electrochemical generator of the supercapacitor type is
prepared with 2 symetrical composite electrodes of high surface
area carbon (680 m.sup.2.g.sup.-1) and nickel fibres on a nickel
support, and bound by a vinylidene fluoride--hexafluoropropene
copolymer. The electrolyte comprises 75% by wieght of a gel of a
molar solution of tetraethylammonium fluorosulfonimide
(C.sub.2H.sub.5).sub.4N[(CF.sub.3SO.- sub.2).sub.2N] in the same
polymer. The system capacity is 1.2 F.g.sup.-1 over 12 000 cycles
performed between 0 and 2.5 V.
EXEMPLE 9
[0046] A polymer electrolyte is prepared by plasticizing an
ethylene oxide--allylglycidyl ether copolymer containing the
lithium salt of dimethylaminosulfonyl-trifluoromethane-sulfonimide
Li[(CH.sub.3).sub.2SO.sub.2NSO.sub.2CF.sub.3] with a ratio oxygen
from the ether functions of the polymer to lithium of 14:1 with the
polar compound of Example 5 with a weight ratio 65:35. This
electrolyte has a conductivity of 10.sup.-4 Scm.sup.-1 at
25.degree. C. and an electrochemical stability range of 0 to 4V vs.
Li.sup.+/Li.sup.o. This electrolyte can be reticulated by a free
radical source to give elastomers with good mechanical
properties.
[0047] While the invention has been described in connection with
specific embodiments thereof, it will be understood that it is
capable of further modifications and this application is intended
to cover any variations, uses or adaptations of the invention
following, in general, the principles of the invention and
including such departures from the present description as come
within known or customary practice within the art to which the
invention pertains, and as may be applied to the essential features
hereinbefore set forth, and as follows in the scope of the appended
claims.
* * * * *