CA2246955C - Solvents and novel electrolytic compositions having a high stability domain and high conductivity - Google Patents

Abstract

The present invention relates to novel polar solvents and novel electrolytic compositions derived therefrom and possessing a high stability domain, as required for applications in the electrochemical field. These solvents have a very polar amide function, and are preferably combined with a salt soluble in said solvent and having a delocalised charge anion, and at least one polymer, to form an electrolytic composition.

Description

TITLE

Solvents and new electrolytic compositions having a broad area of stability and high conductivity FIELD OF THE INVENTION

The field of the invention is that of new polar solvents and new electrolytic compositions derived therefrom and having a field of stability high, as required for applications in the electrochemical field.

PRIOR ART

Polar aprotic solvents such as carbonates are known cyclic or linear, the ethers used alone or as a mixture, in many electrolytic compositions. The stability of these compounds against very potential negative, close to those of alkaline metals, or very positive (> 4V per report to Li + / Li), is far from satisfactory, and lithium batteries including electrolytes obtained by dissolving a lithium salt in these solvents pose of serious security problems. Linear amide compounds or cyclic Dimethylformamide or N-methylpyrrolidinone have excellent properties as solvents but oxidize at still low potentials, the order of 3.7 V with respect to Li + / Li.

Many positive electrode materials, such as oxides mixed transition metals and lithium work at potentials close to 4 V with respect to Li + / Li and therefore require electrolyte stabilities clearly greater than this value. For example, the compounds Li, _, Co, _X_ZNiXAlyOz wherein

-2-x + y <1 and z S 0.3); manganese spinels Li, _aMn2_XMXO4 =
Li, _aCo, _X_YNiXAIY in lesquels0 <_x + y <1; 0 <_y <_0,3; 0 <_a <_1etM = Li, Mg, A1, Cr, Ni, Co, Cu, Ni, Fe.
US Patents 4,851,307 and 5,063,124 describe a family of electrolytes employing a salt, a solvating polymer and a solvent aprotic of the sulphonamide family of general formula R'R2 NSO2R3R4 where R ', R2, R3 and R4, which are identical or different, are chosen independently from C, _, oalkyl or C, _, ooxaalkyl groups. A representative example of this group is the tetraethylsulfamide (R '= R2 = R3 = R4 = CzHs). These materials have a increased stability against reducing or basic agents present with potentials close of those alkali metals. On the other hand, they are oxidizable with potentials understood between 3.8 and 4V with respect to Li + / Li.

The compounds described in European Patent EP 0 339 284 consist of dielectric and insulating compounds consisting of perfluoroacylamides or perfluoro-sulfonamides RFCONA'Az and RFSO2NA'A2, where A 'and Az are groups alkyls. The proposed use of these compounds in capacitors implies that these materials have no conductivity and that impurities and contaminations inevitable, in particular by ionic compounds, does not induce an increase in conductivity appreciable.

The publication of Sartori et al. in an abstract of a meeting of Electrochemical Society, Volume 97-1, May 1997, describes, among other things, that some

-3-sulphonamides could be used as an electrolyte in a battery or in one energy storage system.

SUMMARY OF THE INVENTION

The present invention relates to a series of new polar solvents and new electrolytic compositions derived from it and possessing a domain of high stability, as required for applications in the field electrochemical. More specifically, the solvents of the present invention correspond to the general formula R'RzNX (Z) R ' in which X = Couso;
Z = O, NSO2NR3R4 or NCN;

R 'and R2 are the same or different and represent C1_18alkyl, C, _, g oxaalkyl, C1_18 alkylene or C1-18alkaalkylene;

R3 to R6 are the same or different and represent C1_18alkyl or C, _, g oxaalkyl;

R 'is an RF group, a group RFCH2O-, (RF) 2CHO-, (RFCH2) 2N- or NRSR6;
RF is a fluorine atom, a C1-4alkyl, C1-4alkylalkyl group or C1_4azaalkyl in which the alkyl group is preferably substantially fluorinated and partially chlorine, with the restrictions that:

1) if Z = O, then RF is not C1-4alkyl; and 2) if Z = O and X = SO, then RS or R6 is not C1-4alkyl or C1-4alkalkyl.

The expression "essentially fluorinated" means that the degree of fluoridation of the chain is sufficient to confer properties similar to those of chains perfluorinated substances, such as hydrophobicity and attractor

-4-electron. Preferably, at least about half of the hydrogen atoms of the chain are replaced by fluorine atoms. The expression "partially chlorinated "
means that the partially fluorinated compounds, the hydrogen atoms remaining are at least partially replaced by chlorine atoms.

DETAILED DESCRIPTION OF THE INVENTION

In the present invention, materials having an amide function very polar are used as a basis for the preparation of compositions electrolytes useful for electrochemical applications. It has been found that of quite unexpected way, groups very strongly attractors electron associated with the amide function allow to maintain a solubilizing power facing ionic compounds, especially those whose anionic charge is strongly delocalized, and thus induce high ionic conductivities. In adding a polar polymer to these compositions, electrolytes having properties i5 mechanical facilitating their implementation, particularly in the form of movies, for their use in electrochemical devices and increasing their safety of operation. Depending on the respective amounts of polar solvent and polymer in the electrolytic compositions, the consistency of these is similar to that of a gel or that of a plasticized polymer. In addition, the polymers can be crosslinked to improve the mechanical properties.

Compared to the materials of the prior art, the new compositions electrolytics of the present invention have increased stability, particular at very anodic potentials, especially those exceeding 4V compared to Li +
/ Li.

-5-Preferential low-energy reticular salts that are soluble in the polar solvents of the present invention to form solutions conductive include those with a delocalized load, such as I-, C104-, BF4-, PF6-, AsFb, SbF6-1 RFSO3-, XSOZNSO2X'-, (XSOZ) (X'SOZ) (Y) C- and mixtures thereof, wherein X and X 'are selected from RF, RFCH 2 O-, (RF) 2 CHO-, (RFCH 2) 2 N-, R 8, R 9 R 10 N-, with the restriction that at least one X or X 'is selected from RF, RFCH2O-, (RF) 2CHO-, (RFCH2) 2 N-;

- Y = RF, RFSOz or CN;

RF is as previously defined; and R8 to R10 are the same or different, and represent C, galkyl or C, _, 8oxaalkyle; RF
and R8-R10 may be part of a macromolecular chain. Are also favorite ones anions derived from 4,5-dicyano-1,2,3-triazole, 3,5-bis (RF) -1,2,4-triazole, the tricyano-methane, pentacyanocyclopentadiene and pentakis (trifluoromethyl) cyclopentadiene and anions derived from cyanamide and malononitrile, ie, RFSOZNCN-, C (CN) 3-1 RFSO2C (CN) 2. Preferential cations are chosen from those derived from metals alkali, in particular lithium, alkaline earth metals, cations organic "onium" type, in particular ammonium, imidazolium, sulphonium, phosphonium and oxonium.

Among the electrolytic compositions which are the subject of this invention, those containing at least one polar solvent such as defined previously in combination with one or more other polar molecules in so than co-solvent. Other polar molecules include solvents likely to form compatible mixtures, for example the di-alkyl ethers of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycols having

-6-preferably a mass of between 400 and 2000; or the esters, in especially those carbonic acid, linear or cyclic, such as dimethylcarbonate, methyl-ethylcarbonate, diethylcarbonate, ethylene carbonate, carbonate of propylene;
or esters such as γ-butyrolactone, nitriles such as glutaronitrile, or 1,2,6-tricyanohexane. These other polar molecules, or co-solvent, can be added only to the solvent of the present invention, or in admixture. An example of mixed preferential is the mixture of ethylene carbonate with a diethyl ether.
alkyl.

The present invention further includes solid electrolytes obtained by addition of a polymer to solvents or mixture of solvents - co-solvents containing at minus a salt in solution as defined above. The proportion of polymer may be chosen so that the solvent acts as plasticizer of the polymer, in fraction of 3 to 30% by weight, preferably 10 to 25% by weight. The polymers Preferred for these compositions are those whose monomeric units possess of the solvating units, such as those derived from ethylene oxide, propylene, epichlorohydrin, epifluorohydrin, tri fluoroepoxypropane etc. The polymer can also serve to constitute a gel when the mass fraction of the solvent and the salt is between 30 and 95% by weight, preferably 40 to 70%. In addition to polymers above, those containing units derived from acrylonitrile, methacrylate methyl, vinylidene fluoride and N-vinylpyrolidinone are also and may be homo- or co-polymers. In particular, can mention copolymers of vinylidene fluoride and hexafluoropropene. A
copolymer containing from 5 to 30 mol% of hexafluoropropene is particularly advantageous. In one variant, the polymers are polyelectrolytes incorporating in the macromolecular weft of the type anions of those dependent delocalized. In

-7-these conditions, the negative charges are immobilized and only the counter-loads positive ones participate in the process of ionic conduction.

The electrolytic compositions of the invention are usable in all cases where a high degree of stability is required, more particularly vis-à-vis oxidation or very positive potentials. A good example is a generator electrochemical in which is advantageous to have a high electromotive force, and more particularly generators involving the lithium ion. In such a system, the negative electrode consists of lithium metal, one of its alloys, a carbon insertion compound, in particular petroleum coke or graphite, a oxide with low insertion potential such as titanium spinels Lizx +, + 3yTix + 5O12 (x> _ 0 and y <1), a double nitride of a transition metal and lithium as Li3_XCoN, or having the antifluorite type structure such as Li3FeNz or Li7MnN4.

The positive electrode materials are chosen from the compounds insertion, polydisulphides or oxocarbones. Among the compounds insertion, are preferred vanadium oxide, and preferably that of formula VO, or 2 <_ x <_ 2.5; LiV3O8 mixed lithium and vanadium oxide; oxides double of partially substituted cobalt and lithium of the general formula Li, _aCo, _, _ YNiAIy in where 0 <_ x + y <1; 0 <y <0.3; 0 5 a <_ 1; manganese spinels partially substituted compounds of the general formula Li, _aMn2_ZMZO4 in which 0 <_ z <1 and M = Li, Mg, Al, Cr, Ni, Co, Cu, Ni, Fe; and double phosphates of olivine structure or Nasicon such that Li1_aFe1_XMnPO41 Li, _ ~. + 2XFe2P, _xSxO4, in which x> _ 0 and a <_ 1. The materials oxocarbon type electrodes are preferably chosen from acid rhodizonic, the polydisulphide are chosen from those derived from oxidation of

-8-dimercaptoethane, 2,5-dimercapto-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-oxaadiazole, 1,2-dimercaptocyclobutene-3,4-dione.

Electrochemical generators using the compositions electrolytes according to the invention preferably use electrolytes solid, type plasticized or gel form. In a preferred embodiment of the invention, at least one of the electrodes is in the form of a composite containing the material or materials of electrodes mixed with the electrolytic composition and carbon in form divided, such as Shawinigan black, Ketjenblack, graphite.

io Another application of the invention is that of supercapacities, in which at least one electrode is made of high surface carbon specific and the electrical energy is stored by the capacity of the double layer between the material carbon and the electrolyte. In a preferred embodiment, both electrodes are symmetrically made based on high surface area carbon, And this material is used as a composite in admixture with the electrolyte. A
Another possibility is to use an electrode material containing at least one minus one polymer having conjugated double bonds. In a preferred mode of embodiment, the conjugated polymer may have three degrees of oxidation, obtained by Reduction (called doping "n") concomitant with an injection of electrons and cations, or by oxidation (called doping "p") concomitant with electron extraction and injection of anions, from the neutral form. Polymers based on phenyl-3-thiophene, in especially poly (4-fluorophenyl-3-thiophene) are particularly preferred.

-9 The examples provided below are to illustrate ways of preferred embodiments of the present invention, and should in no way case be considered to limit the scope of the invention.

Example 1 Trifluoroethanol (18.2 mL, 25 mml) is dissolved in 100 mL of ether and this solution is added to 7 g of sodium hydride. When the generation of gas stopped, the solution is centrifuged, and clear supernatant liquid is added at 0 C to 35 g (25 mmol) dimethylsulfamoyl chloride dissolved in 100 mL of dry ether under agitation. A white precipitate of sodium chloride is then formed and the reaction is complete after 2 hours. The resulting suspension is filtered and the ether is evaporated at using a rotary evaporator. The residue is placed in 50 ml of dichloromethane and washed with an aqueous solution of 10% hydrochloric acid. The organic phase is then separated and dried with anhydrous magnesium sulphate. The product resulting the trifluoroethyl N, N dimethylsulfamate is distilled under reduced pressure.
NMR: '9F:
triplet S = 74.7 ppm, JHF = 8.1 Hz; H: quadruplet S = 4.66 (2H), singlet S =
3.6 (6H).
Conductivity of lithium salts of bis (trifluoromethanesulfonimide) (CF3SO2) 2NLi in solution in this solvent is given according to the concentration in Table 1.

Table 1 molality (mol.kg "') conductivity K S.cm' 0.265 0.634 0.506 0.922 0.898 1.025 1,160 0.796

-10-The domain of electrochemical stability was measured by voltammetry cyclic on a platinum microelectrode 15 m in diameter for exploration of the anode potentials, nickel for cathode potentials. The domain of stability is 0 to 5.2 V vs. Li + / Li. The variation of the conductivity in function of the temperature is given in the following Table 2 for a concentration of mol.kg.

Table 2 T (C) KSP (S.cm ') T (C) KSp (S.cm') 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 2 107.4 ml of dimethylsulfamoyl chloride are refluxed under nitrogen in the presence of 70 g of potassium fluoride and 10 ml of water. The mixture is refoidi and extracted with dichloromethane, dried with magnesium sulphate and distilled.

The compound (CH3) 2NSO2F obtained has a dielectric constant greater than 30. The stability range as determined by cyclic voltammetry is 5 V
vs.
Li + / Li. The lithium salt of fluorosulfonimide (FSO2) 2NLi is soluble in this medium and its conductivity at 25 C is greater than 1 mScm "'in the range of concentration 0.5 to 1 mole.kg '.

Example 3

-11-To 6.3 mL of 1,1,1, -3,3,3, -hexafluoropropanol in 25 mL of ether anhydrous are added 1.6 g of sodium hydride. When the release Hydrogen a stopped, the solution is centrifuged, and the supernatant is added 8.6 g (60 mml) of dimethylsulfamoyl chloride dissolved in 25 ml of dry ether at 0 ° C.
agitation.

A white precipitate of sodium chloride is then formed and the reaction is complete after 2 hours. The resulting suspension is filtered and the ether is evaporated at using a Rotary evaporator. The residue is placed in 20 mL of dichloromethane and washed with a 10% aqueous solution of hydrochloric acid. The organic phase is then separated and dried with anhydrous magnesium sulphate. The resulting product, the Hexafluoropropyl N, N-dimethylsulfamate is obtained by evaporation of dichloromethane and purified by distillation under reduced pressure. Her constant dielectric is greater than 20, and the salt solutions of bis (trifluoromethanesulfonimide) (NCzHs) 4 (CF3SO2) 2N in solution in this solvent is between 5 x 10-4 and 2 x 10-3 Scm 'at 25 C in the concentration range 0.2 to 1 mole.kg.

Example 4 To 15.76 g of ethylmethylsulfamoyl chloride dissolved in 100 ml of tetrahydrofuran are added 4.2 g of cyanamide and 11.22 g of diazabicyclo 2,2,2-octane (DABCO). After maintaining stirring for 8 hours at room temperature ordinary, 13 g of oxalyl chloride are added dropwise in 40 ml of tetrahydrofuran Anhydrous. After the end of the evolution of gas (CO + C02), the hydrochloride of DABCO
is filtered off and the filtrate is evaporated under reduced pressure and taken in 50 mL
of acetonitrile to which are added at 0 C 12.2 g of ethylmethylamine. The precipitated

-12-ethylmethylammonium chloride is separated and the solvent is evaporated under empty. The polar compound:

H5C2 -N 11,, N -C2He ~ \

is dissolved in dichloromethane and washed with water containing 2%
acid hydrochloric acid, then 5% sodium bicarbonate. After elimination of dichloromethane, the product is distilled under reduced pressure. This product is a solvent delocalized anion salts, in particular perfluorinated imides.

Example 5 33 g of 1,1-dimethylsulfamide (CH3) 2SO2NH2 and 6 g of sodium hydroxide in 200 ml water are boiled for 2 hours. The product of the reaction, the salt sodium from the bis (dimethylaminosulfonimide), ie, Na [N (SO2N (CH3) z)] is obtained by evaporation of water and purified by recrystallization from ethanol. 25 g of this salt suspension in 100 mL of anhydrous acetonitrile are treated with 9 mL of oxalyl chloride. After the end of reaction, ie, the evolution of gas, the suspension is cooled to 0 C and are added 20.7 mL of diethylamine in 50 mL of acetonitrile. After maintaining the agitation while 4 hours at room temperature, the mixture is filtered and acetonitrile is evaporated under reduced pressure. The resulting liquid is put in solution in the dichloromethane and washed water containing 2% hydrochloric acid, then 5% bicarbonate sodium. The solution is passed over a column of active alumina and the dichloromethane is evaporated under vacuum. The polar solvent:

-13-IHs C2H5 H3C-N ,,, S ~ N -C2H5 CH3 O ~ ~ N -SO2N

is kept anhydrous by addition of lithium hydride.

Example 6 An electrochemical generator consisting of a lithium negative electrode of m on a 10 m nickel support, a composite positive electrode containing 78% in vanadium oxide weight V205, 8% carbon black (Ketjenblack) and 14% of copolymer of vinylidene fluoride and hexafluoropropene on a collector nickel (10 m) was realized. The capacity of the positive electrode thus obtained by spreading from a suspension in cyclohexanone is 2.8 mAh / cm 2.
The electrolyte is consisting of a solution of 0.15 Mkg of Li (CF3SO2) zN in the compound polar of Example 1 in a porous polypropylene separator Celgard type. The generator was cycled over 150 cycles between 1.6 and 3.4V at C / 3.7 while maintaining a ratio capacities charge and discharge equal to 1 and a utilization rate> 75% of 30 cycles. The fall Ohmic remained between 20 and 120 mV.

Example 7 An electrochemical generator of type "rocking chair" was built with two composite electrodes similar to those of Example 6. The material of electrode negative is Li4Ti5O1z lithium and titanium spinel for a capacitance surface of 2.6 mAh.cm z. The material of the positive electrode is lithium cobaltite for a surface capacity of 2.4 mAh.cm z. The electrolyte is constituted in a way similar to that of Example 6 with a solution of 0.15 M.kg.l of Li (CF.sub.3SO.sub.2) Zn in the compound

-14-Polar Example 1 in a porous type polypropylene separator Celgard. The generator was cycled over 500 cycles between 1.5 and 3.3 V at C / 4 now a report of load and discharge capacities equal to 1 and a utilization rate of 80%.

Example 8 An electrochemical supercapacity type generator was built with two symmetrical carbon composites of high surface area (680 mz.g ') and of nickel fibers on a nickel support and bound by a copolymer of fluoride vinylidene and hexafluoropropene. The electrolyte consists of a gel 75% by weight a molar solution of tetraethylammonium fluorosulfonimide (C2H5) 4N [(CF3SO2) 2N] in the same polymer. The capacity of the system as well built is 1.2 Fg 'over 12000 cycles performed between 0 and 2.5 V.

Example 9 A polymer electrolyte was prepared by plasticizing a copolymer of ethylene oxide and allylglycidyl ether containing the lithium salt of dimethylaminosulfonyl trifluoromethanesulfonimide Li [(CH3) zSO2NSO2CF3] in a oxygen ratio of ether functions of the polymer / Li of 14: 1 by the compound polar of Example 5 in a weight ratio of 65:35. This electrolyte has a conductivity of 10-4 Scm 'at 25 C and a range of electrochemical stability of 0 to 4V
vs. Li + / Li. The plasticizer has no appreciable vapor pressure in below 120 C. This electrolyte can be crosslinked by a free radical source to give elastomers of good mechanical strength.

Although the present invention has been described using implementations specific, it is understood that several variations and modifications may add to

-15-implemented, and the present application is intended to cover such changes, uses or adaptations of the present invention according to, in general, the principles of invention and including any variation of the present description which will become known or Convention in the field of activity in which this invention, and which can be applied to the essential elements mentioned above, in agreement with the scope following ones.

Claims (17)

1. A polar aprotic compound having solvent properties and responding to the general formula:

R1R2NX (Z) R7 in which X = C or SO;
Z = O, NSO2NR3R4 or NCN;

R1 and R2 are the same or different and represent C1-18alkyl, C1-18 oxaalkyl, C1-18 alkylene or C1-18oxaalkylene;

R3 and R4 are the same or different and represent C1-18alkyl or C1-18 oxaalkyl;
R7 is an RF group, an RF moiety CH2O-, (RF) 2CHO- or (RF CH2) 2N-;

RF is a fluorine atom, a C1-4alkyl, C1-4oxaalkyl or C1-4azaalkyle, with the restrictions that:

1) if Z = O, then RF is a fluorine atom, a C1-4oxaalkyl group or C1-4azaalkyle; and 2) if Z = O and X = SO, then RF is a fluorine atom or a group azaalkyl. The polar aprotic compound according to claim 1 wherein the C1-4alkyl, C1-4oxaalkyl or C1-4azaalkyl group in the definition of R
F is essentially fluorinated. 3. Electrolytic composition comprising at least one solvent, a soluble salt in the solvent, and at least one polymer, the solvent is an aprotic compound polar responding to the general formula:

R1R2NX (Z) R7 in which X = C or SO;

Z = O, NSO2NR3R4 or NCN;

R1 and R2 are the same or different and represent C1-18alkyl, C1-18 oxaalkyl, C1-18 alkylene or C1-18oxaalkylene;

R3 to R6 are the same or different and represent C1-18alkyl or C1-18 oxaalkyl;

R7 is an RF group, an RF group CH2O-, (RF) 2CHO-, (RF CH2) 2N- or NR5R6;

RF is a fluorine atom, a C1-4alkyl, C1-4oxaalkyl or C1-4azaalkyle, with the restrictions that:

1) if Z = O, then RF is a fluorine atom, a C1-4oxaalkyl group or C1-4azaalkyle; and 2) if Z = O and X = SO, then RF is a fluorine atom or a group azaalkyl. The electrolytic composition of claim 3 wherein an anion of soluble salt is selected from I-, ClO4-, BF4-, PF6-, AsF6-, SbF6-, RFSO3-, XSO2NSO2X'-, (XSO2) (X'SO2) (Y) C-, anions derived from 4,5-dicyano-1,2,3-triazole, 3,5-dicyano-1,2,3-triazole, bis (RF) -1,2,4-triazole, tricyanomethane, pentacyanocyclopentadiene, pentakis (trifluoromethyl) cyclopentadiene, RF SO2NCN-, C (CN) 3-, RF SO2C (CN) 2-and their mixtures, in which, X and X 'are selected from RF, RF CH2O-, (RF) 2CHO-, (RF CH2) 2N-, and R8, R9R10N-, with the proviso that at least one X or X 'is RF, RF CH2O-, (RF) 2CHO-, or (RF CH2) 2N-;

- Y = RF, RF SO2 or CN;

- RF is as previously defined and may be part of a chain macromolecular; and - R8 to R10 are identical or different, and represent C1-18alkyl or C1-18 oxaalkyl, and R8-R10 are possibly part of a chain macromolecular. Electrolytic composition according to claim 3 or 4, characterized in that that a cation of the soluble salt is selected from cations derived from metals alkali, alkaline earth metals and organic cations of the "onium" type, the cation organic onium compounds are chosen from ammoniums, imidazoliums, of the sulfoniums, phosphoniums, oxoniums and mixtures thereof. Electrolytic composition according to claim 5, characterized in that the cation is at least partly lithium. Electrolytic composition according to claim 3, characterized in that what comprises, in addition to the polar compound, a co-solvent. Electrolytic composition according to claim 7, characterized in that the co-solvent is aprotic and polar, and includes the di-alkyl ethers of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycols; the esters, in particular those of carbonic acid, linear or cyclic such as dimethyl carbonate, a methyl ethyl carbonate, a diethyl carbonate, an ethylene carbonate, a carbonate propylene; esters such as gamma-butyrolactone, nitriles glutaronitrile, 1,2,6-tricyanohexane as well as mixtures of the aforementioned compounds, and amides such as dimethylformamide, N-methylpyrrolidinone. Electrolytic composition according to claim 8, characterized in that the polyethylene glycol mass is between 400 and 2000. 10. Electrolytic composition according to claim 3 characterized in that the polymer is selected from those whose monomeric units are derived from oxide ethylene, a propylene oxide, an epichlorohydrin, an epifluorohydrin, of trifluoroepoxypropane, acrylonitrile, methyl methacrylate, fluoride vinylidene, an N-vinylpyrolidinone, hexafluoropropene, each in form of homo- or co-polymer and mixtures thereof. Electrolytic composition according to claim 8, characterized in that it is plasticized or in gel form. Electrolytic composition according to claim 9, characterized in that at at least one of the polymers is a polyelectrolyte incorporating in the weft macromolecular anions type of those with delocalized charge. 13. Electrochemical generator characterized in that it uses a composition electrolyte as defined in claim 3 as a electrolyte. 14. Electrochemical generator according to claim 13, characterized in that the negative electrode contains metallic lithium, one of its alloys, a compound carbon insertion, low insertion potential oxide, nitride double of one transition metal and lithium or their mixtures. The electrochemical generator of claim 14 wherein the carbon insertion compound is petroleum coke or graphite, and in which the oxide with low insertion potential is a titanium spinel. 16. Electrochemical generator according to claim 14 characterized in that the positive electrode contains vanadium oxide, mixed oxide of lithium and vanadium, a double oxide of cobalt and lithium, a manganese spinel;
a double phosphate structure olivine or Nasicon, a salt of the acid rhodizonic, a polydisulphide derived from the oxidation of dimercaptoethane, 2,5-dimercapto 1,3,4 thiadiazole, 2,5-dimercapto-1,3,4-oxadiazole, 1,2-dimercaptocyclobutene-3,4-dione or their mixtures. 17. Supercapacity type electrical energy storage system characterized in that it uses as electrolyte an electrolytic composition such that defined in claim 3.