FR2606220A1 - Materials having proton conduction (by protons or by both protons and alkaline ions), process for their preparation and their applications - Google Patents

Abstract

The invention relates to an anhydrous macromolecular material having proton conduction, characterised in that it consists essentially of a solid solution of at least one acid salt of a strong acid derived from an alkaline cation of formula: [M<->]x[HyXO4]<x-> in which: M<+> is an alkali metal ion or the ammonium ion X is a sulphur, selenium or phosphorus atom x and y are non-zero indices consisting of whole numbers which can take values such as (x=1, y=1), (x=2, y=1) or (x=1, y=2), dissolved in a polymer - homo- and/or copolymer - having linear or crosslinked chains containing hetero atoms capable of forming complexes with the released proton species or proton species which can be released by the acid salt of a strong acid. Use of these macromolecular materials according to the invention as electrolytes, electrodes or both, in electrochemical generators.

Description

PROTONIC CONDUCTION MATERIALS
(BY PROTONS OR BOTH BY PROTONS AND ALKALINE IONS)
THEIR PREPARATION PROCESS AND THEIR APPLICATIONS
The subject of the invention is new materials with proton conduction (by protons or both by protons and alkaline ions) hereinafter referred to as proton conduction, capable of being used in particular as electrolytes and / or generator electrodes. It is understood that for the purposes of description, the term "alkali ion" includes ammonium ion. The set of conductive species will be designated in the remainder of the description by the expression “proton species”.

The invention also relates in particular to new electrochemical generators of the type of those in which the chemical reaction at the origin of the production of current involves the transfer, by proton conduction via an electrolyte, of protons or d. ions coming from a negative electrode or "source" of such protons or ions, being at a higher chemical potential, to a positive electrode or "sink" for the hydrogen atom, and being at a lower chemical potential .

The invention also relates to such generators in which the negative electrode is capable of supplying a proton or an alkaline ion at its interface with the electrolyte, and the positive electrode is capable of incorporating into its molecular or physical structure the insertion compound resulting from the formation of the hydrogen molecule or the alkali metal in contact with the positive electrode.

Until now, the work carried out on the various salts in order to achieve cationic conduction aimed at increasing the mobility of the cation associated with a bulky anion which then played a small part in the conduction. The salts employed were, for example, complex salts of the type mentioned in US Pat. No. 4,573,768.

In addition, the work has been aimed at the study of conduction materials, made from polymer complexes of the type M + X or M + is an alkali ion of the type Li, Na +, NH4 and X is a strong acid anion. works are the subject of patent FR.78.32.977.

The object of the invention is to provide conduction materials simultaneously bringing together protons or proton species behaving like protons and / or alkali ions. In the materials according to the invention, conduction is effected by protons, or by alkali metal ions and protons, in conjugation, via the anionic chain.

Proton conduction materials capable of being used at ambient temperature are hydrates, either crystalline of the hydrogen uranium - phosphate (HUO 2 PO 44H 2 O) type, or ion exchange resins, formed by polymers containing ionophore groups of the acid type.

These different materials operate in a hydrated medium and consequently their stability range is limited by that of the water of solvation.

In the absence of moisture, there is no appreciable conductivity.

In addition, these materials are incompatible with vacuum, which can present drawbacks, in particular for shaping, or for certain types of application.

In addition, the existence of protons solvated by water has the drawback of causing corrosion phenomena.

The object of the invention is to provide materials with proton conduction exhibiting satisfactory conductivity at room temperature.

The aim of the invention is to provide materials with anhydrous proton conduction in which there is no corrosion phenomenon and consequently whose properties are not affected over time.

The object of the invention is to provide materials with proton conduction which are stable with respect to air and which are also compatible with vacuum.

Another object of the invention is to provide proton conduction materials that are inexpensive and easy to use.

The object of the invention is also to propose materials with proton conduction capable of being used in the constitution of “all solid” generators, in which adequate maintenance of the electrical contacts between the electrolyte and the electrodes is achieved.
Another aspect of the invention is to provide proton conduction materials capable of being used in the constitution of all-solid-state generators, without there being, during use, a polarization liable to cause variations. important of the charging and discharging characteristics of the generator
The aim of the invention is, in particular, to provide electrochemical generators, preferably rechargeable, the conduction of which is proton capable of operating satisfactorily at room temperature, of which all the components are and remain in the solid state during operation, stable. vis-à-vis air, and in which any changes in volume can be compensated relatively easily and in which the risks of breaking contact between the electrodes and the electrolyte are considerably reduced, if not eliminated.

In particular, the use of the proton conduction macromolecular materials of the invention allows proton conduction according to the invention while maintaining good thermal stability around 100 ° C.

The anhydrous proton conduction macromolecular material according to the invention is characterized in that it is essentially constituted by a solid solution of at least one acidic salt of a strong acid derived from an alkaline cation, of formula: [M] x CH X041 in which is an alkaline ion, in particular Na +, Li +, K +, Cs +, or the ammonium ion NH4
X is a sulfur, phosphorus or selenium atom x and y are non-zero indices made up of whole numbers, which can take the values (x = 1, y = 1), (x = 2, y = i) or (x = 1, y = 2).

completely dissolved in a polymer - homo and / or copolymer - with linear or crosslinked chains, containing heteroatoms, in particular oxygen and / or nitrogen, capable of forming complexes with the proton species released or releasable by the strong acid salt of strong acid.

The acidic salts of strong acids used in a preferred embodiment according to the invention are MHSO4 hydrogen sulphate salts, or MH2pO4 dihydrogen phosphate salts. The simple acid salts used in the invention derive from very corrosive acids when they are not in the form of salt at least in part. The use of the acid salts according to the invention is therefore particularly advantageous in that these acid salts do not present problems of degradation with respect to the polymers and of corrosion with respect to the other elements of the generator. Another advantage resulting from the salt form of strong acids results in obtaining acidic salts which are simple conductors, unlike the corresponding nonacidic salts which are very poor conductors.

The elimination of the corrosion problems in the proton conduction macromolecular materials according to the invention makes it possible to extend the choice of polymers and allows the use of these materials not limited in time.

The compatibility of the acid salt of strong acid and of the macromolecular material corresponds in particular to the stability of the complex formed between the macromolecular material and the acid salt of strong acid; in other words, this compatibility can be defined by the fact that the acid salt of the strong acid is not capable of causing chain cleavages of the macromolecular material and therefore is not capable of reducing the mass molecular weight of the macromolecular material used. According to a particularly advantageous aspect of the invention, the acid salts used do not lead to the degradation of the macromolecular material.

Linear chains are defined as chains in which there is no atom forming a point of convergence of more than two macromolecular chains.

Crosslinked chains are defined as chains in which there are atoms forming a point of convergence of more than two macromolecular chains.

According to a preferred embodiment of the invention, the macromolecular materials are characterized in that they are formed from a solid solution of at least one acid salt of strong acid of formula MHS04 in which
M is an alkaline atom in particular of the Li, Na, K, Cs or ammonium NH4 type in an elastic and plastic solid macromolecular material, mainly amorphous in nature, consisting in part or in full of homo and / or copolymers, å linear or crosslinked chains.

In preferred embodiments according to the invention, the compounds LiHSO4, NaHSO4, NH4HSO4 have been used.

The acid salt of strong acid MHS04 is advantageously used in the invention, because the presence of anionic chains HS04 in the macromolecular material with proton conduction according to the invention makes it possible to considerably reduce the number of anions transported, the groups, ho04 being strongly associated by hydrogen bonds. Thus H is carried by the anion HS04 and migrates in the form of H + along the anionic chain.

dans laquelle R1 représente un atome d'hydrogène ou l'un des groupes Ra, CH,-O-R , -CH-O-Re-Ra, -CH2-N=(CH3)2 avec
- Ra représentant un radical alcoyle ou cycloalcoyle comportant 1 à 12 atomes de carbone, et de préférence 1 à 4 atomes de carbone,
- Re représentant un radical polyether de formule générale

p ayant une valeur de O à 10
soit par la formule suivante

dans laquelle R2 représente H, Ra, -Re-Ra, avec Ra et Re ayant respectivement l'une des significations sus-indiquées ou encore la polyethyleneimine (PEI)
soit par la formule suivante

dans laquelle Ra et Re ont respectivement l'une des significations sus-indiquées
Le susdit matériau macromoléculaire est soit un copolymère de l'oxyde d'éthylène et d'un deuxième motif choisi parmi les étheroxydes de formule

dans laquelle R3 représente
soit un radical alcoyle Ra1, Ra1 comprenant de 1 à 12 atomes de carbone et de préférence de 1 à 4 atomes de carbone,
soit un radical CH2 - 0 - Re - Ra1, dans lequel Ra1 a la signification indiquée ci-dessus et Re représente un radical polyether de formule
- (CH2 - CH2 - O)p, p variant de O à 10, et la proportion du deuxième motif par rapport à l'oxyde d'éthylène, est choisie de telle sorte que le matériau macromoléculaire ne présente pas de cristallinité ou une cristallinité inférieure à environ 40% aux températures d'utilisation, tout en présentant une bonne conductivité
Le susdit matériau macromoléculaire est soit un polyamide, homopolymère ou copolymère et dérive d'un ou plusieurs motifs monomères représenté par les formules suivantes

The aforesaid macromolecular material derives from one or more monomer units of the type shown
- or by the following formula

in which R1 represents a hydrogen atom or one of the groups Ra, CH, -OR, -CH-O-Re-Ra, -CH2-N = (CH3) 2 with
- Ra representing an alkyl or cycloalkyl radical comprising 1 to 12 carbon atoms, and preferably 1 to 4 carbon atoms,
- Re representing a polyether radical of general formula

p having a value of 0 to 10
either by the following formula

in which R2 represents H, Ra, -Re-Ra, with Ra and Re respectively having one of the meanings indicated above or else polyethyleneimine (PEI)
either by the following formula

in which Ra and Re respectively have one of the meanings indicated above
The aforesaid macromolecular material is either a copolymer of ethylene oxide and of a second unit chosen from the etheroxides of formula

in which R3 represents
either an alkyl radical Ra1, Ra1 comprising from 1 to 12 carbon atoms and preferably from 1 to 4 carbon atoms,
or a CH2 - 0 - Re - Ra1 radical, in which Ra1 has the meaning indicated above and Re represents a polyether radical of formula
- (CH2 - CH2 - O) p, p varying from 0 to 10, and the proportion of the second unit relative to the ethylene oxide, is chosen such that the macromolecular material does not exhibit crystallinity or crystallinity less than about 40% at operating temperatures, while exhibiting good conductivity
The aforesaid macromolecular material is either a polyamide, homopolymer or copolymer and is derived from one or more monomer units represented by the following formulas

dans lesquelles
- R, R', R" représentent l'hydrogène, ou un radical alcoyle monovalent ou oxaalcoyle monovalent, de 1 à 12 atomes de carbone et de préférence de 1 à 4 atomes de carbone, ou un radical aryle monovalent de 6 à 12 atomes de carbone,
- Q, QI représentent un radical alcoyle divalent ou oxaalcoyle divalent, de 1 à 12 atomes de carbone et de préférence de 1 à 4 atomes de carbone, ou un radical aryle divalent de 6 à 12 atomes de carbone
Le susdit matériau macromoléculaire est soit un polyester homopolymère ou dérive d'un ou plusieurs motifs monomères représenté par les formules suivantes

dans lesquelles R ET R' représentent l'hydrogène, ou un radical alcoyle monovalent ou oxaalcoyle monovalent, de 1 à 12 atomes de carbone et de préférence de 1 à 4 atomes de carbone, ou un radical aryle monovalent de 6 à 12 atomes de carbone
Le susdit matériau macromoléculaire est soit une polysulfone homopolymère ou copolymère et dérive d'un ou plusieurs motifs monomères représenté par la formule suivante

dans laquelle R représente l'hydrogène, ou un radical alcoyle monovalent ou oxaalcoyle monovalent, de 1 à 12 atomes de carbone et de préférence de 1 à 4 atomes de carbone, ou un radical aryle monovalent de 6 à 12 atomes de carbone
Le susdit matériau macromoléculaire est soit une polyamine homopolymère ou copolymère et dérive d'un ou plusieurs motifs monomères représenté par la formule suivante

dans lesquelles R représente l'hydrogène, un radical alcoyle monovalent ou oxaalcoyle monovalent, de 1 à l2 atomes de carbone, de préférence de 1 à 4 atomes de carbone, ou un radical aryle monovalent de 6 à 12 atomes de carbone,
- Q représente un radical alcoyle monovalent ou oxaalcoyle divalent, de 1 à 12 atomes de carbone, de préférence de 1 à 4 atomes de carbone, ou un radical aryle divalent de 6 à 12 atomes de carbone.

in which
- R, R ', R "represent hydrogen, or a monovalent alkyl or monovalent oxaalcoyl radical, from 1 to 12 carbon atoms and preferably from 1 to 4 carbon atoms, or a monovalent aryl radical of 6 to 12 atoms of carbon,
- Q, QI represent a divalent alkyl or divalent oxaalcoyl radical, from 1 to 12 carbon atoms and preferably from 1 to 4 carbon atoms, or a divalent aryl radical of 6 to 12 carbon atoms
The aforesaid macromolecular material is either a polyester homopolymer or derived from one or more monomer units represented by the following formulas

in which R AND R 'represent hydrogen, or a monovalent alkyl or monovalent oxaalcoyl radical, of 1 to 12 carbon atoms and preferably of 1 to 4 carbon atoms, or a monovalent aryl radical of 6 to 12 carbon atoms
The aforesaid macromolecular material is either a polysulfone homopolymer or a copolymer and is derived from one or more monomer units represented by the following formula

in which R represents hydrogen, or a monovalent alkyl or monovalent oxaalcoyl radical, of 1 to 12 carbon atoms and preferably of 1 to 4 carbon atoms, or a monovalent aryl radical of 6 to 12 carbon atoms
The aforesaid macromolecular material is either a polyamine homopolymer or a copolymer and is derived from one or more monomer units represented by the following formula

in which R represents hydrogen, a monovalent alkyl or monovalent oxaalcoyl radical, of 1 to 12 carbon atoms, preferably 1 to 4 carbon atoms, or a monovalent aryl radical of 6 to 12 carbon atoms,
- Q represents a monovalent alkyl or divalent oxaalcoyl radical, from 1 to 12 carbon atoms, preferably from 1 to 4 carbon atoms, or a divalent aryl radical from 6 to 12 carbon atoms.

The macromolecular materials entering into the constitution of anhydrous ionically conductive macromolecular materials must be compatible with the acid salt of strong acid or the mixture of acid salts of strong acids used.

Thus according to a preferred embodiment of the invention, the macromolecular materials are chosen from those formed from compounds or derivatives of group compounds containing ethylene oxide, etheroxides, polyamides, polyesters, polysulfones , polyamines.

According to another preferred embodiment of the invention, the macromolecular materials are chosen from homo or copolymers with linear chains of the type.
- Polyoxyethylene (POE), of formula (CH2CH20) n, n being an integer chosen such that the molecular mass of the polymer is between 100,000 and 5,000,000
- #oly (ethyleneimine) (PEl), of formula LCH2-CH2-NH), n being an integer chosen such that the molecular mass of the polymer is between 50,000 and 60,000
- Poly- (acrylic acid) (PAA), of formula [CH2CH (COOH)] n 'n being an integer chosen such that the molecular mass of the polymer is between 250,000 and 2,000,000.

- Polyvinylpyrrolidone (PVP)
This is in no way intended to limit the choice of polymers to the group described above. It is understood that other polymers which are satisfactory for carrying out the invention can be used.

The proton conduction macromolecular materials according to the invention are plastic, or even elastic, and have a mainly amorphous character.

The predominantly amorphous character is generally defined as a degree of crystallinity of less than 40% at the temperature of use.

It is preferred for the compounds according to the invention, that they are amorphous or capable of being made amorphous. Depending on the case, they can be elastomeric amorphous or glassy amorphous insofar as the appearance of crystalline zones is avoided at an operating temperature T> Tg (Tg being the glass transition temperature), and this is the case when the material is amorphous elastomer, or at a temperature T <Tg and this is the case of a vitreous amorphous material.

Obtaining macromolecular material with amorphous proton conduction under the aforementioned conditions is a particular advantage according to the invention.

In a preferred embodiment according to the invention, the macromolecular material used to constitute the proton conduction macromolecular material is a mixture of polymers in which one polymer has a basic center and another polymer has an acidic center.

Basic centers and acid centers are defined in the Bronsted sense. They can also be defined as proton acceptor (case of a basic center) or proton donor (case of an acid center).

Thus the POE is proton acceptor, it only has basic "0" centers. the PAA is a proton donor through its acidic center consisting of the OH function of

The mixture produced is such that aeux selected polymers are mixed in proportions such that their reciprocal miscibility capacities are ensured.

The miscibility capacities are respected when a single phase is obtained after completion of the mixture. This single phase corresponds to a mixture of low proportions by weight of polymers of similar molecular masses. Preferably one of the polymers in the blend will not exceed 5% by weight of the other, preferably 3% by weight.

Thus the miscibility of the polymers is achieved in an advantageous manner for certain mixtures mentioned by way of examples, in particular the following mixtures - POE and PAA - PEI and PAA - PVP and PAA.

In a preferred embodiment according to the invention, the P0E, PAA mixture will be used in the POE, E PAA or PAA, E POE forms with E not exceeding 3% by weight.

An advantage of the use of these polymer mixtures results in the improvement of the stability of the macromolecular materials in their amorphous state as defined and makes it possible to significantly reduce the crystallization which is detrimental to good conduction.

the proton conduction macromolecular materials according to the invention can advantageously be thermoformable in the case where they consist essentially of linear chains.

The macromolecular materials according to the invention are both plastic and elastic, even when they consist in part of crosslinked chains. These macromolecular materials then exhibit excellent mechanical properties, in particular an inability to creep, that is to say an absence of residual deformation.

Proton conduction macromolecular materials easily lend themselves to the manufacture of thin films, for example by hot rolling, or by depositing the solutions they form in organic solvents or solutions of their constituents on a support by evaporation of the solvent. base, namely macromolecular material and the acid salt of the anhydrous acid in a common solvent, such as methanol or acetonitrile.

Preferably, use is naturally made of macromolecular materials having a sufficient molecular mass to exhibit the required plasticity character.
These properties are generally acquired for molecular weights greater than 50,000, it being understood that this value is only indicative.

Preferably, the molecular weight of the materials according to the invention is between 100,000 and 5,000,000.

A preferred category of anhydrous macromolecular proton conduction materials according to the invention is formed by amorphous elastomers and therefore which belong to the general class defined above and which are derived from monomers of the type defined in formulas (I) to (XIV) above.

These macromolecular materials are in particular the subject of French patent applications no.78.32973 filed on November 22, 1978, and no.83.09886 filed on 15
June 1. These patent applications are cited in the present invention by reference.

Another category of anhydrous proton conduction macromolecular materials consists of those in which the molecular material is a crosslinked polymer, consisting for example of a copolymer of methylacrylamide and of methylene (bisacyclamide).

Advantageously, the aforementioned crosslinked polymer exhibits a crosslinking rate of approximately 1% to eniro 10%, it being recalled that the degree of crosslinking is defined by the ratio of the number of units of polyfunctional mono Qrs to number of monofunctional monomer units.

The macromolecular material according to the invention preferably contains a proportion of monomer units of the polymer of the same order of magnitude as the proportion of the acid salt. It is one of the advantages of the invention to be able to use a large proportion of salt without losing the qualities of elasticity of the macromolecular material.

According to a preferred embodiment of the invention, the ratio between the number of monomer units of the macromolecular material and the number of protons and / or alkali metal ions released by the acid salt is equal to or greater than approximately 0.5 and is advantageously from about 0.5 to about 20, preferably between 1 and 16.

In the case where the macromolecular material is a polyether, the ratio between the oxygen number of the polymer and the number of ammonium ions or alkaline ions fibers by the acid salt (O / M) is included in virion 1 a ~ 6.

Advantageously, the report. from the number of carbon atoms to the number of heteroatoms in the macromolecular material itself is as low as possible due to their solvating action against the ions of the salt.

In general, the anhydrous macromolecular materials with proton conduction advantageous according to the Jvent.ion are those which have a conductivity greater than or equal to about 10 5n 1cm 1, at ambient time, and which moreover are stable up to 'at temperatures around 100 C.

To prepare the anhydrous proton conduction macromolecular materials according to the invention; one can carry out a mechanical mixing of the constituents, that is to say of the macromolecular material and the salt. The dissolution takes place at the melting temperature of the macromolecular material in a sealed tube.

Another method consists of dissolving the macromolecular material and the acid salt in a common solvent. In a preferred aspect of the invention, this common solvent is limited, for reasons of solubility of MHSO4, to water and optionally to methanol or else to the water / methanol mixture.

This second method is best suited to the ease of forming complexes in the form of films; the solvent is evaporated by the combined action of heat and vacuum.

A third method consists of dissolving the polymer and the non-acidic salt in a common anhydrous organic solvent and then adding the quantity of acid necessary to obtain the acid salt. The solvent is then rapidly evaporated. Thus, the POE mixture, (NH4) 2SO4 can be dissolved in CH2Cl2 or in CH3CN and H2504 is added to the solution to form NH4HSO4.

During operations, special care is taken to control the complete dehydration of the material. These checks are made by means of infrared spectroscopy and by conductivity measurements by an apparatus allowing the sample to be subjected under vacuum to temperature cycles and to achieve the intrinsic conduction properties of the material.
The relative proportions of the basic constituents capable of being used in this process correspond substantially to those which are desired in the final product. Preferably, one mole of acid salt will be used per kg of macromolecular material1, the proportions used, however, not exceeding those corresponding to the limits of solubility of the ionic compound in the macromolecular material.

Some of the corresponding monomers or polymers are commercially available or can be made according to known techniques.

The macromolecular materials can be obtained by homopolymerization or copolymerization of the corresponding monomers according to known techniques, for example using catalysts, such as those described in US Patents Nos. 3,728,320 and 3,728,321.

The other materials of the aforesaid category are accessible by synthetic routes described for example in the "Encyclopedia of Polymer Science and
Technology ", vol. 14, p. 504, edited by Interscience
Publischers, New York, or in U.S. Patent No. 2,311,567.

To prepare the anhydrous macromolecular proton conduction materials according to the invention, in which the macromolecular material is crosslinked, it is possible to have recourse to a polymerization of the monomer in the presence of the stoichiometric amount of acid salt, by heating to a temperature corresponding to the decomposition temperature of the radical initiator.

In order to prepare the electrolyte itself, with a view to its incorporation into an electrochemical generator, one or the other of the processes already mentioned above can in particular be implemented for the manufacture of the natiere itself.

Starting, for example, with a solution of the macromolecular materials and the salt of the chosen acid, the latter can be poured onto a plate, the solvent then being removed by evaporation, in an oven, for example at a temperature of 1 'order of 100 C
After drying, a film is obtained which can be detached from the support, the latter being advantageously for this purpose made of a non-adherent material, such as polytetrafluoroethylene.

It goes without saying that the thickness of the thin film obtained will depend on the amount of raw material used in the solution.

The support in question can also be formed by one of the electrodes, for example the positive (Q the negative), with which the electrolyte thus formed must be associated in the final generator.

The negative can in turn be achieved by casting on the free surface of the electrolyte.

It goes without saying that any other method of producing a generator element can be envisaged.

It is also possible to proceed by simply stacking thin films of the electrode materials on the two opposite sides of a previously formed electrolyte film.

In general, and more particularly in "all solid" generators of the rechargeable secondary type, one can have recourse to the constitution of the negative, to any compound capable of releasing a proton or an ion at its interface with the electrolyte. solid.

In accordance with an additional predefined characteristic of the invention, at least one of the electrodes is modified by incorporation into its mass of a material formed from a solid solution of the same nature as that of the electrolyte, preferably the same. .

According to a first variant, the electrode produced is the positive electrode, that is to say the electrode for which a reduction reaction takes place when the generator is discharged. This electrode is preferably (constituted by a mixture of an electrochemically active material chosen from MonO 2, CrO 2, a quinone in particular tetrafluoroquinone and of a proton conduction macromolecular material as defined above and optionally of a small percentage of black from carbc # ne3 preferably acetylene black.

According to another variant of the invention, the electrode produced is the negative electrode, that is to say the electrode at which the oxidation reaction takes place when the generator is discharged. In this case, the electrode is preferably constituted by an agglomerate of
TiH2, VH #, FeTi, LaNi5, PdHx, x is a stoe chiometr # qb # e coefficient ranging from O to 1, TiHX, x ranging from O to 2, PtHx, F. ranging from O to 0.1, hydroquinone in particular tetramethylhydroquinone and electrolyte consisting of a proton conduction macromolecular material as defined above, and optionally of a small percentage of carbon black.

These electrodes are particularly suitable for the formation of a generator electrode of the all-solid type ", the electrode thus formed being itself capable, thanks to the plasticity, which is then conferred on it by its macromolecular component, of better adapting to the conditions. volume variations to which it itself and possibly other constituents of the generators are liable to give rise during operation of the generator, whether during charging or discharging, in the case of a generator, whether during charging or discharge, in the case of a secondary generator. Similarly, electrodes are obtained, the surfaces of which have qualities of adhesion and adaptation which are also improved, for example to the surface of the solid electrolyte which may be associated with it .

this is even more particularly so when the macromolecular material is chosen from those which still exhibit, in addition to the aforementioned plasticity, elastic properties allowing the entire electrode to correct itself, at least in part, the variations in volume. that its own active material content may undergo during operation of the generator.

In addition, the incorporation of the solid solution with proton conduction in the mass of the electrode has the effect of extending the electrochemical reactions in the whole mass of the electrode at the level of the grains or particles of the active material, as opposed to conventional generators in which the electrochemical roots are essentially limited to the interfaces between electrolyte and electrodes.

Improved ionic charge transfers from the electrolyte to the electrodes can lead to a relative lowering of the generator operating temperature -
Preferably, the particle size of the particles of active material, and where appropriate, of the auxiliary inert electron conductor (s) and optionally other fillers is between about 0.1 and about 300, for example from 10 to 100.

In the case of an active material whose own ionic conduction is relatively low, it may be advantageous to reduce the above-indicated particle sizes to lower values.

It may be noted that the incorporated solid solution also plays a role of binder with regard to the other constituents of the electrolyte.

The agglomeration in a composite mass of the aforesaid solid solution and of the other constituents of the electrode is also particularly advantageous in the case (> ú uses electrode materials having mechanical properties making them poorly suitable for use. form in determined volumes. This is, for example, the case with the electrode material consisting of
TiH2, which inherently is a brittle and brittle material, difficult to form into thin films.

The proportions of solid solution and of electrode material can vary widely. Preferably, however, the proportion of solid solution does not exceed 25% by weight, although this value is not in itself of critical significance.

The specialist will appreciate, however, that there can be no practical advantage in increasing the proportion of the solid solution in the electrode too much for the simple reason that this results in a concomitant reduction in their electrical capacity.

The electrodes thus modified can be obtained by mixing or intimately kneading the constituents in the pulverulent state, for the electrode material, on the one hand, and of the solid solution, on the other hand.

This operation can, if necessary, be followed by heating to produce better adhesion of the particles of the powdered electrode material within the solution. The electrodes can be obtained by suspending in an organic solvent the material constituted by the aforesaid solid solution or constituents from which they can be formed, the occurrence of the macromolecular material, on the one hand, and the acid salt, d 'on the other hand, and by evaporation of the solvent under conditions similar to those which have already been described in connection with preferred methods of preparation of the electrolyte of the generator according to the invention.

The invention therefore enables the electrodes to be shaped, in particular by casting a suspension as defined above on a support, for example of polytetrafluoroethylene.

The compositions with both electronic and ionic conduction thus obtained, which are suitable for the direct manufacture of electrodes of electric generators, therefore also have the additional advantage of an easy and economical industrial production of electrodes. large area.

Indeed, the plasticity of these compositions allows the shaping, in particular by rolling, of the electrodes in question. A wide variety of configurations can be envisioned.

It is thus possible to produce elements of electrochemical generators by simple stacking of sheets or films, respectively of electrolytes and corresponding electrodes, stacked elements which can optionally be wound in a spiral according to conventional BIFt.hcdes applied for example to manufacturing. dielectric capacitors.

In a particularly advantageous embodiment of the invention, recourse is had to the same solid solution for the constitution of the electrolyte and of the material for incorporation into the electrodes, so as to constitute the elements of generators in which this solid solution extends substantially continuously from the electrolyte towards and in the aforesaid electrolytes, so that contact qualities are established which remain intimate during all the operations carried out by this generator element (charge or discharge) between electrolyte and electrodes.

Such generator elements can be obtained, for example, by forming, in the appropriate order, the successive films of the electrodes, on the one hand, and of the electrolyte, on the other hand, by resorting, for example, to the technique mentioned above consisting of , depending on the case, to form these dandruff
- Either by depositing on a support, preferably non-adherent or on the film previously formed of the electrolyte, of a suspension of the electrode material in a solid solution or of the constituents necessary to obtain it, to what is the manufacture of electrodes
- Or by depositing in particular on a previously formed electrode film of the aforementioned solution alone, followed by evaporation of the solvent, as regards the formation of the electrolyte film.

It goes without saying that generator elements having similar characteristics can also be obtained by resorting to other procedures, in particular by separate formation of the electrode and electrolyte films, these films then being joined together by contact. , for example by hot pressing at a temperature allowing the softening of said solid solution.

The invention therefore allows the manufacture of current generation generators, rechargeable, the various components of which can be extremely thin. By way of example, it is possible in particular to produce any extrelenent nonce generator element using, for example, films or electrolyte sheets having a thickness of between approximately 0.01 and approximately 0.2 mm and sheets or films. of electrodes having thicknesses of 0.1 to 0.5 mm.

It goes without saying that such operations have only an indicative value which should not be interpreted as limiting the scope of the invention. The sets thus strong must naturally, in particular in the case where recourse is had to compounds sensitive to humidity be isolated in perfectly sealed boxes or compartments Where appropriate, the different parts of each generator element (electrolyte and electrodes of opposite signs) are kept tight against each other by means of resilient aryans or elastic, optionally an additional sheet of an elastomer capable of absorbing any variations in volume to which the electrodes may give rise during operation of the generator. In the event that macromolaicular materials of the elastomer type are used for the constitution of the electrolyte and possibly for the incrportation into the electrodes, the use of these resilient means may prove to be unnecessary, to the extent or at least some. essential components of each generator element may be able to compensate for volume changes on their own, due to their ability to expand or compress as appropriate.

He can be. advantageous to provide for the housings dimensions, in particular in the direction of the thickness, corresponding to those of the sums of the thicknesses of these constituents at the normally minimum value that they would take in the absence of compression exerted on the opposite outer faces of the assembly formed by said constituents
Of course, the various elements can be connected in series, with a view to obtaining power generators having high performance.

The invention is applicable in all do hands where the production of electrical energy is sought # whether at the level of microelectronics, very low power generators but capable of operating for long periods of time, such as for example batteries of cardiac pacemakers or pacemakers ", or at the level of electric traction or applications involving large transfers of electric current (flow or storage of energy), for example in the field of curve smoothing. power of power plants (energy storage during off-peak hours and large units of energy fed into the power grid during peak hours).

Another advantage conferred by the use of nacromolecular material with proton conduction according to the invention for the production of electrodes lies in the fact that such electrodes can be associated with any type of solid electrolyte. In addition, they exhibit excellent adhesion properties with respect to current collectors commonly used, for example made of stainless steel.

In the case where this solid electrolyte is a proton conduction wacromolecular material, it is not necessary for its macromolecular material to be ide.nt.ique to that of the electrode.

In particular, a homopolymer or a different copolymer can be envisaged for the electrolyte.

But it is also possible to use solid electrolytes of the beta hydronium alumina type or even proton conduction glasses.

Other applications of proton conduction macromolecular materials according to the invention consist of supercapacitors. A supercapacitor, or supercapacitor, comprises two composite electrodes made by mixing carbon black or carbon fibers with the macromolecular material according to the invention, the electrolyte consisting of the same macromolecular material.

Conduction is carried out via the electrons at the level of the electrodes and mainly via the ions in the electrolytic intermediate layer. This results in an accumulation of charges at the interfaces and the production of current by discharging the capacitor.

The supercapacitors produced according to the invention can be used in particular for protecting the living glories of computers or for supplying various strategic areas in the event of a failure of the usual electrical network.

As another application of proton conduction macromolecular materials, mention may be made of electrochromic display devices which contain a material in which the insertion or deinsertion of the proton species according to the invention (under the effect of the application of a field electrical) corresponds to a color change and the electrolyte, in part or in whole, is the macromolecular conduction material according to the invention.

In general, the anhydrous macromolecular proton conduction materials according to the invention allow the transport of the proton species of the invention which are not solvated by water, the transfer kinetics of which to the electrodes in an electrochemical system is rapid.

The elastic, plastic or elastomeric nature of these compounds makes it possible to ensure good contact with the electrode material, in particular when the transfer of proton species causes variations in volume.

The compatibility of polymer electrolytes with vacuum, due to the non-volatility of the constituents, is a definite advantage since it is possible to deposit or empty the current collectors or the active materials in thin layers according to the techniques commonly used in electronics.

The ionically conductive materials according to the invention are also particularly advantageous insofar as the use of the salts EM +] # LHyXO4] x- considerably reduces the possible degradation vis-à-vis the polymers and the corrosion vis-à-vis the polymers. other elements.

This is particularly important in the case of the application to the electrochromic display. In the case of the use of tungsten oxide for the electochromic display, advantageous results are obtained thanks to the use of the acid salts which reduce the pheonomena ale corrosion troublesome for a prolonged use. For example, this weak degradation is observed for macromolecular materials with proton conduction of the type of those involving a polymer and NH4HSO4 or a polymer and LiESO4, the polymer being able to be advantageously chosen from polyethers and polyacrylic acid (PAA).

An electrochromic cell of interest can be produced by using as proton conduction macromolecular material a material composed of a polymer. of the type of PAA and of a strong acid acid salt of the type of NH # HS04. A preferred embodiment consists of the association of 4 monomer units for one ion originating from the strong acid salt. The electrochromic cell consists of the superposition of an ITO (iridium and tin oxide) electrode with a layer of W03
(tungsten oxide) with a layer of conductive polymer with a thickness of a few microns, a thin layer of iridium oxide and finally a second layer of ITO.

The electrochromic cell thus produced has an advantageous character insofar as the conductive polymer is non-aggressive with respect to the other constituents and that it allows easy shaping insofar as it is in the form of a layer. hard and homogeneous. The shaping results from a simple spraying of the layers of iridium oxide and ITO on the conductive polymer. In particular, it is in the context of this application that the use of the acid salts of the invention is particularly advantageous.

The absence of corrosion, attributable to the use of acid salts and to the anhydrous character of these matraa and the possibility of spreading them easily in the form of thin fibers by conventional polymer techniques allows the construction of low cost miniaturized systems.

The invention will be better understood by virtue of the examples below, implementing the possibilities of application of the invention.

These examples are of course only indicative and non-limiting.

Example 1 - 2.2 g of polyethylene oxide (POE) of molecular mass 5,000,000 and 0.7 g of NH4HSO4 are dissolved respectively in dichloromethane and water, then mixed so as to have a proportion such that P (EO) 8NH4HSO4 is obtained, that is to say an O / NH4 ratio = 8.

The solution is then evaporated under vacuum at 60 ° C. so as to remove all traces of solvent. the film obtained is an elastomer whose conduction under vacuum is -3.10-7@-1cm-1 at 24 C -9.10-5 # -1cm-1 cm-1 at 60 C activation energy: 1.35 ev ( fig I) Example 2 - 4.67 g of POE (5,000,000) and 1.52 g of NH4HSO4 are mechanically mixed, then transferred and sealed in a glass tube under vacuum, so as to have a proportion such that we obtain P (EO) 8NH4HSO4 that is to say O / NH4 = 8.

The whole is brought for three days at a temperature of 140 C. The tube is then immersed in nitrogen.

The plastic obtained exhibits an ionic conduction of -2.10-7 # -1cm-1 at 20 C
-5,7.10-5 # -1 # \ - 1 to 60 C.

Example 3: 2.67 g of polyacrylic acid (PAA) with a molecular mass of 2,000,000, and 1 g of NH4-HSO4 (COOH / NH4 = 4) are dissolved in water.

The solution is evaporated in vacuo at a temperature of 80 C.

The plastic obtained then presents a conduction under vacuum of -6 10-6 # -1cm-1 at 25 C -8.10-4 # -1cm-1 at 85 C activation energy: 1.11 ev (fig 2)
Example 4:
By an equivalent to that of Example 3, it is possible to obtain the complex of global formula
P (AA) 2-NH4HSO4 corresponding to [COOH / NH4] = 2.

This compound is stable up to 160 ° C. under vacuum; its conduction is: -9.10-4 # -1cm-1 to 160 C -4.10-4 # -1cm-1 to 135 C.

Example 5: - 0.49 g of POE (900,000) and 0.68 g of (NH4) 2SO4 to which 0.55 g of H2504 is added, are dissolved in water, then mixed (O / NH4 = 1) . The solution is then evaponated under vacuum after addition of methanol. Conductivity measurements taken in air give values of the order of -1.5.10- 5 # -1 cm- 1 at 25 C, -1.5.10-4 # -14 cm-1 at 50 C
Example 6: - 1.94 g of POE (5,000,000) and 0.73 g of (NH4) 2SO4 to which 0.55 g of H2SO4 is added are dissolved respectively in CHSC12 and in water + CH2C12 (O / NH4 = 4), then iclangês The solution is then evaporated under vacuum. The conductivity is: -2.10-4 # -1 cm- at room temperature of 6.10-3 # -1 cm-1 at 70 C under argon.

Example 7
By one. method equivalent to that of Example 6, the complex of stochiometry O / NH4 = 8 is prepared. In air, the conductivity is -8.10-5 # -1 -1 at cm-1 2.10-4 # -1 cm-1 at 40 C.

Example 8 2.6 g of POE (900,000) and 0.96 of Li2SOe H20 to which 0.74 g of H2SO4 is added are dissolved respectively in a CH3CN / THF mixture and in water. After mixing these two solutions, the mixture is stirred for a few hours, then the solvents are evaporated off in vacuo. The conductivity at ambient temperature is of the order of 10- 4 # -1 1
Example 9: Preparation of proton conduction macromolecular material (by protons or both by protons and alkali ions) xPOE, NH4HS04.

The synthesis of xPOE, NH4HSO4 is carried out from the commercial polychloride of molecular weight 5 106.

(NH4) 2SO4 is dissolved in a mixture of POE and acetonitrile. This solution is then acidified with H2SO in a stoichiometric proportion just before evaporation of the solvent so that the latter is not degraded by the acid.

The results obtained by measuring the conduction reveal, for the solid xPOE, NH4HSO4, a particularly interesting proton conduction.

# = 2.10-4 # -1 cm-1 to 295 K (22 C)
# = 6,5.10-3 # -1 at 345 K (72 C) The activation energy is of the order of 0.6 ev.

Conductivity measurements are made in the absence of water and the decomposition of the complex under the combined action of vacuum and temperature is avoided.

The stability of the compound is measured up to about 100 C.

Infrared spectroscopy confirms the presence of HSO4 ions to the exclusion of SO42- ions and makes it possible to observe the amorphous character of the complex by studying the width of the spectroscopy bands.

The quantitative analysis makes it possible to select preferably the compounds whose values of x are high (x> 8 in particular). These compounds are more stable and their conductivity is close to the aforementioned values.

Claims (8)

1. Anhydrous macromolecular material with proton conduction (by protons or both by protons and alkali ions) characterized in that it consists essentially of a solid solution of at least one acid salt of anhydrous strong acid, derived from an alkaline cation of the formula: [M +] x [HyXO4] x- in which: M + is an alkali ion or the ammonium ion X is a sulfur, selenium or phosphorus atom x and y are non-zero indices made up of integers that can take values such as (x = 1, Y = 1), (x = 2, y = 1) or (x = 1, y = 2). completely dissolved in a polymer-homo and / or copolymer - with linear or crosslinked chains, containing heteroatoms, in particular oxygen and / or nitrogen, and capable of forming with the proton species released or releasable by the acid salt of the acid strong, complexes. 2. proton conduction anhydrous macromolecular material according to claim 1, characterized in that it is formed of a solid solution of at least one acidic salt of anhydrous strong acid, the acid sulfate of formula MHSO4, M being chosen from the group of alkaline compounds or ammonium, completely dissolved in a polymer -homo and / or co-polymer- with linear or crosslinked chains, containing heteroatoms, in particular oxygen and / seen nitrogen likely to form complexes between its heteroatoms and the proton species liberated or releasable by the acid salt of the strong acid. 3. Anhydrous proton conduction macromolecular material according to one of claims 1 or 2, characterized in that the acid salt of anhydrous strong acid is MHSO4, M being chosen from Li, Na, NH4. 4. Proton conduction macromolecular material according to claim 2, characterized in that the nacromolecular material is a solid elastic and plastic material, elastomer, of a prin cipalenent amorphous nature, consisting in part or in whole of homo and / or copolymers to linear chains. 5 Macromolecular anhydrous proton conduction material according to one of claims 1 to 3, characterized in that the macromolecular material is an elastic and plastic solid ma tria, elastomer, å mainly amorphous character, consisting in part or in whole of homo and / or copolymers formed from compounds or derivatives of compounds from the group containing ethylene oxide, etheroxides, polyamides, polyesters, polysulfones, polyimines. 6. Proton conduction anhydrous macromolecular material according to one of claims 1 to 5, characterized in that the macromolecular material is an elastic and plastic, elastomeric solid material, of mainly amorphous character, consisting in part or in whole of 'homo and / or copolymers chosen from - polyoxyethylene (POE) - polyethyleneimine (PEI) - poly- (acrylic acid) (PAA) - polyvinylpyrrolidone (PVP) n being an integer such as the molecular mass of 5,000 .000. 7. Proton conduction anhydrous macromolecular material according to one of claims 1 to 6, characterized in that the macromolecular material is a solid elastic and plastic material, elastomer, mainly amorphous in nature, in the form of a mixture of polymers in which a polymer has a basic proton acceptor center and another polymer has an acidic center proton donor in proportions such that their miscibility capacities are respected :: r 8 Macromolecular anhydrous proton conduction material according to one of claims 1 to 7 because the aforementioned mixture of polymers contains simultaneously PAA and PEI, 9 Macromolecular anhydrous material with proton conduction according to one of claims 1 to 7, characterized in that the aforesaid mixture of polymers simultaneously contains POE and PAA. An electrode structure wherein the electrode material of said structure comprises a proton conduction macromolecular material according to any one of claims 1 to 9. 11. Electrochemical generator, characterized in that its electrolyte consists of the proton conduction macromolecular material according to any one of claims 1 to 9 and in that the negative electrode associated with it consists of a mate. riati capable of providing proton species, and in that the positive electrode which is associated with it is capable of incorporating the proton species. 12. Super capacitor characterized in that it comprises two composite electrodes obtained by mixing carbon black or carbon fibers with the proton conduction macromolecular material according to any one of claims 1 to 9 and as electrolyte, the same macromolecular material. 13 Electrochromic system, characterized in that at least one of the electrodes contains a material in which the insertion or the deinsertion of protons or of icons corresponds to a change of color and of which the electrolyte in part or in whole is the proton conduction macromolecular material according to any one of claims 1 to 9.