NO840236L - POROEST, ELECTRONIC CONDUCTIVE POLYMER MATERIAL, PROCEDURES IN MANUFACTURING THEREOF, AND APPLICATION THEREOF - Google Patents

Description

Technical area

The present invention relates to polypyrrole and copolymers of pyrrole. The invention relates more particularly to electronically conductive materials comprising electropolymerized pyrrole or a copolymer of pyrrole, method for producing electrically conductive polypyrrole or copolymers of pyrrole, and electrochemical cells comprising polymeric electrode devices, the polymeric electrode devices being positive and/or negative and comprising electrically conductive polypyrrole or a copolymer of pyrrole.

The background of the invention

The term polypyrrole denotes polymers containing polymerized pyrrole rings. A pyrrole ring is an unsaturated five-membered ring containing four carbon atoms and one nitrogen atom. Polypyrrole is not limited here to polymers of an unsubstituted pyrrole monomer nor to polymerization at particular sites in the pyrrole rings. A preferred polypyrrole for use according to the present invention is 2,5-polymerized homopolymer of unsubstituted pyrrole. The term copolymer of pyrrole indicates any polymer-containing pyrrole and/or substituted pyrrole monomers and/or one or more other monomers that are copolymerizable with these.

Polypyrrole belongs to the general group of electronically conductive organic polymers and is more particularly one of the group of polymers which under certain conditions can have electrical conductivities above 1 ohm cm which have been developed in recent years. Other well-known members of this group are polyacetylene, poly-p-phenylene, poly-p-phenylene sulfide and poly(2,5 thienylene).

Pyrrole black which is a polymeric powdery material formed by oxidizing pyrrole in a homogeneous solution (e.g.

with H2O2)/ has been known for a number of years. Gardini, Adv. Heterocycl. Chem, 3J5, 67 (1973). An electrochemical method

for the production of polypyrrole in the form of a powdery film on an electrode has been reported. A. Dall' Olio and Associates, Comp. Rend., 4 33, 267c (1968). electrical

polymerization for the preparation of polymer films from pyrrole has been reported. Diaz et al., J. Chem. Soc, Chem. Comm., 635, (1979) (hereafter Diaz (I); Diaz et al., J.Chem. Soc, Chem. Comm, 397, (1980) (hereafter Diaz (II); Diaz, Chemica Scripta, 1/7 , 45, (1981) (hereafter Diaz (III)); and Kanazawa et al., J. Chem. Soc, Chem. Comm., 954 (1979) (hereafter Kanazawa (I)). Electropolymerized polypyrrole from substituted pyrroles has been reported. Diaz (II); Diaz et al., J. Electroanal Chem., 129, 115, (1981) (hereafter Diaz (IV); Diaz et al., J. Electroanal Chem., 130, 181, (1981) (hereafter Diaz ( V)). Copolymer films prepared by electropolymerization of mixtures of pyrrole and substituted pyrrole have also been reported. A mixture of pyrrole and N-methylpyrrole has been polymerized, and it is believed that both monomers are incorporated into the polymer. Diaz (II); Proe. Int. Conf. on Low Dimensional Synthetic Metals Chemica Scripta, 17, 0000,

(1981) (hereafter Diaz (VI)); and Kanazawa and co-workers.

J. Synth Metals, 4, 119, (1981) (hereafter Kanazawa (II)).

Polypyrrole is electronically conductive in the charged or oxidized state (black) and is produced in this state by electropolymerization. When fully reduced to the neutral or discharged state (yellow), it is an electronic insulator. The electropolymerized polypyrrole is produced in the oxidized, i.e. conductive, state and (unlike other conductive polymers, such as polyacetylene) does not require any subsequent chemical or electrochemical treatment to

increasing its conductivity to over 1 ohm "'"cm A counter anion is incorporated into the material during the electropolymerization process to balance the positive charge on the polymer backbone. Díaz (III).

Polypyrrole can be produced in the form of a powder. Gardini, supra. Polypyrrole can also be electropolymerized as a continuous film on electrodes. The highest electronic conductivities reported for the continuous films are of the order of 100 ohm 1cm. Diaz (1); Kanazawa et al., Syn. Metals, 1, 329, (1980) (hereafter Kanazawa (III)). These conductivities can be of lower orders of magnitude depending on the incorporated counter anion.

A large number of counteranions have been used, including BF4~, PFg~, AsF6~, C104~, HS04~, CF3SO3~, Cr^Cgf^SC^", CF3COO", HC204~, Fe(CN)6<3>~ . Diaz (IV); Díaz (VI);

Kanazawa (I); and Noufi et al., J. Electrochem. Soc. 128, 2596, (1981).

N-substituted pyrroles have been polymerized, including methyl, ethyl, n-propyl, n-butyl, isobutyl, or phenyl or substituted phenyl pyrroles. Diaz (IV);

Diaz et al Electrochemical Society Extended Abstracts, Vol.82-1. Abstract No. 617, (1982) (hereafter Diaz (VII)). These materials have been reported to have electronic conductivities that are orders of magnitude lower than polypyrrole as such.. Kanazawa (II) Diaz (VII). It has been reported that 3-substituted pyrroles, such as 3,4-dimethylpyrrole, have been polymerized. Gardini, supra.

The polymers have been prepared to date with non-aqueous solvents, typically acetonitrile, (Diaz (I);

Diaz (II):, and Diaz (VI)), containing a dissolved salt which

gives the counter anion. It is known that the physical properties of the obtained films are sensitive to the formation conditions. For example, small amounts of water in acetonitrile as a solvent will give a film with a smoother surface than that obtained in anhydrous acetonitrile. Diaz (VI). The polypyrrole tetrafluoroborate films produced by Diaz and co-workers are continuous, space-filling and of very poor crystallinity with a density of 1.48 g/cm 3. Kanazawa (III) .

Polypyrrole films are thermally stable at room temperature and insoluble in common solvents Diaz (I); Kanazawa (II); and Tourillon et al., Electrochemical Society ExtendedAbstracts, Vol.82-1, Abstract No. 618, (1982). Polypyrrole in the oxidized state is reported to be chemically stable under ambient conditions in terms of 0^ and humidity, for several months. Diaz et al., J. Electroanal. Chem., 121, 355, (1981) (hereafter Diaz (VIII)); Watanabe et al., Bull. Chem. Soc. Jpn., 54, 2278, (1981). Poly-pyrrole fluoride films have been shown to be unstable under oxidizing conditions, such as potentials above + 0.6 V, (SCÉ), or in the presence of halogens. Bull et al., J. Electro chem. Soc, 129, 1009. (1982).

Polypyrrole can be repeatedly switched between conducting and non-conducting states. Bull et al., supra;

Diaz et al., "Conducting Polymers", Polymer Sci. & Technology, pp. 149 et seq., Plenum Press, N.Y., (19814 (hereafter Diaz (IX)). Rapid change has been reported to

be conditioned by the use of thin films (ie below approx. 0.1^,um), and change is difficult to achieve for thicknesses greater than approx. lyum. Diaz (II), Diaz (IX). It has been shown that although a film may contain BF. -counteranions when formed (ie, in the charged state), BF^ is no longer present in the film when it is in the neutral (ie, the reduced or discharged) state. Díaz (IV). It has been proposed that both the anion and the cation in the electrolyte salt affect ion diffusion by reduction and oxidation of polypyrrole films. Díaz (IV).

Polymers have been prepared with different degrees of oxidation depending on the anion and/or substituents. Most of these materials have oxidation degrees of approx. 0.25 (ie a quarter of the polymer rings are oxidized).

Summary of the invention

The materials according to the invention are electronically conductive materials comprising an electropolymerized polypyrrole or copolymer of pyrrole, and these materials can be porous or non-porous materials in the form of films, powders, dendrite-like materials or in different shapes as desired by pressing powder of the materials according to the invention. These materials are particularly suitable for the formation of positive and/or negative polymeric electrodes for use in electrochemical cells, such as e.g. electrochemical energy storage cells.

The present invention aims to provide a porous, electronically conductive material comprising an electropolymerized polypyrrole or copolymer of pyrrole, the material being characterized by having an apparent density of from 0.01 g/cm 3 and up to the room density for the polypyrrole or copolymer thereof, and a surface area of at least twice the surface area of a smooth film of the space-density material. The invention also provides an electrochemical cell which comprises polymeric electrode devices which are positive and/or negative and which comprise the material according to the invention.

The invention also provides an electronically conductive material comprising electropolymerized polypyrrole or a copolymer of pyrrole, the material containing one or more anions with low mobility which is characterized by an average ion transition number of less than approx. 0.1 for the anions with low mobility during reduction. The invention also provides an electrochemical cell which comprises polymeric electrode devices which are positive and/or negative and which include the material according to the invention.

The invention also aims to provide a method for the production of electronically conductive polypyrrole or copolymers of a pyrrole, where pyrrole or a copolymerizable mixture containing pyrrole is electropolymerized on an electronically conductive surface in an electrolytic bath, and the method is characterized by it includes the steps that

(A) an electronically conductive surface is immersed in an electrolytic bath comprising at least one liquid and at least one

immiscible liquid or gas or finely divided solid particles, in which the pyrrole or the copolymerizable mixture containing a pyrrole is one of the liquids or is dissolved in at least one of the liquids, and

(B) an electric current is passed through the bath at a sufficient voltage to electropolymerize the pyrrole or

the copolymerizable mixture containing a pyrrole, on the electronically conductive surface.

According to a preferred embodiment of this method, an electrolysis bath is used which comprises an aqueous mixture containing pyrrole or a mixture of pyrrole and a copolymerizable monomer and water.

The invention also provides an electrochemical cell which comprises polymeric electrode devices which are positive and/or negative and which comprise an electronically conductive polypyrrole or a copolymer of pyrrole produced by means of the present method.

The invention also provides a method for the production of electronically conductive polypyrrole or a copolymer of pyrrole, and the method is characterized in that it includes the steps that (A) pyrrole or a copolymerizable mixture of a pyrrole is electropolymerized on an electronically conductive surface in an electrolytic bath by (1) immersing an electronically conductive surface in an electrolysis bath comprising (a) an aqueous dispersion of a pyrrole or a mixture of the aqueous dispersion and at least one copolymerizable monomer or (b) a pyrrole or a mixture of a pyrrole and/ or at least one copolymerizable monomer, water and one water-immiscible diluent, (2) the bath is agitated, and (3) an electric current is passed through the bath at a voltage sufficient to electropolymerize the pyrrole or pyrrole mixture and deposit the polymer or copolymer on the electronically conductive surface , and (B) the polymer or copolymer is removed from the conductive surface.

According to a preferred embodiment of this method, an electrolysis bath is used which comprises an aqueous mixture containing pyrrole or a copolymerizable mixture of pyrrole, water and one or more anions with low mobility which are incorporated into the polypyrrole by electropolymerization and which are characterized by an average ionic transmission number of less than 0.1 for the anions with low mobility upon reduction.

The invention also provides an electrochemical cell which comprises polymeric electrode devices which are positive and/or negative and which comprise polypyrrole or a copolymer of pyrrole produced by the above-mentioned method.

The invention also provides a method for the production of electronically conductive polypyrrole or a copolymer of pyrrole, and the method is characterized by the fact that a pyrrole or a copolymerizable mixture containing pyrrole is electropolymerized on an electronically conductive surface in an electrolysis bath at the steps that

(A) an electronically conducting surface is immersed in

an electrolytic bath comprising (i) a pyrrole or a mixture of a pyrrole with a copolymerizable monomer, (ii) one or more anions of low mobility which are incorporated into the polypyrrole or copolymer of pyrrole and which are characterized by an average ionic transfer number of below 0.1 for the low mobility anions during reduction of the polypyrrole or copolymer, and (iii) an organic diluent, and

(B) an electric current is passed through the bath of sufficient voltage to electropolymerize the pyrrole or

the copolymerizable mixture containing pyrrole, on

the electronically conducting surface.

The invention also provides an electrochemical cell which comprises polymeric electrode devices which are positive and/or negative and which comprise polypyrrole or a copolymer of pyrrole produced by the above-mentioned method.

Brief description of the drawings

From the drawings show

Fig. easy side elevation in section through a lithium cell

on a laboratory scale and which shows a particular embodiment of the present invention,

Fig. 2 a side elevation of an electrochemical cell on a laboratory scale and showing another embodiment of the present invention, Fig. 3 a perspective sketch of an electrochemical energy storage cell showing another embodiment of the present invention, Fig. 4 a side elevation in section through it electrochemical cell shown in Fig. 3, Fig. 5 a side elevation in section through an electrochemical energy storage cell showing another embodiment of the present invention, Fig. 6 a side elevation in section through a layered or

electrochemical energy storage cell showing another embodiment of the present invention, and

Fig. 7 is a side elevation in section through a layered or stacked electrochemical energy storage cell showing a further different embodiment of the present invention.

Description of the preferred embodiments

According to a preferred embodiment of the invention, the electrically conductive materials according to the invention contain at least one anion, A, with low mobility which is strongly inclined to be retained in the material upon reduction. The transport of ionic charge to compensate for the change

in the oxidation state of the polymer is then carried out mainly by means of ions in the electrolyte in which the redox process is carried out. The anions with low mobility can be distinguished by their ionic transfer numbers. The ionic transfer number is defined as the fraction of the ionic current carried by the particular anion taken as an average over essentially the full reduction of the material. The polymer is formed in the oxidized state (black) which is electronically conductive and can be reduced to the neutral state (yellow) which is insulating. For practical purposes, however, the reduction of thick (500µm or more) films will not proceed until it is complete even at very negative potentials. The material remains black in appearance and retains a certain electronic conductivity, although its resistance may increase with a reduction above approx. 90%. The anions with low mobility used in the materials according to the invention will generally be characterized by an average ionic transfer number of less than 0.1, preferably less than 0.05, for the anions with low mobility during reduction. A most preferred low mobility anion is an anion characterized by an average ionic transfer number of less than 0.01 for the low mobility anions during reduction;

These transmission numbers can be determined by elemental analysis of the polymers before and after reduction. The transfer number

(tA) for the anion with low mobility can thus be defined

as follows:

in which (NA)q is the number of molecules of the charge-compensating anion originally present in the polymer (when present in the oxidized state), and ^N. is the change in the number of molecules of the anion after essentially complete reduction (towards the neutral state).

The porous materials according to the invention are also distinctive in that they have an apparent density of from 0.01 g/cm 3 and up to the room density of the polypyrrole or the copolymer of pyrrole.

The bulk density or theoretical density of polymers is the density of the continuous, pure polymer without voids, pores, voids or inclusions. The bulk density or the theoretical density can usually be determined using flotation methods. The apparent density for less dense forms of the polymer, such as the porous materials, is defined from the polymer mass and the volume calculated from the material's external dimensions. As cavities and voids etc. are included in materials of the porous type, their apparent density will be lower than the room density.

The porous material according to the invention is also distinctive in that it has an electrochemically accessible surface area that is at least twice the surface area of a smooth film with the room density of the polymer or copolymer. Preferred materials have significantly larger surface areas (eg, 1000 times or higher than the surface area of smooth space density film).

The electronically conductive materials according to the invention comprise either polypyrrole or -pyrroles or, a copolymer or copolymers of pyrrole which can be obtained by (a) polymerizing mixtures of a pyrrole with other copolymers-

monomers only or by (b) grafting a comonomer or comonomers onto a polypyrrole polymer or by (c) grafting a pyrrole monomer or pyrrole monomers onto a preformed polymer based on a monomer other than pyrrole.

The pyrrole monomers that can be electropolymerized can be pyrrole or substituted pyrroles, such as e.g. the N-substituted or C-substituted pyrroles which are described in more detail below. Homopolymers of these pyrroles, and preferably the monopolymers of unsubstituted pyrrole, are included.

Copolymers of a pyrrole can be prepared, for example, by

to polymerize a mixture of pyrrole and one or more substituted pyrroles which may be substituted on the nitrogen atom or on one or more of the ring carbon atoms in the 3-position. The substituent is preferably a lower alkyl group with 1-7 carbon atoms, and it is more preferably a methyl group. Thus, e.g. copolymers of pyrrole and N-methylpyrrole or 3,4-dimethylpyrrole are produced by the method according to the invention. Alternatively, pyrrole can be copolymerized with other heterocyclic ring compounds, including those containing nitrogen (eg pyridine, aniline or indole etc.), furan or thiophene or with other aromatic or substituted aromatic compounds. The anions with low mobility incorporated in the materials according to the invention can be organic or inorganic anions. Examples of inorganic anions with low mobility that can be used according to the present invention include transition metal complexes, such as ferricyanide, nitroprusside, iron/sulfur agglomerate compounds, such as the redox centers of the rubredoxins and ferredoxins, boron agglomerate compounds, cobalt hexacyanide, other transition metal cyanide complexes, nitroprusside complexes or other transition metaloxy complexes or sulfides or chalcogenide complexes, e.g. W04~, Mo04~, Mo(CN)g~, Fe4S4C4H12~, Cr<0>4~ etc.

The anions with low mobility incorporated in the materials according to the invention are preferably organic anions. Examples of organic anions include those derived from organic sulfates or sulfonates, and these can be alkyl, cycloalkyl, aryl, arylalkyl or alkaryl sulfates or sulfonates. The anions that can be used in the present materials can contain more than one anionic active center, i.e. more than one ionizable group per molecule, e.g. more than one sulfonic acid group per molecule. The sulfonates and sulfates that can be used as the anions with low mobility in the materials according to the invention can be represented using the following formulas:

In the above formulas, R<1> denotes aliphatic

or an aliphatically substituted cycloaliphatic hydrocarbon or an essentially hydrocarbon group which is generally free of unsaturation and usually contains up to 30 carbon atoms although it may be polymeric and contain more than 30 carbon atoms. When R"*" is an aliphatic group, it will normally contain at least 4 carbon atoms, and when R<1> is an alkyl-substituted cycloaliphatic group, the alkyl substituents preferably contain 1-4 carbon atoms. Specific examples of R"<*>" include butyl, hexyl, octyl, lauryl, cetyl, octadecyl or groups derived from petroleum, saturated and unsaturated paraffin waxes or olefin polymers including polymerized monoolefins or diolefins containing 2-8 carbon atoms per olefinic monomer unit. R may also contain other substituents, such as phenyl-, cycloalkyl, hydroxy-, meraapto-, halogen-, nitro-, amino-, lower alkoxy-, lower alkylmercapto-, carblakoxy-, oxo- or thio groups or terminating groups, such as -NH -, -O-, -S-, but its overall hydrocarbon character is preferably retained.

R 2 is generally a hydrocarbon or substantially so

a hydrocarbon group containing 1-30 carbon atoms, although it may be polymeric and contain more than 30 carbon atoms. R<2>

is preferably an aliphatic hydrocarbon group, such as an alkyl, alkenyl or alkylaryl group. R 2 may also o contain substituents as listed above, including the above-mentioned interrupting groups, provided that its essentially hydrocarbon character is retained.

The group T in the above formulas V and VI is a cyclic nucleus which may be derived from an aromatic hydrocarbon, such as benzene, or from a heterocyclic compound,

such as pyridine. T is usually an aromatic hydrocarbon nucleus, especially benzene. The indices x denote the average number of ionized groups per molecule. The anion may contain additional sulfate or sulfonate groups that are not ionized, but connected to certain cation-active moieties. In formulas I-VI, x can have a value of up to 1000 or more when R or R 2 is a polymer group, but it is preferably 1-10, more preferably 1-6, and generally 1. The index y in formulas V and VI is a number from 1 to 5 and is preferably 1.

Anionic compounds that contain the anions that

are represented by the formulas I-VI, are commercially available or they can be easily prepared using well-known methods. Examples are salts with alkali or alkaline earth metals or ammonium salts.

Examples of sulfonates that can be used in the materials according to the invention include the anions of the following acids: hexylsulfonic acid, octylsulfonic acid, dodecylsulfonic acid, octyldecylsulfonic acid, laurylsulfonic acid, mahoganysulfonic acid, paraffin wax sulfonic acid, benzenesulfonic acid, naphthalene sulfonic acid, laurylcyclohexylsulfonic acid, dodecylbenzenesulfonic acid, polyethylene sulfonic acid with different molecular weight or polystyrene sulfonic acids with different molecular weight, etc. Styrene/maleic anhydride copolymers with sulfonate groups on the rings or styrene/maleic anhydride copolymers that have been partially or completely converted into the corresponding imide sulfonates are also usable anion-active components for the materials according to the invention. Such materials are derived from styrene/maleic anhydride copolymers which typically have an intrinsic viscosity of 0.06-1, preferably 0.06-0.3, dl/g, measured at 30°C in acetone, 0.4-1.0 g/dl.

A preferred embodiment of the materials according to the invention includes anions which arise from aliphatic compounds containing two sulfonic acid groups and can be represented by the formula wherein n is an integer from 2 to 20 or more, preferably from 2 to 12. These disulfonic acid salts can be prepared by using well-known methods, such as by reaction of alkyl dihalides with sodium sulphite. Particular examples of such compounds include the salts of ethanedisulfonic acid, 1,4-butanedisulfonic acid, 1,5-pentanedisulfonic acid, 1,6-hexanedisulfonic acid, 1,8-octanedisulfonic acid or 1,10-decanedisulfonic acid.

Examples of sulfates that can be used in the materials according to the invention include alkyl sulfates, such as lauryl sulfate, or polyethylene sulfates with different molecular weights.

Another group of sulfates that can be used as the anions with low mobility in the materials according to the invention,

are polysulfated polyhydroxy compounds. Such compounds can be prepared by reacting polyhydroxy compounds with a suitable reactant, such as chlorosulfonic acid, thereby converting one or more of the hydroxy groups into sulfate groups. Examples of polyhydroxy compounds that can be used to prepare such polysulfates include pentaerythritol; mannitol, tri-methylolpropane or dipentaerythritol etc. As mentioned, one or more of the hydroxy groups in these polyhydroxy compounds can be sulfated to produce a variety of products. Ammonium sulfates can be prepared directly from the polyhydroxy compounds by reaction with an aminosulfonic acid in the presence of a diluent, such as dimethylformamide.

Amide and preferably acrylamidealkanesulphonic acid anions can be used in the materials according to the invention. Particular examples of such anions include 2,2-bisacrylamide-1,1-dimethylethanesulfonic acid anion, 2-acrylamide-2-methylpropanesulfonic acid anion or poly(2-acrylamide-2-methylpropane)sulfonic acid in the form of the sodium salt of different molecular weight.

The anions with low mobility present in the materials according to the invention can also be formed from pentavalent phosphorus compounds. Examples of such phosphorus compounds are phosphates, phosphonates or phosphinates. The phosphorus compounds that can be used as the anions with low mobility in the materials according to the invention can be represented using the following formulas:

3 11

In the above formulas, R is equal to R or R yT as defined above, or it may be hydrogen, an alkali metal (e.g. lithium, sodium or potassium etc.) or an alkaline earth metal (e.g. calcium or magnesium etc.) .

R 4 is R 2 or R 2yT as defined above, or it may be hydrogen, an alkali metal (eg lithium, sodium or potassium etc.) or an alkaline earth metal (eg calcium

12 3 3

or magnesium etc.). Each of X , X , X and X is oxygen or sulfur, and each a and b is 0 or 1. The index z represents the average number of ionized groups per molecule. In the formulas XI-XIV, z can have a value of up to 1000 or more when R 1 or R 2 is a polymer, but it is preferably 1-10 and more preferably 1-4, and generally 1. It will thus be understood that the pentavalent phosphorus compounds may be, for example, organophosphorus, phosphonic or phosphine compounds including the acids, alkali metal salts or alkaline earth metal salts thereof, or a thio analogue of any of these.

Although usable electronically conductive materials can be produced by the method according to the invention and so that they comprise a polypyrrole or a copolymer of a pyrrole and an anion with low mobility as described above, the properties of the materials can be improved by the introduction of other components that provide certain desired properties. The electrolysis baths that can be used in the production of the materials according to the invention will preferably contain a plasticizer. Plasticizers are compounds which are well known in the relevant art and are able, when incorporated into polymeric compounds, such as polypyrrole or copolymers of a pyrrole, to increase the tensile elongation and/or decrease the polymer's modulus and/or increase the flexibility. The latter criterion has been used to define the term plasticizer as used in connection with the materials according to the present invention. Compounds that can increase the flexibility of the materials present are generally included in the electrolysis baths. In some cases, the anions with low mobility that are incorporated into the materials according to the invention have more than one function and can, for example, include the function of a plasticizer and/or a surfactant in the material according to the invention. For example, a number of the high molecular weight sulfates' or sulfonates listed above as low mobility anions can also act as softeners,

and they can also change the wetting properties of the polymer. A particular example is sodium lauryl sulfate which acts as

a low mobility anion and as a plasticizer for polypyrrole or copolymers of pyrrole.

The softeners which can be used for the materials according to the present invention include organic sulphates or sulphonates, such as alkyl, aryl, arylalkyl, alkaryl or polyolefin sulphates or sulphonates of the above types as anions with low mobility. Another group of compounds which can be used as softeners for the materials according to the present invention are polyhydroxy compounds.

The polyhydroxy compounds are preferably those which contain 2-6 alcoholic radicals, of which at least 1 is unsubstituted. The unsubstituted polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, .1,3-propylene glycol, glycerol, erythritol, pentaerythritol, arabitol/adonitol, xylitol, mannitol, sorbitol or neopentyl glycol. Polyhydric alcohols with a higher molecular weight can also be used. Examples of such alcohols include various polyethylene glycols and polypropylene glycol.

Partially acylated polyhydric alcohols can likewise be used for the materials according to the invention. The partially acylated polyhydric alcohols are preferably those containing 2-6 alcoholic radicals of which at least 1, but not all, are acylated with an aliphatic carboxylic acid with 8-30 carbon atoms. Examples are glycerol monooleate, glycerol distearate, sorbitan monostearate, sorbitan didecanoate, sorbitan tristearate, sorbitan dibehenate, erythritol monooleate , 1,1,1-trimethylol-propane monomyristate, pentaerythritol di-linoleate, ribitol mono-(9,10-dichlorostearate) or sorbitan monooleate etc.

The polyhydric alcohols can also contain ether bonds in their molecular structure. The ether-containing polyhydric alcohols can be obtained by dehydrating a polyhydric alcohol. Examples of such derivatives are sorbitan and mannitan. The ether-containing polyhydric alcohols can be obtained by reacting a polyhydric alcohol with an epoxide. The epoxides are for the most part hydrocarbon epoxides and essentially hydrocarbon epoxides. The hydrocarbon epoxide can be an alkylene oxide or an arylalkylene oxide. The arylalkylene oxides can be exemplified by styrene oxide, p-ethylstyrene oxide or p-chlorostyrene oxide. The alkylene oxides mainly include • the lower alkylene oxides, such as ethylene oxide, propylene oxide, 1,2-butene oxide or 1,2-hexene oxide. The essentially hydrocarbon epoxides may contain polar substituents. The polar substituent is usually a halogen radical, such as chlorine, fluorine, bromine or iodine, an ether radical, such as methoxy or phenoxy, or an ester radical, such as carbomethoxy. Examples of such epoxides are epichlorohydrin and butyl-9-10-epoxystearate. The number of ether bonds in the product is determined by the added amount of epoxy. It is thus possible to react a polyhydric alcohol, such as sorbitol, with 1,2,3 or more equivalents of an epoxide, such as propylene oxide.

The polyhydric alcohols which can be used for the materials according to the invention can also be ether-containing, acylated, polyhydric alcohols. These can be produced using a number of different methods. A polyhydric alcohol can be dehydrated and then acylated or an alcohol radical can be acylated first followed by dehydration of other alcohol radicals. As mentioned earlier, the ether bond can also be introduced by reacting an epoxide with the polyhydric alcohol before or after acylation. Examples of ether-containing, acylated, polyhydric alcohols include polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan tri-stearate, polyoxyethylene glycerol distearate, polyoxypropylene sorbitan linoleate or polyoxypropylene pentaerythritol mono-oleate.

A particularly preferred example of a group of plasticizers which can be used for the materials according to the invention are polyalkylene polyols, polyethers and polyglycerols, especially polyalkylene glycols in which the monomer unit may contain 1-4 carbon atoms, preferably 2 carbon atoms. A particular example is polyethylene glycol. The molecular weight of the plasticizers can vary within a wide range depending on the material to be modified and the properties to be modified when the plasticizer is incorporated. Polyethylene glycols with a molecular weight of 300-5000000 are included in the electrolytic bath composition and are useful for modifying the properties of the materials according to the present invention.

It has also been shown that when the electropolymerization

of pyrrole or polymerizable mixtures of pyrrole is carried out using an aqueous medium or a multiphase system as described below, the presence of polyethylene glycol within a molecular weight range contributes to the resulting polymeric materials gaining mechanical strength and flexibility. Furthermore, when polyethylene glycol of different molecular weight is added to the electrolysis bath used according to the invention, the morphology of the obtained polymeric material can generally be modified by varying the molecular weight of the added glycol.

The amount of softening agent present in the electrolysis bath used according to the invention can vary within a wide range, especially if the anion with low mobility also acts as a softening agent. The electrolysis baths used according to the invention will, however, generally contain less than 75, preferably less than 25, weight%

of the softener based on the total weight of the bath composition.

The mixtures that can be used for the production of the materials according to the invention can also contain redox groups. Redox groups are chemical groups that are capable of being exposed to changes in oxidation state and can be oxidized or reduced on an electrode. In this context, the groups should generally be reduced before or during the reduction of the polymer beyond what is necessary to change the oxidation state of the polymer, and therefore store additional charge. The oxidation and reduction of these groups may or may not be reversible. The incorporation of redox groups with suitable redox potentials in the materials according to the invention generally leads to an increase in the charge capacity of the material. The charge capacity for a polymer material is the total charge that is consumed per unit of mass when the material is oxidized or reduced and is usually expressed in coulomb/g or ampere-hours/kg. Examples of redox materials that can be used include transition metal complexes, and more preferably anionic transition metal complexes. Examples of complexes include halide complexes, amine complexes in which the amine may have the formula -NR^R^R^, wherein each R^, R^ and R^ may independently be hydrogen or an alkyl or an aryl^ group, oxy complexes, which molybdates, tungstates or vanadates, cyanide complexes, such as hexacyanide complexes of transition metals, iron cyanides, cobalt cyanides or molybdenum cyanide complexes. Other redox materials that can be used include nitroprussides, polysulfides, transition metaloxy compounds, sulfur compounds or chalcogenides.

The redox materials can be incorporated in an ionized state

in the materials according to the invention in an amount of up to 70% by weight, based on the weight of the combined material. Preferably, the redox materials are incorporated in an anionic state up to the amount necessary to neutralize the charge on the polymer skeleton.

Surfactants, which can also be referred to as wetting agents or emulsifiers, can be incorporated into the materials according to the invention and the electrolysis baths used for the production of the materials according to the invention. The surfactant can be hydrophilic or hydrophobic. The surfactant is typically a hydrophilic surfactant and generally has an HLB (hydrophilic-lipophilic balance) in the range of 10-20.

The surface-active agent can be of the cation-active/anion-active, non-ionic or amphoteric type. A number of such surfactants of each type are known in the relevant art, see e.g. McCutcheon's "Detergents and Emulsifiers", 1978, North American Edition, published by McCutcheon's Division, MC Publishing Corporation, Glen Rock, New Jersey, USA., especially pages 17-33.

Anionic surfactants contain negatively charged polar groups, while cationic surfactants contain positively charged polar groups. Amphoteric surfactants contain both types of polar groups in the same molecule. A general overview of applicable surfactants can be found in the Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Volume

19, from p. 507 (1969, John Wiley and Son, New York) and in the above compilation published under the name McCutcheon<1>p. The anionic or nonionic surfactants are preferred. The low-mobility anion incorporated into the polymer can also act as a surface-active agent.

Among the usable surfactants of the anionic type are the well-known metal carboxylate soaps, organosulfates, sulfonates, sulfocarboxylic acids or salts thereof and phosphates. Useful cationic surfactants include nitrogen compounds, such as amine oxides and the well-known quaternary ammonium salts. Amphoteric surfactants include amino acid type materials and similar types. Various cationic, anionic and amphoteric dispersants are available from the industry. Among the non-ionic surface-active agents are those treated with alkylene oxide, such as ethylene oxide-treated phenols, alcohols, esters, amines or amides. Ethylene oxide/propylene block copolymers are also useful nonionic surfactants. Glycerol esters and sugar esters are also known as nonionic surfactants. A typical group of non-ionic surfactants that can be used in connection with the derivatives according to the present invention are the alkylene oxide-treated alkylphenols, such as e.g. ethyleneoxydalkylphenol condensates.

A specific example of these is Triton^X-100, which contains an average of 9-10 ethylene oxide units per molecule and has an HLB value of approx. 13.5 and a molecular weight of approx. 628. One

a number of other suitable non-ionic surfactants are known, see e.g. the above publication of McCutcheon's and also the treatise "Non-ionic Surfactants" edited by Martin J. Schick, M. Drekker Co., New York, 1967.

Additional information regarding anionic and cationic surfactants can also be found in the textbooks "Anionic Surfactants", Parts II and III, edited by W.M. Linfield, published by Marcel Dekker, Inc. New York, 1976, and "Cationic Surfactants", edited by E. Jungermann, Marcel Dekker, Inc. New York, 1976.

The electronically conductive polypyrrole or copolymers of pyrrole according to the invention are produced by electropolymerization of a pyrrole or a copolymerizable mixture containing a pyrrole on an electronically conductive surface in an electrolytic bath. This contains a pyrrole or mixture of pyrrole and copolymerizable monomer, at least one electrolyte salt that includes an anion that will be incorporated into the polymer during its formation, and at least one liquid in which the pyrrole (and/or copolymer) and the electrolyte salt both:: have a final solubility. The bath may also contain another immiscible liquid or a gas or finely divided solid particles or combinations thereof. According to one embodiment, the electrolysis boat comprises a pyrrole or a copolymerizable mixture of pyrrole and water. According to another embodiment, the electrolysis boat comprises pyrrole or a copolymerizable mixture of pyrrole and an organic diluent,

According to a further embodiment, the electrolysis boat comprises pyrrole or the copolymerizable mixture containing pyrrole, water and an immiscible liquid, such as, for example,

an organic diluent. The latter embodiment, where the bath contains water and an immiscible, organic diluent and which is hereinafter referred to as the two-phase system, is favorable for the production of materials according to the invention which can be characterized by being porous and having very high surface areas.

The electropolymerization of a pyrrole or a copolymerizable mixture containing a pyrrole using a two-phase system, such as water and an organic diluent, comprises the steps that

A. an electronically conductive surface is immersed in an electrolytic bath containing at least one liquid and at least one immiscible liquid in which the pyrrole or the copolymerizable mixture is one of the liquids or is dissolved in at least one of the liquids, and

B. an electric current is passed through the bath at a voltage sufficient to electropolymerize the pyrrole or the copolymerizable mixture containing a pyrrole,

on the electronically conductive surface. Preferably, one of the liquids is water, and the immiscible liquid is an organic diluent. Examples of organic diluents that can be used for the preparation of the present materials include organic hydrocarbons, such as aliphatic or aromatic hydrocarbons or halogenated aliphatic or aromatic compounds, etc. Specific examples include white spirit, hexane, heptane, toluene, xylene, 1,2-dichloroethane , dichloromethane, carbonate tetrachloride or chlorobenzene.

The amount of the pyrrole or the copolymerizable mixture containing pyrrole in the electrolytic bath may vary within a wide range although the total amount must exceed the amount necessary to form the total desired amount of polymer. The amount of pyrrole dissolved in the electrolyte solution component or components of the electrolysis bath must be sufficient to provide a

reasonable reaction speed. This amount will usually

-3

vary from 10 molar up to saturation for the electrolyte or electrolytes. The amount of electrolyte salt in the electrolytic bath must be sufficient both to conduct the desired electrical current and to provide sufficient anionic materials to be incorporated into the polymer for the purpose of effecting charge neutralization. Typical concentrates--2

tions are from 10 molar and up to saturation of the bath, and

-2

more typically from 5 x 10 molar up to 1 molar in at least one phase.

As mentioned above, the electrolysis boat according to the invention can contain other components which make the materials according to the invention acquire desired properties. The bath can thus contain anions with low mobility, softeners, redox couples or surfactants etc. as defined above. When an aqueous system or a multiphase system containing water is used for the electrolysis boat, an emulsifier or an emulsion stabilizer can be incorporated to stabilize this system.

The emulsifier may be an aliphatic glycol or a monoaryl ether of an aliphatic glycol. The aliphatic glycol may be a polyalkylene glycol. It is preferably a glycol in which the alkylene radical is a lower alkylene radical with 1-10 carbon atoms. The aliphatic glycol can thus be represented by ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, tetramethylene glycol or hexamethylene glycol, etc. Particular examples of the ethers include monophenyl ethers of ethylene glycol, monoethylphenyl ethers of triethylene glycol, mono-a-octyl -3~naphthyl ether of tetrapropylene glycol, mono-polyisobutene (molecular weight 1000)-substituted phenyl ether of octapropylene glycol or mono-o,p-dibutyl phenyl ether of polybutylene glycol, monoheptyl phenyl ether of trimethylene glycol or mono-3,5-dioctyl phenyl ether of tetratrimethylene glycol etc. The monoaryl ethers are obtained by condensation of a phenolic compound, such as an alkylated phenol or naphthol, with one or more molecules of an epoxide, methylene oxide, propylene oxide, trimethylene oxide or 2,3-hexylene oxide. The condensation is promoted by a basic catalyst, such as an alkali or alkaline earth metal hydroxide, alcoholate or phenate. The temperature at which the condensation is carried out can be varied within wide areas, e.g. from room temperature to 250°C. It is usually preferably 50-150°C. More than one molecule of the epoxy can be condensed with the phenolic compound so that the product in its molecular structure can contain one or more of the radicals that emerge from the epoxy. A polar substituted alkylene oxide, such as epichlorohydrin or epibromohydrin, is likewise useful for the preparation of the mono-aryl ether product. and such a product is likewise applicable as an emulsifier.

Likewise, the mono- or dialkyl ethers of the aliphatic glycols are suitable as emulsifiers, in which the alkyl radical preferably has 2-20 carbon atoms (eg octyl, nonyl, dodecyl or behenyl etc). The fatty acid esters of the monoaryl or monoalkyl ethers of aliphatic glycols are also useful. The acids include e.g. acetic acid, formic acid, butanoic acid, hexanoic acid, oleic acid, stearic acid, behenic acid, decanoic acid, isostearic acid, linolenic acid and also commercially available acid mixtures, such as those obtained by hydrolysis of tall oils or spermaceti oils etc. Special examples are the oleate of monoheptylphenyl ether of tetraethylene glycol and the acetate of monopolypropylene (with molecular weight 1000)-substituted phenyl ether of tripropylene glycol.

The alkali metal and ammonium salts of sulfonic acids are likewise emulsion stabilizers. The acids can be represented by decylbenzenesulfonic acid, didodecylbenzenesulfonic acid, mahoganysulfonic acid, heptylbenzenesulfonic acid, polyisobutenesulfonic acid (molecular weight 750), decylnaphthalenesulfonic acid or tridecylbenzenesulfonic acid. The salts can be represented by the sodium, potassium or ammonium salts of the above-mentioned acids.

Emulsifiers include phosphatides, particularly those having the structural formula wherein G is from the group consisting of fatty acyl radicals and phosphorus-containing radicals having the structural group

wherein R' denotes a lower alkylene radical with 1-10 carbon atoms and R" and R"' lower alkyl radicals with 1-4 carbon atoms/and wherein at least one, but not more than two, of the radicals G are the aforementioned phosphorus-containing radicals. The fatty acyl radicals are for the most part those that are formed from fatty acids with 8-30 carbon atoms in the fatty radicals, such as octanoic acid, stearic acid, oleic acid, palmitic acid, behenic acid, myristic acid or oleostearic acid. Particularly desirable radicals are those that arise from commercially available fatty compounds,

such as soybean oil, cottonseed oil or castor seed oil. A particularly effective phosphatide is soybean lecithin which is described in detail in the Encyclopedia of Chemical Technology, Kirk and Othmer, volume 8, pp. 309-326 (1952).

The neutral alkali metal salts of fatty acids with at least 12 aliphatic carbon atoms in the fatty radical are also usable as supplementary emulsion stabilizers. These fatty acids mainly include lauric acid, stearic acid, oleic acid, myristic acid, palmitic acid, linoleic acid, linolenic acid, behenic acid or a mixture of such acids, such as those obtained from the hydrolysis of tall oil, spermaceti oil or other commercially available fats.

Only a small amount of the stabilizer is required for the purpose. It can be as small as 0.01 part and rarely exceeds 2 parts per 100 parts by weight of the electrolysis boat, In most cases it lies within the range from 0.1 to 3 parts per 100 parts of the bathroom.

As mentioned above, the electropolymerization process carried out according to the invention can be carried out in an organic diluent, and more particularly in an organic phase containing less than 3% and more preferably less than 1% water. Examples of organic diluents include polyols, organic carbonates, ethers or nitriles, etc. It is of significant importance that the solvent is not exposed to competitive oxidation during the electropolymerization and thus adversely affects the polymerization or significantly reduces the current yield during the polymerization process.

According to a preferred embodiment of the invention, however, the electropolymerization of pyrroles is carried out from aqueous media, either as a single-phase aqueous system or a multi-phase aqueous system. A number of the advantages of using aqueous systems will be clear, including reduced costs, good availability of and easy purification of water, the possibility of using a wide range of ionic materials such as electrolyte salts in water and the possibility of using high concentrations of ionic materials and thus enable the use of high electrochemical currents and high polymerization formation rates. Under controlled conditions, intact homogeneous films of poly-pyrroles can be formed on a variety of substrates in aqueous media. The thicknesses vary from less than 100 Å to a few millimeters for denser materials. In some cases, the current density exerts an effect on the morphology. The morphology of the electropolymerized materials according to the invention can be further modified by using the already mentioned additives.

It has been observed that improved results are obtained when the electroplating bath is carefully agitated during the electropolymerization of the monomers. Agitation can be achieved by any known method, including vigorous stirring with paddle wheels, magnetic stirrers, ultrasonic agitation, vibration, or by bubbling gases through the bath to achieve sufficient agitation (including gases formed on the counter electrode). Electropolymerization is achieved by passing an electric current through the bath with a voltage sufficient to electropolymerize the pyrrole or the copolymerizable mixture containing a pyrrole on an electronically conductive surface immersed in the electrolysis bath. The electric current can be a continuous electric current or a varying electric current, such as a pulsating current. The electric current is generally direct current, although alternating current can be used in some cases.

The voltage on the anode must be sufficient to oxidize the monomer without it causing significant changes in the bath, such as the breakdown of a bath component, which could adversely affect the polymerization. In general, current densities of up to 2 A/cm 2 can be used, but preferably current densities that do not exceed 500 m A/cm 2 are used. According to more preferred embodiments, the current density will be below 250, and more generally below 100, m A/cm<2 >

At the above-mentioned current densities, pyrrole becomes or

the copolymerizable mixture of a pyrrole electropolymerized on the electronically conductive surface. Depending on the particular constituents of the plating bath, the electro-<p>polymerisable polypyrrole can be formed in the form of a powder on the electronically conductive surface and fall into and disperse in the electrolysis bath or it can be deposited on the conductive surface. The deposit can be in the form of a film that is smooth and dense or uneven with a density that is lower than the room densities or the theoretical density. The room density or theoretical density of polymers is the density of the continuous, pure polymer that does not contain voids, pores, depressions or inclusions. The room density or the theoretical density can usually be determined using flotation methods. Examples of non-uniform deposits include porous films, powders or dendrite-shaped materials, etc. The nature of the cation or cations as well as the species

of the anion or anions present in the electrolysis bath affects the electropolymerization. The morphology of the deposit on the electronically conductive surface can be regulated and changed by incorporating different complexing agents for the ionic components in the electrolyte in the electrolysis bath. Examples of materials that act as growth regulators when incorporated into the electrolysis boat include the above-mentioned nonionic softeners (eg, polyalkylene glycol, such as polyethylene glycol), cryptands, or commercially available crown ethers, such as 12-Crown -4, 15-Crown-5 or 18-Crown-6 marketed by Aldrich Chemical Co.

The temperature of the electrolysis bath during the electropolymerization process is generally kept between 15 and 50°C, although polymerization proceeds within a much wider temperature range. The reaction is carried out at or approximately at room temperature and preferably under thermostatically controlled conditions.

A number of electronically conductive substrates which are not exposed to competitive oxidation during the electropolymerisation can be used in carrying out the present method. Not all types of metal can be used for the overall range of bathroom recipes. For example, although steel surfaces are useful for electropolymerizing pyrrole in the presence of sodium lauryl sulfate and water, the electrolysis bath containing pentaerythritol tetrasulfate and water will not lead to a satisfactory film being deposited on the steel, but to a satisfactory coating being deposited on nickel substrates. . The choice of the particular substrate material can be easily determined by the person skilled in the art with a minimum of experimentation. The size and shape of the substrate used in the execution of the present method will vary depending on the type of cell in which the electropolymerization process is carried out and on the desired shape of the polymer.

When e.g. flat films are desired, the substrate will have the form of a flat plate in a parallel plate cell.

According to a preferred embodiment of the present method, a rotating cylindrical anode or a movable belt anode is used from which the polymer is removed by a continuous process. The polymer can also be collected or removed from a stationary electrode in a continuous manner.

The time required to produce a certain amount or thickness of polymer will depend on several variables, including current density, bath temperature,

the size or physical dimensions of the electronically conductive surface and the temperature of the electrolytic bath. In addition, the desired special type of morphology will be an important consideration when it comes to choosing the values for the process variables, such as temperature, current density, coating time or voltage etc.

One of the advantages of the present method, especially in connection with aqueous systems, is the possibility of producing films with regulated thickness within a wide thickness range, and especially films with a thickness above 250 µm, and especially films with a thickness of from 0.5 mm to 2 cm. A number of known methods have not been developed to the required perfection, so they will not be able to produce anything but thin films (200 µm or less).

In the general method according to the invention, the electronically conductive surfaces are introduced into the electrolysis bath and connected to a power source. The polymer is formed at the anode. The counter electrode can consist of the bath tank or - a separate conductive surface or surfaces can be introduced into the electrolysis bath. The bath may have a separate compartment for the secondary electrode, but a design with one compartment is preferred.

When the electropolymerization process is finished, the substrate is removed from the electrolysis bath, and the electropolymerized material is mechanically removed from the surface. This polymer can be washed with water and with various non-aqueous solvents, (e.g. ethers or liquid hydrocarbons etc.) to remove any unwanted deposits on or in the material. If the deposited material has not been completely dried, this can, if desired, be carried out by heating the polymer to an elevated temperature, preferably under vacuum. The particular temperatures will depend on the nature of the pyrrole or the copolymerizable mixture of pyrroles used in carrying out the process, but they will generally be below 250> preferably below 100°C.

As mentioned earlier, the morphology and physical nature of the materials that have been electropolymerized using the present process will depend on a number of variables, including the nature of the substrate, the solvent, the temperature, the agitation, the current density or the electrical voltage, etc. Continuous films with a density that is approximately equal to the bulk density of the polymer can be produced using the present method when organic or aqueous one-phase systems are used. If it is desired to produce more uneven films which are characterized by low density and large surface area, the multi-phase processes described above, especially the aqueous two-phase systems, are advantageous. According to one of the preferred embodiments, the anions with low mobility are introduced into the materials produced by the present method by including the anions in the electrolytic bath. When the anions have been incorporated into the polymer materials according to the invention, the anions, as mentioned, have low mobilities and are essentially held permanently in place in the polymer during reduction and during any subsequent oxidations or reductions.

One of the unexpected advantages of the preparation according to the invention of pyrrole polymers and copolymers containing the low mobility anions is the fact that the polymer can be discharged and charged during at least hundreds of cycles,

see e.g. example 21. This is surprising as it was to be expected that highly mobile anions would give the greatest reversibility. The mechanism for the observed reversibility is not known, but it is believed to involve forced transport of another ion or ions. Such materials are therefore classified as electrochemically reversible poly-

more and can therefore be used in the production of charging

batteries only.

The method according to the invention is described in more detail using the following examples. Unless otherwise stated, all parts and percentages are based on weight.

In addition, unless otherwise stated, in the examples below, electropolymerizations are carried out at 2A for 30 minutes using a Hanovia type arc lamp power supply controlled by a Variac. The agitation is carried out with a horizontal, perforated glass disk which is mounted on the bottom of a stirring bar (1-2 cm from the bottom of the bath) and which is quickly vibrated up and down with a device of the "Vibro-Mixer" type. The temperature is regulated with an ice bath. Both electrodes consist of steel plates with dimensions 15 x 7.5 x 0.05 cm (AISI no. 10/10) arranged parallel to each other and degreased with toluene. The surface area (on one side)

of each electrode immersed in the bath is 70 cm 2 and the distance between the electrodes is 5.5 cm. The polyethylene glycol used in some of the examples has an average molecular weight of 15-20,000. The bathroom is exposed to the atmosphere. The descriptions of the polymer films according to the examples below do not cover edge effects. These effects produce irregularities that rarely affect more than 5% of the film's total mass.

Example 1

The following components are used:

The above-mentioned first four components are mixed in a container until the mixture has become homogeneous, and 3.75 ml of the mixture is introduced into a 10.8 x 8.9 x 5.7 cm reaction container. Two steel plate electrodes are brought into place. Heptane

(50 ml) is added, and the agitation is carried out mechanically with an apparatus of the "Vibro-Mixer" type.

Four films are being produced separately at 2A during

a reaction time of 30 minutes. The temperature is regulated with an ice bath and is initially 21°C and increases to 34-37°C during the reaction. The current is kept at 2A, but the voltage changes from approx. 60 V to approx. 40 V during the reaction. The electrolyte side of each film has a few irregularities in the form of dendritic shaped protrusions (about 1 mm), and these protrusions are removed by light grinding before the films are removed from the electrode surfaces. Each film is carefully rinsed with distilled water and with heptane.

Two of the films are completely dried in a vacuum oven in

24 hours at 50°C. The cleaned films obtained in this way appear to comprise 3 layers. The first layer, which is the layer closest to the steel plate, is smooth and continuous. The second layer, which is close to the smooth layer, is a uniformly porous material, while the third layer, which is close to the second layer, is denser and less porous than the second layer. From the other two films prepared according to this example, the back layer or smooth layer is removed and divided into 1.9 cm strips. The strips are cleaned in a "Soxhlet" type extractor for 15 hours with distilled water. After drying at room temperature, the pieces are further dried in a vacuum oven for 24 hours at 50°C.

Example 2

A mixture of 5 g of pyrrole, 1 g of sodium ethanedisulfonate,

2 g of polyethylene glycol and 200 g of water are prepared and introduced into an 8 x 7 x 4.5 cm reaction vessel. The cathode is a 15 x 5 x 0.025 cm piece of "Precision brand" spacer steel (a product commercially identified as NIDA/SIDA 1613D Al). The anode is a 10 x 5 x 0.05 cm plate of "Nikkel 200" which is nickel of high purity. The surface area (one side) of each electrode immersed in the bath is approx. 40 cm. Toluene (20 ml) is added and the mixture is agitated using a Vibro-Mixer. The electropolymerization reaction is carried out for 15 minutes at a constant current of 0.5 A and a voltage of approx. 17 V. The film that forms on the electrode is removed and turns out to be a relatively porous, even film with a thickness of 0.3-0.4 mm.

Example 3

A mixture of 20 g of pyrrole, 4 g of pentaerythrityl tetrahydrogensulphate, 4 g of polyethylene glycol and 800 g of water is prepared and mixed until it is homogeneous. 375 ml of the mixture is introduced into a 5.7 x 8.9 x 10.8 cm reaction vessel, and 50 ml of dichloromethane is also introduced into the vessel. For this example, a steel plate (AISI No. 10/10, 15 x 7.5 x 0.05 cm) is used as the cathode and a "Nickel 200" plate (14.2 x 7.6 x 0.025 cm) as the anode. The electropolymerization is carried out in the normal way during 15 minutes while a current of 2 A is maintained. A porous mass with a thickness of approx. 1 cm and low density (below 0.1 g/cm 3) are available. The porous mass is electronically conductive.

Example 4

A mixture of 20 g of pyrrole, 10 g of sodium 1,10-decanedi-sulfonate, 10 g of polyethylene glycol and 800 parts of water is prepared, and 375 ml is added to each of two reaction vessels. Heptane (50 ml) is added to each reaction vessel, and the electropolymerization is carried out in the normal way with a current of 2 A. The electropolymerization in the first reaction vessel ends after 5 minutes and gives a thin, black, electronically conductive film covered with small dendritic protrusions with a height of approx. 1 mm.

The electropolymerization reaction in the second container is carried out for 39 minutes and produces a thicker base film covered with small dendritic protrusions with approximately the same dimensions as for the previously mentioned film.

Example 5

A mixture of 10 g<p>yrrol, 10 g sodium lauryl sulfate

and 0.5 g of polyethylene glycol are prepared and introduced into the reaction vessel. For this example, both electrodes are

steel plates, and the agitation is carried out with a "Vibro-Mixer". The electropolymerization reaction is carried out for 20 minutes at a current of 2 A. A thick, relatively uniform coating is deposited on the anode, and the coating is covered with small dendritic out-, . stitches that can be easily removed by careful sanding.

Example 6

The procedure of Example 5 is repeated, except that 50 ml of heptane is added to the mixture in the reaction vessel, and the electropolymerization is carried out for 5 minutes at 2 A. The film produced in this way is more porous than the material obtained by the method of Example 5, and it is covered with dendritic projections.

Example 7

The ammonium salt of pentaerythritol tetrasulfate is prepared from pentaerythritol and sulfamic acid in N,N-dimethylformamide. A mixture of 5 g of pyrrole and 5 g of the ammonium salt in 200 ml of water is prepared and electropolymerized in an 8 x 7 x 4.5 cm reaction vessel in which the cathode is a 15 x 5 x 0.025 cm "Precision brand" steel plate and the anode a 6.4 x 5 x 0.026 cm nickel plate. About. 40 cm 2 of the nickel plate is immersed in the bath. The distance between the electrodes is 4.5 cm. Electropolymerisation is carried out at a current of 0.3 A for 10 minutes and produces a black, electronically conductive film which is characterized by a somewhat rough surface on the film's dissolution side.

Example 8

The procedure according to example 7 is repeated, except that 2 g of polyethylene glycol is incorporated into the mixture in the reaction vessel. The black, electronically conductive film produced in this way is smoother and smoother on the dissolution side than the film obtained according to example 7.

Example 9

The ammonium salt of mannitol hexasulfate is prepared from mannitol and sulfamic acid in dimethylformamide. A mixture of 5 g of pyrrole and 1 g of this ammonium salt is dissolved in 200 ml of water. The apparatus described according to example 7 is used, and the electropolymerization is carried out at a current of approx. 0.4 A

within 20 minutes. The product is a black, electronically conductive film that is shiny on the substrate side and rough on the solution side. *

Example 10

The procedure according to example 9 is repeated, except

that 2 g of polyethylene glycol is added to the mixture in the reaction vessel. According to this example, a smoother film is obtained which is far smoother on the resolution side.

Example 11

A mixture of 15 g of pyrrole in 500 g of water is prepared, and another mixture of 10 g of potassium ferricyanide and 5 g of polyethylene glycol is prepared in 400 ml of water. The two solutions are mixed together and shaken. About. 4 50 ml of the mixture is poured into the 10.8 x 8.9 x 5.7 cm reaction vessel. The electrodes used for this example are both steel plates. Electro-polymerization is carried out at 5 A. At the beginning of the reaction, the temperature is 23°C and the voltage is 22 V. During the electro-polymerization reaction, the temperature is stabilized at 31-32°C using an ice bath. At this temperature, 20 V is necessary to maintain a current of 5 A. The distance between the electrodes is 5.5 cm. The electropolymerization reaction is carried out for 40 minutes. The polymer is then removed from the anode. This film is 0.8 mm thick, black and electronically conductive. The film is smooth on both sides although it is smoother on the substrate side.

Example 12

The procedure according to example 11 is repeated, except that the polyethylene glycol with a molecular weight of 15,000-20,000 is replaced by an equal weight of Carbowax® 4000 (a polyethylene glycol with a molecular weight of 4,000). The electropolymerization reaction is carried out at 5 A, and approx. 20 V is required to maintain this amperage during the reaction period of 40 minutes. The bath temperature varies from 22°C to 32°C. The polymer is removed from the electrode, and the film thus obtained

is black and electronically conductive. The substrate side is smooth,

while the dissolution side is covered with dendritic projections.

Example 13

A mixture of 2 g of pyrrole, 0/4 g of a 50% aqueous solution of the sodium salt of 2-acrylamide-2-methylpropenesulfonic acid and 100 ml of water is prepared and mixed until it has become homogeneous. For this example, the cathode of the reaction vessel is a platinum strip (0.5 x 3 cm) and the anode a gold surface (2 x 4 cm) with approx. 4 cm o submerged in the bath. The electrodes are rinsed with distilled water before use. The electropolymerization according to this example is carried out using a Hewlett Packard model 6824A power supply/amplifier. Electropolymerization The ion polymerization is carried out at a current of 24 mA and a voltage of 15 V for 2 minutes. A thin, black, electronically conductive film is deposited on the gold surface.

Example 14

The procedure according to example 13 is repeated, except that the electrolyte salt used is the sodium salt of poly-2-acrylamide-2-methylpropenesulfonic acid with an inherent viscosity of 0.1 dl/g (measured in 0.5 N NaCl at 30°C). The electropolymerization is carried out at 30 mA and 20 V for 2 minutes. A smooth, thin, shiny, black, electronically conductive film is deposited on the gold-over lath.

Example 15

A mixture of 20 g of pyrrole, 20 g of sodium lauryl sulfate,

10 g of polyethylene glycol and 800 g of water are prepared, and 375 ml

i of this mixture is added to the 10.8 x 8.9 x 5.7 cm reaction vessel. Heptane (50 mL for each experiment) is then added to the reaction vessel and agitation is performed with a rapidly vibrating glass disc. The temperature is regulated with an ice bath. For this example, the electropolymerization is carried out

j at a current of 2 A. The reaction time is 30 minutes and the reaction temperature 20-38°C. The polymer formed on the anode is removed and purified by washing it several times with distilled water

water. The film produced in this way comprises a very thin base closest to the substrate, an even porous layer close to the base layer and a denser/wrinkled and less porous layer on the electro-listening side. The polymer layer is removed from the electrode and a 4 x 1 cm strip is cut from the film and its thin base is removed. The rest of the film is split into pieces and rinsed several times with distilled water together with the strip. The pieces and strip are then further rinsed in a "Soxhlet" type extractor using distilled water for 15 hours (about 40 extractions). The materials are then dried in a vacuum oven for 29 hours at 80°C. This polymer is electronically conductive and can be dry ground into a porous powder that can easily be cold pressed into various desired shapes without any additives. The shaped pieces obtained in this way are also electronically conductive.

Example 16

The procedure according to example 15 is repeated, except that the mixture only contains 7.5 g. polyethylene glycol. The electropolymerization of the mixture leads to a thinner, denser film than that obtained according to Example 15. The film also does not appear to be as flexible, and the corresponding powder does not allow cold pressing as well as the powder obtained according to Example 15.

Example 17

The procedure according to example 15 is repeated, except

from the fact that the mixture only contains 5 g of polyethylene glycol. The film obtained in this way is electronically conductive, thinner than the film obtained according to example 16 and less uniform.

Example 18

A mixture of 40 g of pyrrole, 40 g of sodium lauryl sulfate,

15 g of polyethylene glycol and 1600 g of water are agitated until it has become homogeneous, and 1200 ml is added to an 8.25 x 14 x 19 cm plastic reaction vessel. Both electrodes are 14 x 19 x 0.1 cm steel plates (AISI no. 10/10) degreased with toluene.

Heptane (150 ml) is added and the agitation is carried out with a "Vibro-Mixer". The surface area of the anode covered with polymer is approx. 250 cm 2. The electropolymerization reaction is carried out for 1 hour at a direct current strength of approx. 4 A. The product is removed from the anode and partially pulverized by hand while washing with distilled water. After further washing [Soxhlef extraction with distilled water) and drying (vacuum oven, 20 hours, 85°C), the polymer was further pulverized in a mortar. In this way, a finely divided, black, electronically conductive powder was obtained.

The powder obtained according to this example can be cold-pressed at room temperature in a dry state without any additives, and the pressed electrodes obtained in this way show improved electronic conductivity compared to the dried electropolymerized films. The density of the electropolymerized film is approx. 0.2 g/cm 3, while the density of the pressed electrode is approx. 0.8 g/cm3.

Example 19

The procedure according to example 18 is repeated, except that the power source is a simple full-wave rectifier (12 A standard current) which is controlled with a "Variac". The voltage requirements are essentially the same as according to example 18.

Example 20

An electrolysis bath is prepared containing 1 g of phenylphosphonic acid and 2 g of pyrrole in 100 g of water. The electropolymerization is carried out in the unstirred bath for deposition on a gold strip with the dimensions 3 cm x 0.5 cm. The gold strip is immersed to a depth of 1 cm. A platinum counter electrode is used, and a current of 1 mA is maintained for 300 seconds. The product is a black, electronically conductive film.

According to particularly advantageous embodiments, polymers or copolymers prepared by the present method can be heat treated to improve their electrochemical storage capacity. The heat treatment is preferably carried out at a temperature above the material's transition temperature as observed using differential scanning calorimetry (DSC) within the range of approx. 60 C. For example, a temperature within the range from 60°C up to the polymer's decomposition temperature, preferably from 80°C to 100°C, can be used. The heat treatment is preferably carried out under vacuum or a partial vacuum (e.g. an absolute pressure of about 1 mm Hg or less) and is continued until equilibrium has been achieved or substantially achieved (e.g. 10-20 hours ).

The electronically conductive polymers or copolymers produced according to the invention can be used, e.g. for electrodes in electrochemical cells (e.g. as electrodes in batteries, both primary and secondary batteries), as coatings for photo-cells to inhibit photocorrosion or corrosion processes, for catalytic electrodes, for electrical conductors, for conductive substrates and mixtures for composite electrodes , for switchgear or as permanent or corrosion-resistant electropolymerized coatings. The electronically conductive polymers produced according to the invention can also be used for applications in the solid state (e.g. to form compounds) and/or for photovoltaic devices or photoelectrochemical devices and as reversible electrode materials in electrochemical cells and batteries.

Electrodes produced according to the present invention can be positive or negative and, in addition to polymer, can contain a suitable binder and/or suitable carbon materials with a large surface area. They can also contain at least one other redox material.■ Suitable binders are inert polymeric binders which do not hinder the electrochemical performance of the resulting electrode. An example of such a binder is a halogenated polymeric material, such as polytetrafluoroethylene which is preferably introduced from an aqueous suspension, and such a suspension is commercially available, e.g. under the trade name Teflon^ T30B. Polytetrafluoroethylene introduced in the form of a powder can be used. Other<p>olymers, e.g. polypropylene, may be suitable for use in such materials under conditions that are not strongly oxidizing. Carbon grades with a large surface area which are suitable are such materials with a surface area of 1-2000, preferably 60-1200, m 2 /g. Examples of commercially available carbon

qualities with a large surface area and which can be used,

is "RB Carbon" which is stated to have a surface area of approx.

1200 m^/g, and "Shawinigan Black" which is stated to have a surface area of 60-65 m 2 /g.

Polymeric electrodes can be produced according to the invention by mixing a polymer according to the invention with optional components consisting of a binder, a carbon quality with a large surface area and/or other redox materials with water or an organic liquid (e.g. white spirit) for to obtain a paste-like mixture. This is then cold pressed or rolled using standard methods, preferably at a pressure in the range 3 5-844

kg/cm 2 and a temperature within the range from room temperature to the decomposition temperature of the polymer, in order to obtain an electrode with the desired shape. The polymer is preferably heat-treated to increase the electrochemical storage capacity before or after it has been incorporated into the mixture.

The polymeric electrodes provided by the present invention: either in the form of anodic films or pressed from powder, are suitable for use in electrochemical cells, in particular electrochemical accumulator cells or batteries (both primary and secondary batteries) as the positive and/or the negative electrode. These electrodes can have any desired size and shape as these are dependent on the size and shape of the electrochemical cell or battery in which they are used.

In electrochemical cells in which the polymeric material produced according to the invention constitutes the positive electrode, a negative metal electrode can be used. The negative metal electrode is designed and constructed in accordance with standard practice and is preferably of an alkali metal or an alkaline earth metal or an alloy of any of these. Preferred alkali metals are lithium, sodium and potassium. Preferred alkaline earth metals are magnesium and calcium. Suitable alloying elements are e.g. aluminum and silicon,

In electrochemical cells in which the polymeric material produced according to the invention constitutes the negative electrode, the positive electrode may be made of any material (ie metallic or non-metallic), provided that the positive electrode is electrochemically more positive than the negative polymeric electrode produced according to the invention.

Both polymeric positive and negative electrodes can

according to the present invention is provided in an electrochemical cell. These electrodes may have different compositions or they may have the same composition and/or be made by the same method, provided that these electrodes can be brought to sufficiently different states of charge that an efficient electrochemical cell will be obtained. The polymeric electrodes (negative and positive) which can be provided according to

the present invention preferably comprises porous, electronically conductive materials comprising an electropolymerized polypyrrole or copolymer of a pyrrole with an apparent density of from 0.1 g/cm 3 up to the bulk density of the polypyrrole or copolymer and with a surface area that is at least twice the surface area for a smooth film with a bulk density corresponding to that of the material. These electrodes preferably contain one or more anions with low mobility which are characterized by having an average ion transfer number during reduction of less than 0.1, preferably less than 0.01. An advantage of the positive electrodes comprising the polymers obtained according to the present invention is that the electronic resistance of such electrodes increases as the cell's discharge voltage approaches 0 V, and they thus tend to protect the electrochemical cell against damage caused by overdischarge.

Of the drawings, Fig. 1 shows a flooded lithium cell

in laboratory scale with an outer large container 1 with a cap 2. The cap 2 has a hole in the middle into which a rubber stopper, 3 is inserted. A small container 4 is located inside the large container 1 and is held in place by a rubber flange 14.

The lithium cell's elements are kept in place in the small container 4. The larger container 1, the cap 2 and the cap 3 are used to be able to maintain a special atmosphere, such as argon. The desired atmosphere, such as argon is introduced through a plastic tube which is inserted through the cork and is indicated at 10, and the argon flows out through a tube 11.

A polymer strip 6 according to the invention is suspended in

the inner container 4 using nickel contacts 13,

and two lithium electrodes 5 and 9 are also suspended in the inner container 4 through the cap 3 using platinum hooks 8. The polymer electrode 6 is a positive electrode, while the lithium electrode 5 is a negative working electrode and the lithium electrode 9 a reference electrode. The working electrode 5 is larger than the reference electrode 9. Sufficient non-aqueous electrolyte 12 is introduced into the inner container 4 so that an electrolyte level 15 is obtained below the platinum hooks 8

level and so that part of the positive electrode 6 and the two lithium electrodes 5 and 9 are covered.

The reversible storage of charge in the materials produced according to the invention can also<p>be demonstrated in a flooded cell in a glove box filled with argon, as shown in

Fig. 2. A glass container 30 contains 50 ml of a non-aqueous electrolyte 31. A strip 32 of the polymer produced according to the invention is held suspended between strips 33 and 34 of active metallic lithium and is in electrochemical, ionic connection with strips 33 and 34 via the electrolyte 31. The lithium electrode 33 is a negative electrode and acts as a source (during discharge) and a well (during charge) for lithium ions. The lithium electrode 34 is arranged close to the strip 32 and serves as a reference electrode. No current flows through the electrode 34.

When active metals, such as lithium, sodium or calcium, are used as negative electrodes, non-aqueous electrolytes are used. These electrolytes are typically organic liquids with dissolved salts of the electroactive materials. For example, well-known electrolytes are used for cells with negative lithium electrodes, such as e.g. propylene carbonate/1.OM lithium perchlorate (PC/1.0 M LiCl0 4 ), tetrahydrofuran/1.5 M lithium hexafluoroarsenate, 2 Me tetrahydrofuran/1.0 M lithium hexafluoroarsenate or mixtures thereof, etc.

The invention also relates to the use of the electronically conductive polymer materials according to the invention in primary and secondary batteries, as shown in Figs. 3 and 4, which comprise a negative alkali metal electrode 45 (e.g. of lithium, sodium or potassium), a separator 46, a polymer positive electrode 47 manufactured according to the present invention, a feed-through insulator 49 of ceramic or glass, spacers 50 and 51 and a negative metallic electrode contact 52. A metallic case 48 is used to hold the cell components in place and to achieve electrical contact with the positive electrode 47. The negative electrode 45 is electronically isolated from the positive electrode contact 48 by means of the insulator 49. Alternatively, the container for the cell can be made of an insulating material, such as a plastic, and the electrical contact to the electrode can be achieved by means of metallic grids, sieves or foils etc. According to a preferred embodiment, a cylindrical enclosure is used f or the negative electrode 45, the separator 46 and the positive electrode 47 in a cell with a spirally wound design.

According to another embodiment of the present invention, the electronically conductive polymer material is used in an electrochemical energy storage cell 60, according to Fig. 5, with a layered structure and which includes a polymer positive electrode 61 which is produced according to the present invention. a negative lithium electrode 62, a lithium reference electrode 63, glass fiber separators 64, gold contacts 65/66 and 67, glass plates 68 and 69 and an epoxy seal 70. The cell is mounted in dry air or in an inert atmosphere, e.g. argon.

According to another preferred embodiment of the present application, this also applies to the application of

the electronically conductive polymer material in a layered or stacked cell 71, according to Fig. 6, in which a number of positive and negative electrodes are respectively parallel

connected to increase the maximum current that can be supplied by the battery pack obtained. The cell 71 includes parallel and spaced apart polymer electrodes 72a-d which are manufactured according to the present invention, and parallel and spaced negative electrodes 73a-d which are parallel to and spaced from the electrodes 72a-d. The electrodes 72 and 73 are located in a container 74. This is preferably electronically insulating. The electrode 73a is arranged parallel and at a distance between the electrodes 72a and 72b. The electrode 73b is arranged in parallel and at a distance between the electrodes 72b and 72c. The electrode 73c is arranged parallel to and at a distance between the electrodes 72c and 72d. The electrode 73d is arranged parallel to and at a distance below the electrode 72d. Electrodes 72a-d are in communication with a contact 76 projecting from the container 74. Similarly, electrodes 73a-d are in communication with a contact 77 projecting from the container 74. A separator material containing a suitable electrolyte,

is dispersed throughout the entire interior of the container 74. Although four electrodes 72a-d and four electrodes 73a-d are shown on

Fig. 6, it will be understood by the person skilled in the art that the number of such electrodes can be fewer or greater than four and that this number depends on the requirements placed on the cell 71.

According to a further embodiment of the present application of the electronically conductive polymer material according to the invention, this takes place in a layered or stacked cell 81, see Fig. 7, in which a number of stacks of alternating positive and negative electrodes provide a bipolar structure in order to increase the overall voltage of the obtained battery pack. The cell 81 includes polymer electrodes 82a-d arranged in parallel and at a distance from each other produced according to the present invention, and negative electrodes 83a-d arranged in parallel and at a distance from each other which are parallel to and located at a distance from the electrodes respectively. 82a-d. Separators 84a-d which can be made e.g.

of fiberglass and containing a suitable electrolyte, is arranged between the electrodes 82a-d and 83a-d as shown. The electrodes 82a-d and 83a-d and the separators 84a-d are located in an electronic

insulating container 85. This also contains bipolar, electronically conductive plates 86, 87 and 88 which divide the container 85 into four insulated compartments 90, 91, 92 and 93. The electrodes 82a and 83a and the separator 84a are placed in the compartment 90. The electrodes 82b and 83b and the separator 84b is placed in the compartment 91. The electrodes 82c and 83c<. and the separator 84c are placed in the compartment 92. The electrodes 82d and 83 and the separator 84d are placed in the compartment 93. Contact with the two ends of the series stack is obtained by means of contacts 95 and 96 which protrude from the container 85. Although four electrodes 82a- d and four electrodes 83a-d are shown in Fig. 7, it will be understood by the person skilled in the art that the number of such electrodes can be fewer or greater than four and that this number depends on the requirements placed on the cell 81.

Example 21

The material according to example 6 is used as a positive electrode material in lithium cells 60, the construction of which is shown in Fig. 5. The cell 60 is mounted in a dry argon atmosphere. The polymer material 61 is electropolymerized on a gold strip that serves as contact 65. The thickness of each separator 64 is approx. 0.5 mm. The separators 64 are impregnated with electrolyte consisting of 1 M LiClO^ in propylene carbonate. The negative electrode 62 and the reference electrode 63 are made of lithium. The cell 60 which is arranged in the form of a layer: between the glass plates 68 and 69, as shown, is clamped together and the edges sealed with the epoxy seal 70.

A thin polymer film is produced as described in example 6, except that it is electropolymerized during a shorter time. The film is examined as the positive electrode in the cell 60.

The areal density of the film is approx. 0.1 mg/cm 2. The discharge is carried out at a current of approx. 0.1 mA/cm 2 and ends when the voltage between the positive electrode 61 and the reference electrode 6 3 drops to approx. IV. At this point, the polymer exhibits a specific capacity of 19 Ah/kg polymer.

This cell is repeatedly charged and discharged under constant current conditions and exhibits good reversibility over more than 200 cycles. The cell's performance characteristics were not impaired despite repeated overdischarge and repeated overcharge in an order of magnitude corresponding to the cell's capacity. The open circuit voltage for this cell type, when examined over 4 months, showed little or no deterioration.

Example 22

The material according to example 11 is used as the positive electrode material in the cell described in example 21. A thin, electropolymerized film with an areal density of approx. 0.25 mg/ cm 2 is discharged at a current strength of approx. 0.2 5 mA/cm 2. The discharge ends when the voltage between the polymer and the reference electrode drops to approx. IV. This material has a specific capacity of 83 Ah/kg polymer.

Example 23

A porous material produced according to example 1 is used as the positive electrode material in the cell according to Fig. 1. The self-supporting film has the approximate dimensions of 2 x 0.8 x 0.1 cm and a weight of approx. 48 mg. The discharge is carried out at a total current of 2 m A and ends when the total cell voltage (between electrodes 5 and 6) drops to 1 V. This material exhibits a specific capacity of approx. 35 Ah/kg polymer and can be charged and discharged for more than 220 cycles.

Example 24

The material produced by the method according to example 15 is used as positive electrode material in the cell shown on

Fig, 2. The negative electrode material is lithium and the electrolyte 1 M LiClO. in propylene carbonate. The cell is discharged at a current of 1 mA/cm 2 , and the discharge ends when the total cell voltage drops to 1 V. The material exhibits a reversible specific capacity of 57 Ah/kg polymer.

Example 25

The material produced by the method according to example 16 is used as positive electrode material in the cell shown on

Fig. 2. The negative electrode material is lithium and . the electrolyte 1 M LiClO. in propylene carbonate. The cell is discharged at a current of 1 mA/cm 2 , and the discharge ends when the overall cell voltage drops to 1 V. The material exhibits a reversible specific capacity of 59 Ah/kg' of polymer.

Example 26

A porous material produced according to example 1 is heat treated at 80°C and an absolute pressure of approx. 1 mm Hg for 12 hours.

Example 27

Example 23 is repeated, except that the product according to example 26 is used as the positive electrode material in the cell according to Fig. 1. This material exhibits a specific capacity of approx. 57 Ah/kg polymer.

Claims (8)

1. Porous, electronically conductive material, characterized in that it comprises an electropolymerized polypyrrole or a copolymer of a pyrrole, the material being characterized by an apparent density of from 0.01 g/cm 3 up to the bulk density of the polypyrrole or copolymer and a surface area that is at least twice the surface area of a smooth film with the bulk density of the material. 2. Material according to claim 1, characterized in that it contains one or more anions with low mobility which are distinctive in that during reduction they have an average ionic transfer number of less than 0.1. 3. Process for the production of electronically conductive polypyrrole or a copolymer of pyrrole, where pyrrole or a copolymerizable mixture containing a pyrrole is electro-polymerized on an electronically conductive surface in an electrolysis bath, characterized by the steps that A, an electronically conductive surface is immersed in an electrolytic bath comprising at least one liquid and at least one immiscible liquid or gas or finely divided solid particles, in which a pyrrole or copolymerizable mixture containing a pyrrole is one of the liquids or is dissolved in at least one of the liquids, and B. an electric current is passed through the bath at a voltage sufficient to electropolymerize the pyrrole or the copolymerizable mixture containing a pyrrole on the electronically conductive surface. 4. Method according to claim 3, characterized in that an electrolysis bath is used which comprises (a) an aqueous dispersion of a pyrrole or a mixture of the aqueous dispersion and at least one copolymerizable monomer or (b) a pyrrole or a mixture of pyrrole and/or at least one copolymerizable monomer, water and a water-immiscible diluent, the bath is agitated, and an electric current is passed through the bath at a voltage sufficient to electropolymerize the pyrrole or a pyrrole mixture and deposit the polymer or copolymer on the electronically conductive surface, and the polymer or copolymer is removed from the conductive surface. 5. Method according to claim 4, characterized in that an electrolysis bath is used which also contains one or more anions with low mobility which are incorporated in the polypyrrole or in the copolymer of pyrrole and which are characterized by an average ionic transmission number during reduction of less than 0.1. 6. Method according to claim 4 or 5, characterized by the step that the electronically conductive polypyrrole or copolymer of pyrrole is heat treated to improve its electrochemical storage capacity. 7. Electrochemical cell comprising polymeric electrode devices, characterized in that the polymeric electrode devices comprise a porous, electronically conductive material that comprises an electropolymerized polypyrrole or a copolymer of pyrrole and is characterized in that it has an apparent density of from 0.01 g/cm 3 up to the spatial density of the polypyrrole or the copolymer and a surface area that is at least twice the surface area of a smooth film with the bulk density of the material. 8. Electrochemical cell according to claim 7, characterized in that the electronically conductive material contains one or more anions with low mobility which are characterized by an average ionic transfer number during reduction of less than 0.1. 9, Electrochemical cell according to claim 7 or 8, comprising a negative metal electrode device, a separator device, an electrolyte device and a polymer positive electrode device, characterized in that the polymeric positive electrode device comprises a porous, electronically conductive material comprising an electropolymerized polypyrrole or copolymer of a pyrrole and is characterized by an apparent density of from 0.1 g/cm 3 up to the spatial density of the polypyrrole or copolymer and a surface area which is at least twice the surface area of a smooth film with the bulk density of the material. 10, Electrochemical cell according to claim 9, characterized in that the material for the polymeric positive electrode device contains one or more anions with low mobility which are characterized by an average ionic transfer number during reduction of less than 0.1,