CN102668213A

CN102668213A - Membrane electrode assembly and fuel cells with increased performance

Info

Publication number: CN102668213A
Application number: CN2010800503532A
Authority: CN
Inventors: 托马斯·施密特; 山本治; 菊地淳; 小野智行; 宗内淳夫
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2009-11-06
Filing date: 2010-11-03
Publication date: 2012-09-12
Also published as: WO2011054503A1; KR20140015141A; JP2013510383A; EP2497143A1

Abstract

The present invention relates to membrane electrode assemblies comprising (i) at least two electrochemically active electrodes, (ii) said electrodes being separated by at least one polymer electrolyte membrane or electrolyte matrices, (iii) said electrodes having a catalyst layer being in contact with the above-mentioned polymer electrolyte membrane or matrices, (iv) said catalyst layer at the cathode comprising a polymer comprising the recurring units of the general formula (I) as ionomeric material and fuel cells with increased performance.

Description

Have the membrane electrode assembly and the fuel cell of strengthening the property

Technical field

The present invention relates to have the membrane electrode assembly and the fuel cell of strengthening the property, it comprises at least two electrochemical activity electrodes that separated by polymer dielectric film.

Background technology

Polymer dielectric film (PEM) fuel cell is that oneself is through known.At present, the polymer of sulfonic acid modified almost is used as proton-conductive films specially in these fuel cells.Mainly use (per) fluoropolymer here.Derive from the Nation of the DuPont de Nemours (E.I.Du Pont Company) of U.S. Wilmington ^TMIt is an one of which outstanding example.For proton conduction, in film, need high relatively water content, it reaches 4 ~ 20 hydrone/sulfonic acid groups usually.The stability of needed water content and the polymer relevant with reacting gas hydrogen with oxygen with acid water usually with the operational temperature limitation of PEM fuel cell pack at 80 ~ 100 ℃.When exerting pressure, operating temperature can be increased to greater than 120 ℃.Otherwise, can not realize higher operating temperature and not lose the power of fuel cell.

Yet,, hope that operating temperature in the fuel cell is greater than 100 ℃ because system is specific.Based on noble metal and be included in activity of such catalysts in the membrane electrode assembly (MEA) and under High Operating Temperature, significantly improve.When use was derived from the so-called reformate of hydrocarbon, reformed gas especially contained quite a large amount of carbon monoxide, and carbon monoxide must be removed by means of the gas treatment or the gas purification process of complicacy usually.Catalyst strengthens under High Operating Temperature the tolerance of CO impurity.

In addition, during fuel battery operation, produce heat.Yet, can be very complicated to being lower than 80 ℃ with these system cools.Depend on power output, can obviously construct cooling device not too complicatedly.This means obviously to be utilized in the used heat in the fuel cell system of operating under the temperature that is higher than 100 ℃ better, and therefore can strengthen efficient via the fuel cell system of generating and heating combination.

Usually, in order to realize these temperature, use film with new conductive mechanism.An approach for this purpose is to use the film that shows conductivity and need not to make water.Be disclosed in the document WO 96/13872 in the first exploitation likely of this direction.

Because the tap voltage of single fuel cell is relatively low, usually, several membrane electrode assemblies are connected in series and are connected to each other through plane clapboard (bipolar plates).

Yet in fact, current available membrane electrode assembly needs further to improve to have more emulative economical alternative to become.One of improvement that needs is the performance of reinforcing membrane electrode assemblie aspect the hydrogen reduction at the negative electrode place of membrane electrode assembly.

Summary of the invention

Therefore, the object of the present invention is to provide membrane electrode assembly and the fuel cell that has high as far as possible performance at the negative electrode place of the membrane electrode assembly that hydrogen reduction takes place.

In addition, improved membrane electrode assembly preferably should have following performance:

Fuel cell should have useful life of a specified duration as far as possible.

Should be under high as far as possible operating temperature, especially be higher than 100 ℃ and use fuel cells down.

In operation, single battery should should demonstrate constant or improved performance in the cycle of a specified duration as far as possible.

After the long operating time, fuel cell should have high as far as possible open circuit voltage and alap gas blowby.In addition, should under alap stoichiometry, operate them.

If possible, then should be able to use fuel cell and humidification fuel gas in addition.

The pressure reduction that fuel cell should be able to ground warp as well as possible must stay in lasting between anode and the negative electrode or replace.

Specifically, fuel cell should be durable to strengthen total reliability as well as possiblely to different operating condition (T, p, geometry etc.).

In addition, fuel cell should have improved temperature tolerance and corrosion resistance and low relatively gas permeability especially at high temperature.Should avoid the decline of mechanical stability and structural intergrity, especially at high temperature as well as possiblely.

These purposes are solved by the present invention.

The present invention relates to a kind of membrane electrode assembly, it comprises:

(i) at least two electrochemical activity electrodes,

(ii) said electrode is separated by at least one polymer dielectric film or electrolyte matrix,

(iii) said electrode has the catalyst layer that contacts with above-mentioned polymer dielectric film or matrix,

(iv) said catalyst layer comprises at least a ionomer material,

It is characterized in that the catalyst layer that contacts with negative electrode at least comprises the polymer as the repetitive that comprises general formula (I) of ionomer material:

Wherein (a)

Ar is identical or different and represent four covalency aromatic groups or four covalency heteroaromatic group, what they separately can be for monocycle, dicyclo or many rings, and

X is identical or different and represent N, O, S, and

R ¹Identical or different and represent two covalency groups of following formula:

And

Ar ¹, Ar ²Identical or different and represent two covalency aromatic groups or two covalency heteroaromatic group, what they separately can be for monocycle, dicyclo or many rings, and

Z ¹Identical or different and represent divalent alkyl group and/or divalent aromatic radical, in these two kinds of groups, at least one hydrogen atom is replaced by fluorine atom, and

N is 0.1 to 99.9 mole of %,

Or (b)

Ar is identical or different and represent four covalency groups of following formula:

Ar ³, Ar ⁴Identical or different and represent three covalency aromatic groups or three covalency heteroaromatic group, what they separately can be for monocycle, dicyclo or many rings, and

Z ²Identical or different and represent divalent alkyl group and/or divalent aromatic radical, in these two kinds of groups, at least one hydrogen atom is replaced by fluorine atom, and

X identical or different and represent N, O, S and

R ¹Identical or different and the representative (i) following formula two covalency groups:

And

Ar ⁵, Ar ⁶Identical or different and represent two covalency aromatic groups or two covalency heteroaromatic group, what they separately can be for monocycle, dicyclo or many rings, and

Z ³It is identical or different and represent N, O, S,

Or (ii) divalent alkyl group and/or divalent aromatic radical, these two kinds of groups can be by further replacement,

And

N is 0.1 to 99.9 mole of %.

Two supply options (a) or (b) in, preferred n is 40 to 60 moles of %, most preferably is 50 moles of %, so that quantitative (ration) between two kinds of secondary units of repetitive is quite or equal.

Two supply options (a) or (b) in, preferred X represents N or O.Most preferably in supplying option (b), X represents O.

Preferably, at Z ¹And/or Z ²In alkyl represent the short chain divalent alkyl group with 1 to 6 carbon atom, for example methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane independently of one another.

Preferably, at Z ¹And/or Z ²In alkyl represent short chain divalent alkyl group independently of one another with 1 to 6 carbon atom; For example methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane, wherein at least one carbon atom be perfluor or at least one carbon atom by at least one (CF ₃)-group, most preferably by two (CF ₃)-group replaces with formation-C (CF ₃) ₂-group.

Preferably, at Z ¹And/or Z ²In aromatic group represent divalent aromatic radical independently of one another with 5 to 6 carbon atoms; The hetero-atom that wherein one or more carbon atoms can be selected from N, O or S replaces, wherein at least one carbon atom be perfluor or at least one carbon atom by at least one (CF ₃)-group replaces; Or having the alkyl group of 2 to 6 carbon atoms, it is by at least one (CF ₃)-group, most preferably by two (CF ₃)-group replaces with formation-C (CF ₃) ₂-group or by end-C (CF ₃) ₃Group replaces.

Preferably, in supplying option (b), R ¹Representative has the divalent alkyl group of 1 to 10 carbon atom, for example methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane independently of one another.

Preferably, in supplying option (b), R ¹Representative has the divalent aromatic radical of 5 to 6 carbon atoms independently of one another, and the hetero-atom that wherein one or more carbon atoms can be selected from N, O or S replaces.

Preferred two covalency aromatic groups or two covalency heteroaromatic group Ar ¹, Ar ², Ar ⁵, Ar ⁶Representative has monocycle, dicyclo or the condensing or non-condensed aromatics or heteroaromatic ring system of encircling of 5 to 20 carbon atoms more independently of one another, and wherein one or more carbon atoms can be replaced by N, O, S.Said two covalency aromatics or two covalency heteroaromatic group Ar ¹, Ar ², Ar ⁵, Ar ⁶Can be replaced by other group.

Most preferably, two covalency aromatics or two covalency heteroaromatic group Ar ¹, Ar ², Ar ⁵, Ar ⁶Independently of one another derived from benzene, naphthalene, biphenyl, diphenyl ether, diphenyl methane, diphenyl dimethylmethane, benzophenone, diphenyl sulphone (DPS), quinoline, pyridine, bipyridine, pyridazine, pyrimidine, pyrazine, triazine, tetrazine, pyrroles, pyrazoles, anthracene, benzopyrrole, BTA, benzo

Thiadiazoles, benzo

Diazole, benzo pyridine, benzopyrazines, benzo pyridazine (benzopyrazidine), benzo pyrimidine, benzopyrazines, phentriazine, indolizine, quinolizine, pyridopyridine, imidazopyrimidine, pyrazine and pyrimidine, carbazole, ethylene imine, azophenlyene, benzoquinoline, fen Piperazine, phenthazine, acridine (acridizine), benzo pteridine, phenanthroline and phenanthrene, they are chosen wantonly and also can be substituted.

Preferred three covalency aromatics or three covalency heteroaromatic group Ar ³, Ar ⁴Representative has the fused aromatic or the heteroaromatic ring system of monocycle, dicyclo or many rings of 5 to 20 carbon atoms independently of one another, and wherein one or more carbon atoms can be replaced by N, O, S.Said three covalency aromatics or three covalency heteroaromatic group Ar ³, Ar ⁴Can be replaced by other group.

Most preferred three covalency aromatics or three covalency heteroaromatic group Ar ³, Ar ⁴Independently of one another derived from benzene, naphthalene, biphenyl, diphenyl ether, diphenyl methane, diphenyl dimethylmethane, benzophenone, diphenyl sulphone (DPS), quinoline, pyridine, bipyridine, pyridazine, pyrimidine, pyrazine, triazine, tetrazine, pyrroles, pyrazoles, anthracene, benzopyrrole, BTA, benzo

Thiadiazoles, benzo

Diazole, benzo pyridine, benzopyrazines, benzo pyridazine (benzopyrazidine), benzo pyrimidine, benzopyrazines, phentriazine, indolizine, quinolizine, pyridopyridine, imidazopyrimidine, pyrazine and pyrimidine, carbazole, ethylene imine, azophenlyene, benzoquinoline, fen

Piperazine, phenthazine, acridine (acridizine), benzo pteridine, phenanthroline and phenanthrene, they are chosen wantonly and also can be substituted.

Preferred four covalency aromatics or four covalency heteroaromatic group Ar represent monocycle, dicyclo or the condensing or non-condensed aromatics or heteroaromatic ring system of encircling with 5 to 20 carbon atoms independently of one another, and wherein one or more carbon atoms can be replaced by N, O, S.Said four covalency aromatics or four covalency heteroaromatic group Ar can be replaced by other group.

Most preferred four covalency aromatics or four covalency heteroaromatic group Ar are independently of one another derived from benzene, naphthalene, biphenyl, diphenyl ether, diphenyl methane, diphenyl dimethylmethane, benzophenone, diphenyl sulphone (DPS), quinoline, pyridine, bipyridine, pyridazine, pyrimidine, pyrazine, triazine, tetrazine, pyrroles, pyrazoles, anthracene, benzopyrrole, BTA, benzo

thiadiazoles, benzo

diazole, benzo pyridine, benzopyrazines, benzo pyridazine (benzopyrazidine), benzo pyrimidine, benzopyrazines, phentriazine, indolizine, quinolizine, pyridopyridine, imidazopyrimidine, pyrazine and pyrimidine, carbazole, ethylene imine, azophenlyene, benzoquinoline, fen piperazine, phenthazine, acridine (acridizine), benzo pteridine, phenanthroline and phenanthrene, and they are chosen wantonly and also can be substituted.

Of the present invention one preferred embodiment in, the said polymer that comprises the repetitive of general formula (I) has the repetitive of at least 10 general formulas (I), more preferably the repetitive of at least 50 general formulas (I).

Most preferably, the said polymer that comprises the repetitive of general formula (I) has the weight average molecular weight M greater than 10000 _w(through gel permeation chromatography).

Most preferably, the said polymer that comprises the repetitive of general formula (I) has the number-average molecular weight M greater than 5000 _n

Most preferably, the said polymer solubility in DMAc under 25 ℃ temperature that comprises the repetitive of general formula (I) is at least 0.5 weight %.

Ionomer material according to the present invention is present on the catalyst layer at negative electrode place with definite ratio with respect to the content of catalyst material.Catalyst, the content that is generally noble metal most are generally 0.1 to 10.0mg/cm in catalyst layer ², be preferably 0.3 to 6.0mg/cm ²And be preferably 1 especially to 4.0mg/cm ²Therefore, preferably to make weight ratio between ionomer material and catalyst be 100:1 to 1:100, most preferably be 10:1 to 1:10.Preferred especially ratio is 1:8 to 1:3.If desired, then this tittle and ratio also are applicable to the catalyst layer in anode.

The polymer that comprises the repetitive of general formula (I) can pass through following steps production:

A) in polyphosphoric acid, mix one or more aromatics two, three or tetra-amino compound and one or more aromatic carboxylic acids or its ester to form solution and/or dispersion; Each carboxylic acid monomer of said aromatic carboxylic acid or its ester is contained at least two acidic groups; Wherein said two, three or tetra-amino compound or said aromatic carboxylic acid at least a at least one fluorine atom/quilt that has fluoridize, or

In polyphosphoric acid, mix one or more aromatics diaminourea-dihydroxy compounds and one or more aromatic carboxylic acids or its ester to form solution and/or dispersion; Each carboxylic acid monomer of said aromatic carboxylic acid or its ester is contained at least two acidic groups; At least a at least one fluorine atom/quilt that has among wherein said diaminourea-dihydroxy compounds or the said aromatic carboxylic acid is fluoridized, or

In polyphosphoric acid, mix one or more aromatics and/or heteroaromatic diamino monocarboxylic acid to form solution and/or dispersion, at least a at least one the fluorine atom/quilt that has in the wherein said diamino monocarboxylic acid is fluoridized,

B) will be under inert gas from steps A) mixture be heated to and be up to 350 ℃ temperature, preferably be heated to and be up to 280 ℃ temperature, comprise the polymer of the repetitive of general formula (I) with formation.

From step B) mixture that obtains can be directly incorporates into the catalyst layer as ionomer in order to the polymer of the repetitive that will comprise general formula (I), especially incorporate into subsequently with catalyst layer that negative electrode contacts in.

In a kind of approach that supply to select, from step B) obtain mixture can be at first through polymer being precipitated and if desired, then drying is separated the non-solvent of for example water or water-bearing media.If select this approach, the polymer dissolution of repetitive that needs to comprise general formula (I) in the solvent of for example DMAc, phosphoric acid or polyphosphoric acid so that it is incorporated in the catalyst layer as ionomer, especially incorporate into subsequently with catalyst layer that negative electrode contacts in.

Proton conductive polymer electrolytes film and matrix

Known polymer dielectric film and the electrolyte matrix that is fit to the object of the invention respectively own.

Except known polymer dielectric film, electrolyte matrix also is fit to.In context of the present invention, term " electrolyte matrix " is understood that except polymer electrolyte matrices, also to refer to that wherein ion-conductive material or mixture are fixed on other host material in the matrix.For example, will mention the matrix of processing by SiC and phosphoric acid at this.

In general, use the polymer dielectric film comprise acid, wherein said acid can with the polymer covalent bond.In addition, planarization material can use acid to mix to form suitable film.

Among other method, the film of these doping can be through making thin polymer film for example with the fluid that comprises acid compound planarization material swelling or through making polymer with the mixture of acid compound and subsequently through forming flat structures, forming film production with the formation film with after coagulation.

The polymer that is fit to this purpose especially comprises polyolefin; For example gather (chlorobutadiene), polyacetylene, polyhenylene, Parylene, gather aryl methylene, polystyrene, polymethylstyrene, polyvinyl alcohol, polyvinyl acetate, polyvinylether, polyvinylamine, gather copolymer, polytrifluorochloroethylene, polyvinyl fluoride, Kynoar, polyacrolein, polyacrylamide, polyacrylonitrile, polybutylcyanoacrylate, Polymethacrylimide, cyclenes copolymer, the especially ENB of copolymer, PTEF and alkoxy carbonyl group perfluorinated alkoxy vinyl ether of copolymer, PTEF and trifluoronitrosomethane of copolymer, PTEF and the perfluoro propyl vinyl ether of (N-vinyl acetamide), polyvinyl imidazole, polyvinylcarbazole, polyvinylpyrrolidone, polyvinyl pyridine, polyvinyl chloride, Vingon, polytetrafluoroethylene, polyhexafluoropropylene, PTEF and hexafluoropropylene;

The polymer that on main chain, has the C-O key; For example polyacetals, polyformaldehyde, polyethers, PPOX, Hydrin, PolyTHF, polyphenylene oxide, polyether-ketone, polyester, especially polyglycolic acid, PETG, polybutylene terephthalate (PBT), gather hydroxybenzoate, gather ethylene lactic acid, gather pivalolactone, polycaprolactone, gather malonic acid, Merlon;

The polymer that on main chain, has the C-S key, for example polythiaether, polyphenylene sulfide, polysulfones, polyether sulfone;

The polymer that on main chain, has the C-N key for example gathers imines, gathers isocyanide, polyimide, PEI, polyaniline, Nomex, polyamide, polyhydrazide, polyurethane, polyimides, gathers azoles, gathers azoles ether ketone, polyazine;

Liquid crystal polymer, especially Vectra, and

Inorganic polymer, for example polysilane, Polycarbosilane, polysiloxanes, gather silicic acid, polysilicate, silicones, polyphosphazene and polysulfur nitride.

In this connection, preferred alkaline polymer, wherein this is particularly useful for the film with the acid doping.Nearly all known polymer film that wherein can transmit proton begins to be considered as the alkaline polymer film that mixes with acid.At this, preferably can transmit proton and need not the acid of other water, for example rely on so-called " Grotthus mechanism ".

As the alkaline polymer in context of the present invention, preferably use the alkaline polymer that in repetitive, has at least one nitrogen-atoms.

According to preferred embodiment a kind of, the repetitive in said alkaline polymer contains the aromatic ring with at least one nitrogen-atoms.Said aromatic ring is preferably five yuan or hexatomic ring with 1 to 3 nitrogen-atoms, and it can be fused to other ring, especially other aromatic ring.

According to a particular aspects of the present invention, use stable polymer at high temperature, it is in a repetitive or in different repeat units, contain at least one nitrogen, oxygen and/or sulphur atom.

In context of the present invention, the at high temperature stable polymer that is meant can be higher than under 120 ℃ the temperature as the polymer dielectric long period of operation in fuel cell." for a long time " is meant can be at least 80 ℃, preferred at least 120 ℃, operation at least 100 hours, preferably at least 500 hours under preferred at least 160 ℃ the temperature especially according to film of the present invention; And based on the initial performance that can measure according to the method in WO 01/18894A2, described, its decreased performance is not more than 50%.

Above-mentioned polymer can use separately or use as mixture (blend).At this, especially preferably contain the blend that gathers azoles and/or polysulfones.In this context, the preferred blends component be described in WO 02/36249 polyether sulfone, polyether-ketone and with the polymer of sulfonic acid group modification.Through using blend, can improve mechanical performance and can reduce material cost.

Gather the preferred especially group that azoles constitutes alkaline polymer.The repetition azoles unit that contains following general formula based on the alkaline polymer that gathers azoles: (I) and/or (II) and/or (III) and/or (IV) and/or (V) and/or (VI) and/or (VII) and/or (VIII) and/or (IX) and/or (X) and/or (XI) and/or (XII) and/or (XIII) and/or (XIV) and/or (XV) and/or (XVI) and/or (XVII) and/or (XVIII) and/or (XIX) and/or (XX) and/or (XXI) and/or (XXII)

Wherein:

Identical or different and the representative of Ar can be four covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ¹Identical or different and representative can be two covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ²Identical or different and representative can be two covalency or the three covalency aromatics or the heteroaromatic group of monocycle or many rings,

Ar ³Identical or different and representative can be three covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁴Identical or different and representative can be three covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁵Identical or different and representative can be four covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁶Identical or different and representative can be two covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁷Identical or different and representative can be two covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁸Identical or different and representative can be three covalency aromatics or heteroaromatic group of monocycle or many rings,

Ar ⁹Identical or different and representative can be two covalency or three covalency or the four covalency aromatics or the heteroaromatic group of monocycle or many rings,

Ar ¹⁰Identical or different and representative can be two covalency or the three covalency aromatics or the heteroaromatic group of monocycle or many rings,

Ar ¹¹Identical or different and representative can be two covalency aromatics or heteroaromatic group of monocycle or many rings,

X identical or different and represent oxygen, sulphur or have hydrogen atom amino group, have the group of 1 ~ 20 carbon atom, the alkyl of preferred side chain or non-side chain or alkoxy base or as the aromatic yl group of other functional group,

R is identical or different and to represent hydrogen, alkyl group and aromatic group, condition be in formula (XX), and R is not a hydrogen, and

N, m respectively do for oneself more than or equal to 10, are preferably greater than or equal 100 integer.Preferred aromatics or heteroaromatic group are derived from benzene, naphthalene, biphenyl, diphenyl ether, diphenyl methane, diphenyl dimethylmethane, benzophenone, diphenyl sulphone (DPS), quinoline, pyridine, bipyridine, pyridazine, pyrimidine, pyrazine, triazine, tetrazine, pyrroles, pyrazoles, anthracene, benzopyrrole, BTA, benzo

thiadiazoles, benzo

diazole, benzo pyridine, benzopyrazines, benzo pyridazine (benzopyrazidine), benzo pyrimidine, phentriazine, indolizine, quinolizine, pyridopyridine, imidazopyrimidine, pyrazine and pyrimidine, carbazole, ethylene imine, azophenlyene, benzoquinoline, fen

piperazine, phenthazine, acridine (acridizine), benzo pteridine, phenanthroline and phenanthrene, and they are chosen wantonly and also can be substituted.

In this case, Ar ¹, Ar ⁴, Ar ⁶, Ar ⁷, Ar ⁸, Ar ⁹, Ar ¹⁰, Ar ¹¹Can have any substitution pattern, under the situation of phenylene, Ar for example ¹, Ar ⁴, Ar ⁶, Ar ⁷, Ar ⁸, Ar ⁹, Ar ¹⁰, Ar ¹¹Can be for adjacent phenylene, metaphenylene with to phenylene.Preferred especially group is derived from benzene and inferior biphenyl, and they also can be substituted.

Preferred alkyl group is the short-chain alkyl group with 1 to 4 carbon atom, for example methyl, ethyl, n-pro-pyl or isopropyl and tertiary butyl groups.

Preferred aromatic group is the phenyl or naphthyl group.Said alkyl group and said aromatic group can be substituted.

Preferred substituted is halogen atom, for example fluorine; Amino group; Oh group; Or short-chain alkyl group, for example methyl or ethyl group.

Preferably have general formula (I) repetitive gather azoles, wherein the X of functional group in repetitive is identical.

The said azoles that gathers also can have different repetitives in principle, and for example, wherein their X of functional group is different.Yet, preferably in repetitive, only have the identical X of functional group.

Preferably gathering the azoles polymer in addition is polyimidazole; Polybenzothiozole; Polyphenyl is azoles also; Gather

diazole; Polyquinoxaline; Polythiadiazoles; Gather (pyridine); Gather (pyrimidine) and gather (four azepine pyrenes).

In another embodiment of the present invention, the said polymer that contains repetition azoles unit is copolymer or the blend that contains at least two general formulas that differ from one another (I) to the unit of (XXII).Said polymer can be the form of block copolymer (diblock, three blocks), random copolymer, periodic copolymer and/or alternating polymer.

Of the present invention one especially preferred embodiment in, the said polymer that contains repetition azoles unit is for only containing the azoles that gathers of formula (I) and/or unit (II).

The number that in said polymer, repeats the azoles unit is preferably more than or equals 10 integer.Preferred especially polymer contains at least 100 and repeats the azoles unit.

Within the scope of the invention, the polymer that preferably contains repetition benzimidazole unit.Some instances of the most useful polymer that contains repetition benzimidazole unit are expressed from the next:

Wherein n and m respectively do for oneself more than or equal to 10, are preferably greater than or equal 100 integer.

Yet employed azoles, the especially polybenzimidazoles of gathering is characteristic with the HMW.As measuring of inherent viscosity, it is preferably at least 0.2dl/g, be preferably 0.8 to 10dl/g, especially be 1 to 10dl/g.

The preparation of known this azoles of birdsing of the same feather flock together, the aromatic carboxylic acid or its ester that wherein make one or more aromatics tetra-amino compounds and one or more each carboxylic acid monomers contain at least two acidic groups react to form prepolymer with molten state.The gained prepolymer solidifies in reactor and subsequently by mechanical disintegration.The prepolymer of powdery is being up under 400 ℃ the temperature with the complete polymerization of solid-state polymerization usually.

Preferred aromatic carboxylic acid especially is dicarboxylic acids and tricarboxylic acids and tetrabasic carboxylic acid or its ester or its acid anhydrides or its acyl chlorides.The term aromatic carboxylic acid equally also comprises heteroaromatic carboxylic acids.

Preferably, said aromatic dicarboxylic acid is M-phthalic acid, terephthalic acid (TPA), phthalic acid, 5-hydroxyl M-phthalic acid, 4 hydroxyisophthalic acid, 2-hydroxyl terephthalic acid (TPA), the amino M-phthalic acid of 5-, 5-N, N-dimethylamino M-phthalic acid, 5-N; N-diethylamino M-phthalic acid, 2,5-dihydric para-phthalic acid, 2,6-dihydroxy M-phthalic acid, 4; 6-dihydroxy M-phthalic acid, 2,3-dihydroxy phthalic acid, 2,4-dihydroxy phthalic acid, 3; 4-dihydroxy phthalic acid, 3-fluorine phthalic acid, 5-fluorine M-phthalic acid, 2-fluorine terephthalic acid (TPA), ptfe phthalate, tetrafluoro M-phthalic acid, tetrafluoro terephthalic acid (TPA), 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2; 6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenic acid, 1,8-dihydroxy naphthlene-3; 6-dioctyl phthalate, diphenyl ether-4; 4'-dioctyl phthalate, benzophenone-4,4'-dioctyl phthalate, diphenyl sulphone (DPS)-4,4'-dioctyl phthalate, biphenyl-4; 4'-dioctyl phthalate, 4-trifluoromethyl phthalic acid, 2; 2-pair-(4-carboxyl phenyl) HFC-236fa, 4,4'-Stilbene dioctyl phthalate, 4-o-carboxy cinnamic acid, or its C1 ~ C20 Arrcostab or C5 ~ C12 aryl ester or its acid anhydrides or its acyl chlorides.

Aromatic tricarboxylic acid, tetrabasic carboxylic acid or its C1 ~ C20 Arrcostab or C5 ~ C12 aryl ester or its acid anhydrides or its acyl chlorides are preferably 1,3,5-benzenetricarboxylic acid (trimesic acid), 1; 2; 4-benzenetricarboxylic acid (trimellitic acid), (2-carboxyl phenyl) iminodiacetic acid, 3,5,3'-biphenyl tricarboxylic acid or 3; 5,4'-biphenyl tricarboxylic acid.

Aromatic acid or its C1 ~ C20 Arrcostab or C5 ~ C12 aryl ester or its acid anhydrides or its acyl chlorides are preferably 3,5,3', 5'-bibenzene tetracarboxylic, 1,2; 4,5-benzene tetracarboxylic acid, benzophenone tetracarboxylic acid, 3,3', 4,4'-bibenzene tetracarboxylic, 2; 2', 3,3'-bibenzene tetracarboxylic, 1,2; 5,6-naphthalenetetracarbacidic acidic or 1,4,5,8-naphthalenetetracarbacidic acidic.

Employed heteroaromatic carboxylic acids is preferably heteroaromatic dicarboxylic acids, tricarboxylic acids and tetrabasic carboxylic acid or its ester or its acid anhydrides.Heteroaromatic carboxylic acids is understood that to be meant the aromatic systems that in aromatic group, contains at least one nitrogen, oxygen, sulphur or phosphorus atoms.Preferably these are pyridines-2,5-dicarboxylic acids, pyridine-3,5-dicarboxylic acids, pyridine-2; 6-dicarboxylic acids, pyridine-2,4-dicarboxylic acids, 4-phenyl-2,5-pyridinedicarboxylic acid, 3; 5-pyrazoles dicarboxylic acids, 2,6-pyrimidine dicarboxylic acids, 2,5-pyrazine dicarboxylic acids, 2; 4,6-pyridinetricarboxylic acid or benzimidazole-5,6-dicarboxylic acids and C1 thereof ~ C20 Arrcostab or C5 ~ C12 aryl ester or its acid anhydrides or its acyl chlorides.

The content of tricarboxylic acids or tetrabasic carboxylic acid (based on employed dicarboxylic acids) is 0 to 30 mole of %, be preferably 0.1 to 20 mole of %, especially be 0.5 to 10 mole of %.

Employed aromatics and heteroaromatic diamino monocarboxylic acid are preferably diaminobenzoic acid or its mono-hydrochloric salts and dihydrochloride derivative.

The preferred mixture that uses at least two kinds of different aromatic carboxylic acids.Especially preferably use the mixture that except the aromatic carboxylic acid, also contains heteroaromatic carboxylic acids.The mixing ratio of aromatic carboxylic acid and heteroaromatic carboxylic acids is 1:99 to 99:1, be preferably 1:50 to 50:1.

These mixtures especially are the mixture of N-heteroaromatic dicarboxylic acids and aromatic dicarboxylic acid.These limiting examples is M-phthalic acid, terephthalic acid (TPA), phthalic acid, 2,5-dihydric para-phthalic acid, 2,6-dihydroxy M-phthalic acid, 4,6-dihydroxy M-phthalic acid, 2; 3-dihydroxy phthalic acid, 2,4-dihydroxy phthalic acid, 3,4-dihydroxy phthalic acid, 1,4-naphthalenedicarboxylic acid, 1; 5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, diphenic acid, 1,8-dihydroxy naphthlene-3; 6-dioctyl phthalate, diphenyl ether-4,4'-dioctyl phthalate, benzophenone-4,4'-dioctyl phthalate, diphenyl sulphone (DPS)-4,4'-dioctyl phthalate, biphenyl-4; 4'-dioctyl phthalate, 4-trifluoromethyl phthalic acid, pyridine-2,5-dicarboxylic acids, pyridine-3,5-dicarboxylic acids, pyridine-2; 6-dicarboxylic acids, pyridine-2,4-dicarboxylic acids, 4-phenyl-2,5-pyridinedicarboxylic acid, 3; 5-pyrazoles dicarboxylic acids, 2,6-pyrimidine dicarboxylic acids, 2,5-pyrazine dicarboxylic acids.

Preferred aromatics tetra-amino compound especially comprises 3,3', 4,4'-tetramino biphenyl, 2,3,5,6-4-aminopyridine, 1; 2,4,5-tetramino benzene, 3,3', 4,4'-tetramino diphenyl sulphone (DPS), 3,3'; 4,4'-tetramino diphenyl ether, 3,3', 4,4'-tetramino benzophenone, 3,3'; 4,4'-tetramino diphenyl methane and 3,3', 4,4'-tetramino diphenyl dimethylmethane with and salt, especially their mono-hydrochloric salts, dihydrochloride, tri hydrochloride and four hydrochloride derivatives.

Preferred polybenzimidazoles is to buy with trade name .

Preferred polymer comprises polysulfones, especially in main chain, has the polysulfones of aromatics and/or heteroaromatic group.According to a particular aspects of the present invention, the melt volume speed MVR 300/21.6 that measures according to ISO 1133 that preferred polysulfones and polyether sulfone have is less than or equal to 40cm ³/ 10min, especially be less than or equal to 30cm ³/ 10min and especially preferably be less than or equal to 20cm ³/ 10min.At this, the vicat softening temperature VST/A/50 that preferred polysulfones has is 180 ℃ to 230 ℃.Of the present invention another preferred embodiment in, the number-average molecular weight of polysulfones is greater than 30, the 000g/ mole.

Polymer based on polysulfones especially comprises the polymer that connects the repetitive of sulfuryl group according to having of general formula A, B, C, D, E, F and/or G:

-O-R-SO ₂-R- (A)

-O-R-SO ₂-R-O-R- (B)

-O-R-SO ₂-R-O-R-R- (C)

-O-R-SO ₂-R-R-SO ₂-R- (E)

-O-R-SO ₂-R-R-SO ₂-R-O-R-SO ₂-]?(F)

Wherein the R of functional group is identical or different independently of one another and represent aromatics or heteroaromatic group, and these functional groups at length illustrate at preceding text.These especially comprise 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 4,4'-biphenyl, pyridine, quinoline, naphthalene, phenanthrene.

Preferred within the scope of the invention polysulfones comprises homopolymers and copolymer, for example random copolymer.Preferred especially polysulfones comprises the repetitive of general formula H to N:

N＞0 wherein

N＜0 wherein

Previously described in the product name polysulfone

200P,

720P,

HTA, and The following commercially available.

In addition, special preferred, polyethers ketone, PEKK, polyether-ether-ketone, polyether ether ketone ketone and poly aryl ketone.These high-performance polymers itself are known and can be in trade name

PEEK ^TM, Under be purchased acquisition.

Above-mentioned polysulfones can provide with alkaline polymer as blend component like what stated with polyether-ketone, PEKK, polyether-ether-ketone, polyether ether ketone ketone and the poly aryl ketone mentioned.In addition; Above-mentioned polysulfones and above-mentioned polyether-ketone, PEKK, polyether-ether-ketone, polyether ether ketone ketone and poly aryl ketone can use as polymer dielectric with the sulfonation form; Wherein said sulfonation material also can be constructed the alkaline polymer as blend material, especially gathers azoles.About alkaline polymer or gather azoles and show and preferred embodiment also be applicable to these execution modes.

In order to produce thin polymer film, polymer, preferred alkaline polymer, especially gather in azoles can be dissolved in dimethylacetylamide (DMAc) for example in another step the polar non-solute, and can pass through the produced in conventional processes film.

In order to remove the solvent residues thing, described in WO 02/07518, thus obtained film can be handled with washing lotion.Because as above-mentioned patent application description clean and to gather the azoles film to remove the solvent residues thing, improved the mechanical performance of said film surprisingly.These performances especially comprise E-modulus, tearing strength and the fracture strength of film.

In addition, as in WO 02/070592 or described in the WO 00/44816, thin polymer film can be for example has other modification through crosslinked.One preferred embodiment in, as described in the WO 03/016384, the employed thin polymer film of being made up of alkaline polymer and at least a blend component contains crosslinking agent in addition.

The said thickness that gathers the azoles film can be in wide region.Preferably, before mixing with acid, the said thickness that gathers the azoles film is in 5 μ m to 2000 mu m ranges, particularly preferably in 10 μ m to 1000 mu m ranges; Yet this should not constitute restriction.

In order to realize proton conduction, with these films of acid doping.In context of the present invention, acid comprises lewis acid and the bronsted acid that all are known, preferred inorganic lewis acid and bronsted acid.

In addition, also possibly use polyacid, especially isopolyacid and heteropoly acid, and the mixture of different acid.At this; In context of the present invention; Heteropoly acid is defined as the inorganic multivariate acid with at least two different central atoms, and polynary oxyacid (polybasic oxygen acid) forms as partially mixed acid anhydrides a little less than its each free metal (preferred Cr, Mo, V, W) and nonmetal (preferred As, I, P, Se, Si, the Te).These especially comprise 12-phosphomolybdic acid and 12-phosphotungstic acid.

Said conductance of gathering the azoles film possibly influenced by doping level.Conductance rises along with dopant concentration and increases, up to reaching maximum.According to the present invention, doping level is defined as the mole of acid in every moles of polymer repetitive.Within the scope of the invention, preferred doping level is 3 to 50, especially is 5 to 40.

Preferred especially dopant is sulfuric acid and phosphoric acid or for example during hydrolysis, discharges these sour compounds.Preferred very especially dopant is phosphoric acid (H ₃PO ₄).At this, use the acid of high concentration usually.According to a particular aspects of the present invention, based on the weight of dopant, concentration of phosphoric acid is at least 50 weight %, especially be at least 80 weight %.

In addition, proton-conductive films also can obtain through the method that may further comprise the steps:

I) with polymer, especially gather azoles and be dissolved in the phosphoric acid,

II) can be under inert gas according to steps A) mixture that obtains is heated to and is up to 400 ℃ temperature,

III) use according to Step II) the solution of polymer on carrier, forms film and

IV) handle at Step II I) in the film of formation, up to its self-supporting.

In addition, the azoles film that gathers of doping can obtain through the method that may further comprise the steps:

A) in polyphosphoric acid, mix one or more aromatics tetra-amino compounds and one or more aromatic carboxylic acids or its ester to form solution and/or dispersion; Each carboxylic acid monomer of said aromatic carboxylic acid or its ester is contained at least two acidic groups; Or in polyphosphoric acid, mix one or more aromatics and/or heteroaromatic diamino monocarboxylic acid to form solution and/or dispersion

B) use according to steps A) mixture carrier or electrode are applied one deck,

C) can be under inert gas according to step B) flat structures/layer of obtaining is heated to and is up to 350 ℃ temperature, preferably is heated to be up to 280 ℃ temperature, and formation gathers the azoles polymer,

D) handle at step C) in the film (up to its self-supporting) of formation.

Preceding text have been described will be used for steps A) aromatics or heteroaromatic carboxylic acids and tetra-amino compound.

Be used for steps A) polyphosphoric acid be the polyphosphoric acid commonly used that can for example buy from Riedel-de Haen.With P ₂O ₅(through acidimetry) calculated, polyphosphoric acid H _N+2P _nO _3n+1(n>L) concentration is generally at least 83%.Also can production dispersion/suspended substance rather than the solution of monomer.

In steps A) in the mixture produced, the weight ratio of polyphosphoric acid and all monomer summations is 1:10,000 to 10,000:1, be preferably 1:1000 to 1000:1, especially be 1:100 to 100:1.

According to step B) layer form through own means known in the prior art of producing (cast, spray, apply) and carry out with scraper at thin polymer film.The every kind of carrier that is considered to inertia under the described conditions all is suitable as carrier.In order to regulate viscosity, if desired, then can phosphoric acid (85% SPA) be added in the said solution.Therefore, can be with the formation of viscosity adjustment to desirable value and promotion film.

According to step B) thickness of the layer produced is 10 to 4000 μ m, be preferably 20 to 4000 μ m, very preferably be 30 to 3500 μ m, especially be 50 to 3000 μ m.

If according to steps A) mixture also contain tricarboxylic acids or tetrabasic carboxylic acid, then utilize the branching of its polymer that can realize forming/crosslinked.This helps to improve mechanical performance.In the presence of the moisture under suitable temperature, according to step C) processing of the polymeric layer produced carries out time enough, demonstrates the enough intensity that is used for fuel cell up to this layer.Can carry out the degree that this processing reaches the film self-supporting, make this film to separate and have no destruction with carrier.

According to step C), will be at step B) in the flat structures that obtains be heated to and be up to 350 ℃, preferably be up to 280 ℃ and preferred especially 200 ℃ to 250 ℃ temperature.Be used for step C) inert gas be that those of ordinary skills are known.These especially comprise the nitrogen and the rare gas of neon, argon, helium for example.

In a variant of this method, through will be from steps A) mixture that obtains is heated to and is up to 350 ℃, preferably is up to 280 ℃ temperature, can form oligomer and/or polymer.Depend on chosen temperature and duration, then at step C) in can partially or completely omit heating.This variant also is an one object of the present invention.

At step D) in the processing of film greater than 0 ℃ but under, preferably between 10 ℃ to 120 ℃, especially under the temperature between room temperature (20 ℃) is to 90 ℃ less than 150 ℃ temperature, carry out having moisture or water and/or steam and/or be up under the situation of 85% water-bearing phosphate.This processing is preferably carried out under normal pressure, but also can carry out under pressure.Necessary is to handle in the presence of enough moistures, to carry out, and the polyphosphoric acid that exists thus forms the low-molecular-weight polyphosphoric acid through partial hydrolysis and/or phosphoric acid helps solidifying of this film.

The hydrolysis fluid can also contain the solution of the composition that suspends and/or disperse for this fluid wherein.The viscosity of hydrolysis fluid can be in wide region, and the rising of adding or temperature that wherein can carry out solvent is to regulate viscosity.Dynamic viscosity is preferably 0.1 to 10, and in the 000mPa*s scope, especially in 0.2 to 2000mPa*s scope, wherein these values can for example be measured according to DIN 53015.

According to step D) processing can enough any known process carry out.Can be with at step C) in the film that obtains for example be immersed in the bath.In addition, can the hydrolysis fluid be sprayed on the film.In addition, can the hydrolysis fluid be poured on the film.The advantage of back one method is that the concentration of acid in the hydrolysis fluid keeps constant during hydrolysis.Yet first method is usually more cheap in practice.

The oxyacid of phosphorus and/or sulphur especially comprises phosphinic acids, phosphonic acids, phosphoric acid, connects di 2 ethylhexyl phosphonic acid, hypophosphoric acid, few phosphoric acid, sulfurous acid, two sulfurous acid and/or sulfuric acid.These acid can be used separately or use as mixture.

In addition, the oxyacid of phosphorus and/or sulphur comprises the monomer that can process and comprise phosphonic acids and/or sulfonic acid group through radical polymerization.

The monomer that comprises phosphonate group is known in the art.These monomers are the compound with at least one carbon-to-carbon double bond and at least one phosphonate group.Preferably, two carbon atoms that form carbon-to-carbon double bond have at least two, preferred 3 keys and are attached to group, and this causes lower sterically hindered of two keys.These groups especially comprise hydrogen atom and halogen atom, especially fluorine atom.Within the scope of the invention, the polymer that comprises phosphonate group is by comprising the monomer of phosphonate group through polymerization only or making the monomer that comprises phosphonate group and polymerizate that other monomer and/or crosslinking agent polymerization obtain produces.

The monomer that comprises phosphonate group can comprise one, two, three or more a plurality of carbon-to-carbon double bond.In addition, the monomer that comprises phosphonate group can contain one, two, three or more a plurality of phosphonate group.

In general, the monomer that comprises phosphonate group contains 2 to 20, preferred 2 to 10 carbon atoms.

The monomer that comprises phosphonate group is preferably the compound of following formula:

Wherein:

R represents key, two covalency C1 ~ C15 alkylidene group, two covalency C1 ~ C15 alkylene oxide group group such as ethyleneoxy group group or two covalency C5 ~ C20 aryl or heteroaryl groups, wherein above-mentioned functional group itself can by halogen ,-OH, COOZ ,-CN, NZ ₂Replace,

Z represents hydrogen, C1 ~ C15 alkyl group, C1 ~ C15 alkylene oxide group group, ethyleneoxy group group or C5 ~ C20 aryl or heteroaryl groups independently of one another, wherein above-mentioned functional group itself can by halogen ,-OH ,-CN replaces, and

X represents integer 1,2,3,4,5,6,7,8,9 or 10,

Y represents integer 1,2,3,4,5,6,7,8,9 or 10,

And/or the compound of following formula:

Wherein:

Z represents hydrogen, C1 ~ C15 alkyl group, C1 ~ C15 alkoxy base, ethyleneoxy group group or C5 ~ C20 aryl or heteroaryl groups independently of one another, wherein above-mentioned functional group itself can by halogen ,-OH ,-CN replaces, and

X represents integer 1,2,3,4,5,6,7,8,9 or 10,

And/or the compound of following formula:

Wherein:

A represents general formula COOR ², CN, CONR ² ₂, OR ²And/or R ²Group, R wherein ²Be hydrogen, C1 ~ C15 alkyl group, C1 ~ C15 alkoxy base, ethyleneoxy group group or C5 ~ C20 aryl or heteroaryl groups, wherein above-mentioned functional group itself can by halogen ,-OH, COOZ ,-CN, NZ ₂Replace,

X represents integer 1,2,3,4,5,6,7,8,9 or 10.

The preferred monomers that comprises phosphonate group especially comprises the alkene that contains phosphonate group, such as vinyl phosphate, acrylic phosphate, cyclobutenyl phosphate; The acyclic compound and/or the methacrylic compound that contain phosphonate group, for example 2-phosphinomethyl acrylic acid, 2-phosphinomethyl methacrylic acid, 2-phosphinomethyl acrylamide and 2-phosphinomethyl Methacrylamide.

The preferred especially vinyl phosphonate (vinyl phosphate) that is purchased that uses for example, is buied from for example Aldrich or Clariant GmbH company.The purity of preferred vinyl phosphonate is higher than 70%, especially be higher than 90% and especially preferably be higher than 97%.

The monomer that comprises phosphonate group can use with the derivative form that can change into acid subsequently in addition, and wherein the conversion of acid also can take place under polymerization state.These derivatives especially comprise salt, ester, acid amides and the halide of the monomer that comprises phosphonate group.

In addition, also can the monomer that comprise phosphonate group be guided on the film after the hydrolysis and introduce in this film.This can be through carrying out from the known own means known of prior art (for example spraying, impregnating).

According to a particular aspects of the present invention, the weight summation of the hydrolysate of phosphoric acid, polyphosphoric acid and polyphosphoric acid and monomer that can be through radical polymerization processing, as the ratio of the weight of the monomer that comprises phosphonate group be preferably greater than or equal 1:2, especially more than or equal to 1:1 and be preferably greater than especially or equal 2:1.

The ratio of the weight summation of the hydrolysate of preferably phosphoric acid, polyphosphoric acid and polyphosphoric acid and the weight of the monomer that can process through radical polymerization is in 1000:1 to 3:1 scope, especially in 100:1 to 5:1 scope and particularly preferably in 50:1 to the 10:1 scope.

This ratio can easily be measured through common method, and wherein, under many circumstances, phosphoric acid, polyphosphoric acid and hydrolysate thereof can be washed off from film.Thus, the weight of polyphosphoric acid and hydrolysate thereof can obtain after complete hydrolysis becomes phosphoric acid.In general, this also be applicable to can be through the monomer of radical polymerization processing.

Comprising sulfonic monomer is known in the art.These monomers are for having at least one carbon-to-carbon double bond and at least one sulfonic compound.Preferably, two carbon atoms that form carbon-to-carbon double bond have at least two, preferred 3 keys and are attached to group, and this causes lower sterically hindered of two keys.These groups especially comprise hydrogen atom and halogen atom, especially fluorine atom.Within the scope of the invention, comprising sulfonic polymer comprises the polymerizate that sulfonic monomer and other monomer and/or crosslinking agent polymerization obtain and produces by comprising sulfonic monomer through polymerization only or making.

Comprise sulfonic monomer and can comprise one, two, three or more a plurality of carbon-to-carbon double bond.In addition, comprise sulfonic monomer and can contain one, two, three or more a plurality of sulfonic group.

In general, comprise sulfonic monomer and contain 2 to 20, preferred 2 to 10 carbon atoms.

Comprise the compound that sulfonic monomer is preferably following formula:

Wherein:

X represents integer 1,2,3,4,5,6,7,8,9 or 10,

Y represents integer 1,2,3,4,5,6,7,8,9 or 10,

And/or the compound of following formula:

Wherein:

R represents singly-bound, two covalency C1 ~ C15 alkylidene group, two covalency C1 ~ C15 alkylene oxide group group such as ethyleneoxy group group or two covalency C5 ~ C20 aryl or heteroaryl groups, wherein above-mentioned functional group itself can by halogen ,-OH, COOZ ,-CN, NZ ₂Replace,

X represents integer 1,2,3,4,5,6,7,8,9 or 10,

And/or the compound of following formula:

Wherein:

X represents integer 1,2,3,4,5,6,7,8,9 or 10.

Comprise sulfonic preferred monomers and especially comprise and contain sulfonic alkene, for example vinyl sulfonic acid ester, acrylic sulphonic acid ester, cyclobutenyl sulphonic acid ester; Contain sulfonic acyclic compound and/or methacrylic compound, for example 2-sulfo group methacrylic acid, 2-sulfo group methyl acrylic acid, 2-sulfo group Methacrylamide and 2-sulfo group methyl acrylamide.

The preferred especially vinyl sulfonic acid (vinyl sulfonic acid ester) that is purchased that uses is for example buied from for example Aldrich or Clariant GmbH company.The purity of preferred vinyl sulfonic acid is higher than 70%, especially be higher than 90% and especially preferably be higher than 97%.

Comprise sulfonic monomer and can use with the derivative form that can change into acid subsequently in addition, wherein the conversion of acid also can take place under polymerization state.These derivatives especially comprise salt, ester, acid amides and the halide that comprises sulfonic monomer.

In addition, also can guide on the film after the hydrolysis and introduce in this film comprising sulfonic monomer.This can be through carrying out from the known own means known of prior art (for example spraying, impregnating).

In another embodiment of the present invention, can use can be crosslinked monomer.Can these monomers be added in the hydrolysis fluid.In addition, also can be with being applied on the film that after hydrolysis, obtains by crosslinked monomer.

Monomer that can be crosslinked is especially for having the compound of at least two carbon-to-carbon double bonds.Preferred diene, triolefin, tetraene, dimethylacrylate, trimethyl acrylic ester, tetramethyl acrylic acid ester, diacrylate, triacrylate, tetraacrylate.

Diene, triolefin, the tetraene of preferred especially following formula:

The dimethylacrylate of following formula, trimethyl acrylic ester, tetramethyl acrylic acid ester:

The diacrylate of following formula, triacrylate, tetraacrylate:

Wherein:

R represent C1 ~ C15 alkyl group, C5 ~ C20 aryl or heteroaryl groups, NR' ,-SO ₂, PR', Si (R') ₂, wherein above-mentioned functional group itself can be substituted,

R' represents hydrogen, C1 ~ C15 alkyl group, C1 ~ C15 alkoxy base, C5 ~ C20 aryl or heteroaryl groups independently of one another, and

N is at least 2.

The substituting group of the above-mentioned R of functional group is preferably halogen, hydroxyl, carboxyl (carboxy), carboxyl (carboxyl), carboxyl ester, nitrile, amine, silicyl, siloxy group group.

Special preferred cross-linking agents is allyl methacrylate, GDMA, diethyleneglycol dimethacrylate, dimethacrylate triglycol ester, dimethacrylate TEG ester and dimethacrylate macrogol ester, dimethacrylate 1; 3-butanediol ester, dimethyl allene acid glyceride, two urea alkane dimethylacrylates, trimethyl propane trimethyl acrylic ester, epoxy acrylate such as ebacryl, Ν ', Ν-methylene-bisacrylamide, methyl alcohol, butadiene, isoprene, chlorobutadiene, divinylbenzene and/or bisphenol a dimethacrylate.These compounds can be from for example Sartomer Company (U.S. Sartomer company) Exton, and Pennsylvania (Pennsylvania) buys under title CN120, CN104 and CN980.

The optional crosslinking agent that uses, wherein, based on the weight of film, these compounds can use with 0.05 to 30 weight %, preferred 0.1 to 20 weight %, preferred especially 1 to 10 weight % usually.

Can said cross-linking monomer be guided on the film after the hydrolysis and introduce in this film.This can be through carrying out from the known own means known of prior art (for example spraying, impregnating).

According to a particular aspects of the present invention, the monomer or the cross-linking monomer that comprise phosphonic acids and/or sulfonic acid group can polymerizations, and wherein this polymerization is preferably radical polymerization.The formation of free radical can heat, photochemistry, chemistry and/or electrochemistry take place.

For example, can be added in the hydrolysis fluid containing at least a startup solution that can form the material of free radical.In addition, can be applied on the hydrolysis film afterwards starting solution.This can be through carrying out from the known own means known of prior art (for example spraying, impregnating).

It especially is azo-compound, per-compound, persulfate compound or azo amidine that suitable free radical forms thing.Limiting examples is dibenzoyl peroxide, cumyl peroxide, hydrogen phosphide cumene, di-isopropyl peroxydicarbonate, two (4-tert-butylcyclohexyl) esters of peroxy dicarbonate, persulfuric acid dipotassium, peroxo disulfate acid ammonium, 2; 2'-azo two (2-methyl propionitrile) (AIBN), 2; Two (isobutyric acid amidine) hydrochlorides of 2'-azo, benzpinacol, dibenzyl derivative, peroxidating ethylene methacrylic ketone, 1; 1-azo bis cyclohexane formonitrile HCN, methyl ethyl ketone peroxide, diacetone peroxide, dilauroyl peroxide, peroxide two caprinoyls, the peroxidating 2 ethyl hexanoic acid tert-butyl ester, ketone peroxide, peroxidating methyl iso-butyl ketone (MIBK), cyclohexanone peroxide, dibenzoyl peroxide, peroxidized t-butyl perbenzoate, tert-butylperoxy isopropyl carbonate, 2; Two (peroxidating of 2-ethyl hexanoyl)-2 of 5-; 5-dimethylhexane, peroxide-2-ethyl hexanoic acid tert-butyl, peroxidating-3; 5; The 5-tri-methyl hexanoic acid tert-butyl ester, peroxidating tert-butyl isobutyrate, peroxide acetic acid butyl ester, cumyl peroxide, 1; 1-bis(t-butylperoxy) cyclohexane, 1; 1-bis(t-butylperoxy)-3; 3,5-trimethyl-cyclohexane, hydrogen phosphide cumene, t-butyl hydroperoxide, two (4-tert-butylcyclohexyl) peroxy dicarbonate and form thing in title

like the free radical of buying under

V50 and

WS from DuPont.

In addition, also can use the free radical that when being exposed to radiation, forms free radical to form thing.Preferred compound especially comprises α; α-diethoxy acetophenone (DEAP; Upjon Corp), styrax n-butyl ether (

-14; AKZO) and 2; 2-dimethoxy-2-phenyl acetophenone (

651) and 1-benzoyl cyclohexanol (

184), two (2; 4; The 6-trimethylbenzoyl) phenyl phosphine oxide (

819) and 1-[4-(2-hydroxyl-oxethyl) phenyl]-2-hydroxyl-2-phenyl third-1-ketone (

2959), it is buied from the Ciba Geigy Corp of company separately.

Usually add 0.0001 to 5 weight %, especially 0.01 to 3 weight % is (respectively based on the monomer that can process through radical polymerization; The weight that comprises phosphonate group and/or sulfonic monomer or cross-linking monomer) free radical forms thing.The amount that free radical forms thing can change according to the required degree of polymerization.

Polymerization also can be passed through IR or NIR respectively, and (the IR=infrared light promptly has the light greater than the wavelength of 700nm; The NIR=near infrared light promptly has the light of about wavelength of 700 to 2000nm and about energy of 0.6 to 1.75eV) effect take place.

Polymerization also can take place through the effect that has less than the ultraviolet light of the wavelength of 400nm.This polymerization itself is known and for example in following document, describe: Hans Joerg Elias, Makromolekulare Chemie (polymer chemistry), the 5th edition, the 1st volume, the 492nd ~ 511 page; D.R.Arnold, N.C.Baird, J.R.Bolton; J.C.D.Brand, P.W.MJacobs, P.de Mayo; W.R.Ware; Photochemistry-An Introduction (photochemistry introduction), Academic Press (academic press), New York (New York) and M.K.Mishra; Radical Photopolymerization of Vinyl Monomers (radical photopolymerization of vinyl monomer), J.Macromol.Sci.-Revs.Macromol.Chem.Phys.C22 (1982 ~ 1983) 409.

Polymerization also can take place through being exposed to β ray, gamma-rays and/or electron ray.According to a specific implementations of the present invention, with film with 1 to 300kGy, preferred 3 to 200kGy and preferred very especially 20 to 100kGy radiation dose irradiation.

The polymerization that comprises phosphonate group and/or sulfonic monomer or cross-linking monomer is respectively preferably under being higher than room temperature (20 ℃) and being lower than 200 ℃ temperature, especially take place under 40 ℃ to 150 ℃, preferred especially 50 ℃ to 120 ℃ temperature.Said polymerization is preferably carried out under normal pressure, but also can carry out under pressure.This polymerization causes that flat structures solidifies, and wherein this solidifies and can observe via measuring microhardness.Preferably, based on the hardness of the corresponding hydrolysis film that does not have monomer polymerization, the hardness that is caused by polymerization strengthens at least 20%.

According to a particular aspects of the present invention, the mol ratio of the molal quantity summation of the hydrolysate of phosphoric acid, polyphosphoric acid and polyphosphoric acid and phosphonate group and/or sulfonic molal quantity in the polymer that obtains with monomer through comprising phosphonate group and/or the polymerization that comprises sulfonic monomer be preferably greater than or equal 1:2, especially more than or equal to 1:1 and be preferably greater than especially or equal 2:1.

The mol ratio of the molal quantity summation of the hydrolysate of preferably phosphoric acid, polyphosphoric acid and polyphosphoric acid and phosphonate group and/or sulfonic molal quantity in the polymer that monomer that can be through comprising phosphonate group and/or the polymerization that comprises sulfonic monomer obtain preferably in 1000:1 to 3:1 scope, especially in 100:1 to 5:1 scope and in particularly preferably in 50:1 to 10:1 scope.

Mol ratio can be measured through common method.For this reason, can use spectroscopic method especially, for example the NMR spectroscopic methodology.In this connection, must consider that phosphonate group exists with formal oxidation attitude 3, and the phosphorus in phosphoric acid, polyphosphoric acid or its hydrolysate exists with oxidation state 5 respectively.

Depend on the required degree of polymerization, the flat structures that after polymerization, obtains is a self-supported membrane.Preferred degree of polymerization at least 2 repetitives, especially at least 5 repetitives, especially be preferably at least 30 repetitives, especially at least 50 repetitives, be preferably at least 100 repetitives very especially.This degree of polymerization is via number-average molecular weight M _nMeasure number-average molecular weight M _nCan measure through the GPC method.Be a problem owing under the situation of not degrading, separate the polymer that comprises phosphonate group that is included in the film, this value is by means of under the situation that does not add polymer, measuring through the sample that makes the monomer polymerization acquisition that comprises phosphonate group.In this connection, compare, comprise the monomer of phosphonate group and the part by weight of radical initiator (radical starter) and keep constant with the ratio of film production.Based on the employed monomer that comprises phosphonate group, the conversion ratio of in polymerization relatively, realizing be preferably greater than or equal 20%, especially more than or equal to 40% and be preferably greater than especially or equal 75%.

The hydrolysis fluid comprises water, and wherein the concentration of water is not crucial especially usually.According to a particular aspects of the present invention, the hydrolysis fluid comprises the water of 5 to 80 weight %, preferred 8 to 70 weight % and preferred especially 10 to 50 weight %.In the water content of hydrolysis fluid, do not consider to be included in the amount of the water in the oxyacid in form.

In above-mentioned acid, special preferably phosphoric acid and/or sulfuric acid, wherein these acid comprise the especially water of 5 to 70 weight %, preferred 10 to 60 weight % and preferred especially 15 to 50 weight %.

At step D) in the partial hydrolysis of polyphosphoric acid solidify owing to sol-gel transition causes film.This also reduces 15 to 3000 μ m, preferred 20 to 2000 μ m with layer thickness, especially 20 to 1500 μ m are associated, and this film is a self-supporting.

According to step B) the polyphosphoric acid layer in cause at step C with intermolecular structure (interpenetrating networks IPN) in the molecule that exists) in the orderly film of formation, it is determining the special properties of the film that forms.

According to step D) the treatment temperature upper limit be generally 150 ℃.Under the situation from the extremely of short duration effect of the moisture of superheated steam for example, this steam also can be higher than 150 ℃.The upper limit of the duration of this processing for temperature is important.

Partial hydrolysis (step D) also can take place in the environmental chamber, and wherein this hydrolysis can utilize definite moisture effect to control particularly.In this connection, humidity can be via for example the temperature or the saturation of the peripheral region that contacts of air, nitrogen, carbon dioxide or other suitable gas or steam are set particularly with gas for example.The duration of handling is depended on the parameter of above-mentioned selection.

In addition, the duration of processing is depended on the thickness of film.

Usually, for example under the superheated steam effect, the duration of processing amounts to several seconds to a few minutes, perhaps for example in the open room temperature and than under the low relative humidity up to a couple of days.Preferably, the duration of processing is 10 seconds to 300 hours, especially 1 minute to 200 hours.

If partial hydrolysis is carried out under room temperature (20 ℃), in the surrounding air of relative humidity 40 ~ 80%, the duration of then handling is 1 to 200 hour.

According to step D) film that obtains can form by this way, but so that its self-supporting, promptly it can separate with carrier and has no destruction, and if subsequently suitably, directly further process.

Concentration of phosphoric acid can be regulated via hydrolysis degree with the conductivity of polymer film therefore, promptly regulates via duration, temperature and ambient humidity.Concentration of phosphoric acid provides with the sour mole in every moles of polymer repetitive.Can be through comprising steps A) to D) method obtain film with special high concentrations of phosphoric acid.Preferred concentrations (mole of phosphoric acid is based on the repetitive of general formula (I), for example polybenzimidazoles) is 10 to 50, especially 12 to 40.Gather azoles through mixing and only can realize under the situation of difficult very much, perhaps can not realize fully to obtain high like this doping level (concentration) with commercially available orthophosphoric acid.

Through using the modification of the institute's describing method that gathers the azoles film that polyphosphoric acid production mixes, the production of these films can be carried out through the method that may further comprise the steps according to wherein:

1) is being up to 350 ℃, preferably is being up under 300 ℃ the temperature and makes one or more aromatics tetra-amino compounds and one or more aromatic carboxylic acids or the reaction of its ester with molten state; Perhaps make one or more aromatics and/or assorted fragrant diamino monocarboxylic acid reaction; Each carboxylic acid monomer of said aromatic carboxylic acid or its ester is contained at least two acidic groups

2) will be dissolved in according to the solid prepolymer that step 1) obtains in the polyphosphoric acid,

3) can be under inert gas according to step 2) solution that obtains is heated to and is up to 300 ℃, preferably is up to 280 ℃ temperature, and what form dissolving gathers the azoles polymer,

4) use the solution that gathers the azoles polymer according to step 3) on carrier, forms film and

5) handle the film that in step 4), forms, up to its self-supporting.

1) to 5) method step of describing down, oneself is through in front for steps A) to D) illustrated details, here can reference, especially reference is preferred embodiment.

Film, particularly based on the film that gathers azoles, can be further crosslinked through heat effect in the presence of aerial oxygen on the surface.The sclerosis on this film surface has further improved the character of film.For this purpose, can film be heated at least 150 ℃, preferred at least 200 ℃ and preferred at least 250 ℃ temperature especially.In this step of said method, oxygen concentration usually in 5 to 50 volume % scopes, preferably in 10 to 40 volume % scopes; Yet this should not constitute restriction.

Crosslinked also can be respectively through IR or NIR (the IR=infrared light, promptly wavelength is greater than the light of 700nm; The NIR=near infrared light, promptly wavelength be about 700 to 2000nm and energy be about light of 0.6 to 1.75eV) effect take place.Another method is the beta rays irradiation.In this connection, exposure dose is 5 to 200kGy.

Depend on the required degree of cross linking, the duration of cross-linking reaction can be in wide region.In general, this reaction time is in 1 second to 10 hours scope, preferably in 1 minute to 1 hour scope; Yet this should not constitute restriction.

Preferred especially polymer film demonstrates high-performance.This reason especially is improved proton conductivity.This proton conductivity under 120 ℃ temperature for 1mS/cm at least, be preferably at least 2mS/cm, especially be 5mS/cm at least.At this, these values can obtain under nonwetting situation.Therefore, said film is suitable as so-called high temperature polymer electrolyte membrane fuel cell and in order to production high temperature membrane electrode assemblie.Above-mentioned high temperature proton conductivity can be realized through acid that comprises (i) alkaline polymer material or matrix and permission so-called " Grotthus mechanism " or proton conductive polymer electrolytes film and the matrix that (ii) has the polymeric material of the covalent bond group that allows so-called " Grotthus mechanism ".Under one situation of back, this realizes through the above-mentioned polymer of monomers derived from comprising phosphonate group of incorporating 10 weight % into usually at least.

Pass through in the configuration of 4 utmost points, to measure than conductivity with the impedance spectrum of potentiostatic mode and use platinum electrode (electric wire, diameter 0.25mm).Gap between collecting electrodes is 2cm.The spectrum that is obtained uses the naive model assessment of being made up of the parallel connection configuration of Ohmic resistance and capacitor.Cross section with phosphate-doped membrane sample was directly measured before sample is installed.In order to measure temperature dependency, make and measure battery reaches temperature required and uses the configuration of next-door neighbour's sample in baking oven Pt-100 thermocouple adjusting.In case reach this temperature, sample remained under this temperature 10 minutes.

Gas diffusion layers

Membrane electrode assembly according to the present invention has two gas diffusion layers that separated by polymer dielectric film.

Very light, may not conduct electricity but mechanically stable and for example contain the mechanically stable material of the fiber of supatex fabric, paper or Woven fabric form and use raw material as gas diffusion layers according to the present invention.These for example comprise papyrex, carbon fiber paper, graphite cloth and/or give the paper of conductivity through adding carbon black.Through these layers, realize the FINE DISTRIBUTION of gas and/or flow of liquid.

The material of said mechanically stable preferably contains carbon fiber, glass fiber or contains the for example fiber of the organic polymer of polypropylene, polyester (PETG), polyphenylene sulfide or polyether-ketone, more than just lists out several kinds of examples.In this connection, per unit area weight<150g/>m ², preferably 10 to 100g/m ²Material in the scope is particularly suitable for.

When using material with carbon element as stabilizing material, the supatex fabric of being processed by carbonization or graphitized fibre with the per unit area weight in preferable range is particularly suitable for.Use this type material to have two advantages: at first, they are very light, and secondly, they have high opening rate.

The percent opening of the preferred stabilizing material that uses in 20 to 99.9% scopes, preferably in 40 to 99% scopes, make they can with other material easily fill and porosity, conductivity and the hydrophobicity of finished product gas diffusion layers therefore can be with direct mode, promptly run through the whole thickness adjusted of gas diffusion layers.

In general, the thickness of this layer is 80 μ m to 2000 μ m, especially is 100 μ m to 1000 μ m and is preferably 150 μ m to 500 μ m especially.

The production of gas diffusion layers or gas-diffusion electrode is for example being described in detail among the WO 97/20358.The production method of statement also is the part of this specification therein.

In order to reduce surface tension, for example, can add material (additive or washing agent) like what in WO 97/20358, describe in detail.In addition, the hydrophobicity of gas diffusion layers can be set through using perfluorinated polymers and nonfluorinated binding agent.Subsequently, the gas diffusion layers of equipment is dry also for example through coming after-baking at the sintering temperature that is higher than 200 ℃.

In addition, can construct gas diffusion layers with several layers.One of gas diffusion layers preferred embodiment in, it has at least two can distinguish layer.With 4 layers of upper limit that is regarded as the multi-layer gas diffusion layer.If use, then make these layers form tight the connection each other through preferred compression or lamination step under higher temperature easily more than one deck.Through using the multi-layer gas diffusion layer, can generate preset (pre-trimmed) layer, can set effective drainage porosity and/or hydrophobic gradient through this preset layer.This type gradient also can apply or the impregnation steps generation through several continuously, yet its enforcement is more bothersome usually.

According to a specific execution mode, one deck at least of gas diffusion layers can be made up of compressible material.Within the scope of the invention, the characteristics of compressible material be gas diffusion layers may be compressed to its original thickness half the, especially 1/3rd and do not lose the character of its integrality.

Gas diffusion layers according to the present invention has<100mOhm/>cm ², preferred<60mOhmcm ²Low surface resistivity.

This character demonstrates through the gas diffusion layers of being processed by graphite cloth and/or graphite paper usually, and this gas diffusion layers is endowed conductivity through adding carbon black.This gas diffusion layers is also optimised aspect its hydrophobicity and mass-transfer performance through adding other material usually.In this connection, gas diffusion layers is equipped with and fluoridizes or partially fluorinated material, for example PTFE.

Catalyst layer

Said one or more catalyst layer contains catalytic active substance.These materials especially comprise the platinum family noble metal, i.e. Pt, Pd, Ir, Rh, Os, Ru or other noble metal Au and Ag.In addition, also can use the alloy of all above-mentioned metals.In addition, at least one catalyst layer can contain platinum family element and for example non-noble metal alloys such as Fe, Co, Ni, Cr, Mn, Zr, Ti, Ga, V.In addition, also can use above-mentioned noble metal and/or non-noble metal oxide.Can be with the catalytic activity particle that comprises above-mentioned substance as metal dust, especially platinum and/or platinum alloy powder, so-called black noble metal use.The size of this type particle is generally 5nm to 200nm, is preferably 7nm to 100nm.Also use so-called nano particle.

In addition, also can said metal be used on the carrier material.Preferred this carrier comprises carbon, and this carbon especially can use with the form of carbon black, graphite or ketjenblack EC.In addition, can be with conducting metal oxide, SnO for example _x, TiO _xOr phosphate, for example FePO _x, NbPO _x, Zr _y(PO _x) _zAs carrier material.In this connection, mark x, y and z indicate the oxygen or the tenor of independent compound, because transition metal can have the different oxidation attitude, so they can be in known range.

Based on the total weight of the combination of metal and carrier, the content of these metallics on carrier is generally 1 to 80 weight %, is preferably 5 to 60 weight % and is preferably 10 to 50 weight % especially; Yet this should not constitute restriction.The size of carrier particle, especially carbon particle be preferably dimensioned to be 20 to 1000nm, especially be 30 to 100nm.The metallic that exists above that is preferably dimensioned to be 1 to 20nm, especially be 1 to 10nm and be preferably 2 especially to 6nm.

The size of different particles is represented mean value and can be measured via transmission electron microscopy or X-ray powder diffraction art.

More than the catalytic activity particle of statement can be commercially available usually.

Except the catalyst that can be purchased or the catalyst particle; Can also use by the catalyst nanoparticles that contains platinum alloy, processes based on the alloy of Pt, Co and Cu or Pt, Ni and Cu especially respectively, the Pt content in the shell of said particle is higher than the Pt content in its nuclear.This type particle is described in Angewandte Chemie 2007 (applied chemistry 2007) by people such as P.Strasser.

In addition, catalytic active layer can contain additive commonly used.These additives especially comprise fluoropolymer such as polytetrafluoroethylene (PTFE), proton conduction ionomer and surface reactive material.

According to a specific implementations of the present invention, fluoropolymer with comprise at least a noble metal with choose any one kind of them or the weight ratio of the catalyst material of variety carrier material greater than 0.1, this ratio is preferably in 0.2 to 0.6 scope.

According to a specific execution mode of the present invention, the thickness of said catalyst layer be 1 to 1000 μ m, especially be 5 to 500 μ m, be preferably 10 to 300 μ m.This value is represented mean value, and it can be measured through using the layer cross sectional image that can use scanning electron microscopy (SEM) to obtain.

According to a specific implementations of the present invention, the content of the noble metal of said catalyst layer is 0.1 to 10.0mg/cm ², be preferably 0.3 to 6.0mg/cm ²And be preferably 1 especially to 4.0mg/cm ²These values can be measured through the elementary analysis flat sample.

Ionomer material according to the present invention is present on the catalyst layer at negative electrode place with definite ratio with respect to the content of catalyst material.Therefore, the weight ratio of preferred ionomer material and catalyst is 100:1 to 1:100, most preferably is 10:1 to 1:10.Certain preferred ratio is 1:8 to 1:3.If desired, then this tittle and ratio also are applicable to the catalyst layer in anode.

Catalyst layer is not self-supporting usually, but is applied to usually on gas diffusion layers and/or the film.In this connection, the part of catalyst layer can for example be diffused in gas diffusion layers and/or the film, causes forming transition zone.This also can be so that catalyst layer be regarded as the part of gas diffusion layers.The thickness of catalyst layer is produced by the thickness of measuring the layer that has applied catalyst layer on its of gas diffusion layers for example or film, and this measurement provides the summation of summation, for example gas diffusion layers and the catalyst layer of catalyst layer and equivalent layer.Said catalyst preferable configuration gradient, promptly the content of noble metal raises along the direction of film, and the performance of the content of hydrophobic material is opposite.

For out of Memory about membrane electrode assembly, reference technique document, especially patent application WO 01/18894A2, DE 19509748, DE 19509749, WO 00/26982, WO 92/15121 and DE 19757492.Contained in the above referred-to references about membrane electrode assembly structure and production and also be the part of this specification with the disclosure of electrode, gas diffusion layers and the catalyst selected.

Sealing ring

The sealing ring that in scope according to the method for the invention, uses or produce in step separately, produce and use or the circumferential edges at gas diffusion layers on the optional raised brim of the circumference of bipolar plates on directly produce.

In this connection, requisite is that sealing ring in formed structure inner boundary zone is inwardly overlapping and therefore with gas diffusion layers or to be provided with the external boundary zone of gas diffusion layers of catalyst layer overlapping.

Overlapping through this, gas diffusion layers is fixed in the bipolar plates, make and can save other arrangement or fixed frame.In addition, the borderline region of gas diffusion layers no longer necessarily is scattered with the borderline region that encapsulant or encapsulant no longer must the sweep gas body diffused layer and realizes sealing function.

In addition, advantageously,, for example then make in compression step subsequently gas diffusion layers and/or film/electrolyte matrix can not be destroyed if sealing ring has enough mechanical stabilities and/or integrality.For this purpose, can so-called hard stop function be integrated in the sealing ring in an advantageous manner.When sealing ring when producing on the bipolar plates rather than on raised brim, preferred especially this execution mode.

The production of sealing ring can be carried out in independent step or sealing ring directly produces towards bipolar plates on the circumferential edges of gas diffusion layers.The formation of sealing ring can be carried out through all known methods, preferably applies thermoplastic elastomer (TPE) or crosslinkable rubber or these compounds is applied and/or make its crosslinked carrying out through printing process through spraying.

Preferably, sealing ring according to the present invention by can hot worked melting polymer or rubber form.

Among rubber, preferred silicon rubber (Q), ethylene-propylene-diene rubber (EPDM), ethylene-propylene rubber (EPM), butyl rubber (MR), butadiene rubber (BR), SBR styrene butadiene rubbers (SBR), styrene isoprene rubber (SIR), isoprene-butadiene rubber (IBR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), neoprene (CR), ACM (ACM) and/or derive from the partially hydrogenated rubber of butadiene rubber (BR), butadiene-styrene rubber (SBR), isoprene-butadiene rubber (IBR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), Oppanol (PIB), fluorubber (FPM), fluorosioloxane rubber (MFQ, FVMQ).

In addition, as encapsulant, this fluoropolymer is preferably and gathers (tetrafluoroethene-be total to-hexafluoropropylene) FEP, Kynoar PVDF, perfluoroalkoxy PFA and gather (tetrafluoroethene-be total to-perfluor (methyl vinyl ether) MFA with fluoropolymer.These polymers can be in many ways, for example, trade names and

The following commercially available.

Except above-mentioned material, also can use encapsulant based on polyimides.This type also comprises based on the polymer of polyimides and except imide group, also contains amide groups (polyamidoimide), ester group (polyesterimide) and ether (PEI) polymer as backbone component.

Preferred polyimides has the repetitive of general formula (VI):

Wherein functional group A r has above-mentioned implication and the R of functional group representative and has the alkyl group or the two covalency aromatics or the heteroaromatic group of 1 to 40 carbon atom.Preferably; The R of functional group representative is derived from benzene, naphthalene, biphenyl, diphenyl ether, benzophenone, diphenyl methane, diphenyl dimethylmethane, benzophenone, diphenyl sulphone (DPS), quinoline, pyridine, bipyridine, anthracene, thiadiazoles and two luxuriant and rich with fragrance covalency aromatics or heteroaromatic group, and they are chosen wantonly and also can be substituted.Mark n points out the repetitive of the part of representation polymer.

Such polymers may be trade names

and

down from DuPont (DuPont) and a commercially available product name

down from GE? Plastics (GE Plastics) and a commercially available product name

down from Ube? Industries (Ube Kosan Company) commercially available.

Combination with above-mentioned material of soft/rigid matter combination also is suitable as encapsulant, especially with integrated above-mentioned hard stop function (hard stop funtion) time.

The Xiao A hardness of preferred especially encapsulant is 5 to 85, especially be 25 to 80.Shore hardness is measured according to DIN 53505.In addition, advantageously, the permanent deformation of encapsulant is less than 50%.Permanent deformation is measured according to DIN ISO 815.

The thickness of sealing ring is influenced by several factors.How high main factor for being chosen as at the height in the borderline region of bipolar plates.The thickness of the sealing ring that usually, produces or use is 5 μ m to 5000 μ m, be preferably 10 μ m to 1000 μ m and especially be 25 μ m to 150 μ m.Specifically, under the situation of the bipolar plates of not protruding borderline region, thickness also can be higher.

Sealing ring also can be used several layers of structure.In this embodiment, use suitable polymers, the especially very suitable fluoropolymer that enough connects of setting up that different layers is connected to each other.Suitable fluoropolymer is known by those of ordinary skills.These fluoropolymers especially comprise polytetrafluoroethylene (PTFE) and gather (tetrafluoroethene-be total to-hexafluoropropylene) (FEP).On above-mentioned sealant, exist by fluoropolymer process the layer thickness be generally at least 0.5 μ m, especially be at least 2.5 μ m.If the fluoropolymer that use to expand, then the thickness of this layer can be for 5 to 250 μ m, be preferably 10 to 150 μ m.

Above-mentioned sealing ring or encapsulant make them that gas diffusion layers is fixed in the recess that bipolar plates is shaped.For this purpose, advantageously, the external boundary of sealing ring and gas diffusion layers zone circumference is overlapping.Based on the outermost edge of gas diffusion layers, the borderline region of sealing ring and gas diffusion layers overlapping is preferably 0.1 to 5mm, is preferably 0.1 to 3mm.Bigger overlapping be possible, but cause catalytically active surface to lose strongly.For this reason, overlapping degree must be with crucial mode balance so that can not cover most catalytically active surface.

Though advantageously the borderline region circumference of sealing ring and gas diffusion layers is overlapping, also can especially there be the overlapping discontinuity of the borderline region of circumferential sealing edge and gas diffusion layers with respect to the active catalytic surface.In this connection, guarantee that through sealing ring the fixed function of gas diffusion layers is absolutely necessary.

Bipolar plates

Bipolar plates of using within the scope of the invention or dividing plate are typically provided with processing medium passage (flow field channel) to allow the distinctive reactant of distribution fuel cell and other fluid such as cooling fluid.

Said bipolar plates is formed by electric conducting material usually; These electric conducting materials can be metal or nonmetallic materials.

If bipolar plates is constructed by nonmetallic materials, then preferred so-called composite material.The composite material compound that the host material that is provided with conductive filler is processed of serving as reasons.Polymeric material, especially organic polymer preferably are suitable as host material.The operating temperature that depends on fuel cell also possibly need high-performance polymer, especially heat stabilized polymer.Depend on the use field, use the long-term work temperature at least 80 ℃, be preferably at least 120 ℃, be preferably at least 180 ℃ polymer especially.

Especially preferably use thermoplastic polymer; Especially polypropylene (PP), Kynoar (PVDF), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS) and liquid-crystalline polymer (LCP); Also possibly use these polymer, promptly mix with other polymer and typical additive respectively as composition.Except said thermoplastic polymer, also preferred thermoset plastics and resin.Particularly use phenol resin (PF), melmac (MF), polyester (UP) and epoxy resin (EP).

To allow that the particle matter that is evenly distributed in as far as possible in the matrix is as conductive filler.Preferably, these fillers have the volume conduction rate of 10mS/cm at least.Especially preferably use carbon, graphite and carbon black.These fillers also can be processed to realize the better wetability with host material.Granularity is not influenced by any specific limited, but must allow and produce this type bipolar plates.Except above-mentioned conductive filler, even can other additive that improvement applies performance be added in the host material.If especially can not guarantee to have in addition mechanical load, then also possibly use fibre reinforced materials.

Produce this type bipolar plates preferably through suitable manufacturing process, especially carry out through injection molding technology and injection embossing and embossing technology.

Except the pipe of processing medium, bipolar plates can also have other pipe or opening or hole, and for example cooling agent or reacting gas can be through said pipe or opening or hole supply and dischargings.

The thickness of nonmetal bipolar plates is preferably 0.3 to 10mm, especially be 0.5 to 5mm and be preferably 0.5 especially to 2mm.The conductivity of nonmetal bipolar plates is more than or equal to 25S/cm.

If bipolar plates is constructed by metal material, then has the effective global design of cost more.The structure of this metalloid bipolar plates is not influenced by any substantial limit.

Preferred corrosion-resistant and acidproof steel is as metal material, especially based on V2A and V4A steel those and process by nickel-base alloy those.The preferred in addition tabular or metal that applies, especially have those metals of the corrosion-resistant surface of processing by noble metal, nickel, ruthenium, niobium, tantalum, chromium, carbon and be coated with ceramic material, the metal of the coating especially processed by complex nitride, carbide, silicide and the oxide of CrN, TiN, TiAlN, metal and transition metal.In addition, metal double polar plates can have following coating in addition, and it reduces the surface resistivity of the contact of gas diffusion layers/bipolar plates on the one hand, otherwise just strengthens chemistry and/or the physical resistance of bipolar plates to the medium of existence in fuel cell or formation.

The structure of metal double polar plates can be undertaken by separate board, and therefore it can form the hole that the cooling agent that must supply and discharge or reaction medium are used with simple mode.The connection of separate board can be carried out like welding or seam through the material associated methods.If desired, then hole for example relative to each other seals through other inner coating in addition, thereby can avoid seepage.

If structure does not contain the fuel cell system of cooling layer or several independent batteries of fuel cell pack are without any need for cooling in this type systematic, then bipolar plates in battery pile or independent bipolar plates also can be from only having a metal or nonmetallic separate board manufacturing.

The structure of suitable metal double polar plates and production are described in detail in DE-A-10250991, WO2004/036677, WO 2004/105164, WO 2005/081614, WO 2005/096421 and WO 2006/037661.The assembly and the production method of statement also are the parts of the present invention and this specification therein.

The thickness of metal double polar plates is preferably 0.03 to 1mm, especially be 0.05 to 5mm and be preferably 0.05 especially to 0.15mm.

The bipolar plates of using within the scope of the invention can lobed borderline region, makes the zone of the bipolar plates that contains flow field channel form recess.Make the maximum height with respect to the bipolar plates zone with processing medium passage, the accurate height of borderline region adapts to the thickness of gas diffusion layers or has the thickness of the gas diffusion layers of catalyst layer.If gas diffusion layers or the gas diffusion layers with catalyst layer do not receive the influence of any further compression during compression step subsequently, then the height of the borderline region of bipolar plates is corresponding to gas diffusion layers or have the thickness of the gas diffusion layers of catalyst layer.

If the thickness of gas diffusion layers or the thickness with gas diffusion layers of catalyst layer are higher than the height of the borderline region relative with the maximum height in the bipolar plates zone with processing medium pipe, the compression that then during compression step subsequently, produces gas diffusion layers.The degree of compression is determined so that encapsulant plays the effect of hard stop by the thickness and the formability of encapsulant.This execution mode is using soft or advantageous particularly during the polymer dielectric film that can be shaped easily, because this can be avoided film to damage.

The height that has been found that the height in the zone of plan boundary advantageously or pass the frame shape assembly makes gas diffusion layers or the gas diffusion layers experience with catalyst layer compare at least 3% compression with original thickness.Particularly preferably, the above-mentioned height of selecting borderline region is so that compression at least 5%.Will be greater than 50%, especially be chosen as the upper limit greater than 30% compression, possibly also surpass the compression that realizes through other parameters of choice.

The compression of assembly is carried out through the effect of pressure and temperature, so that assembly forms tight connection each other.In general, this be compressed in 10 to 300 ℃, especially under 20 ℃ to 200 ℃ the temperature and, especially carry out under the pressure of 3 to 300 crust at 1 to 1000 crust.Above-mentioned compression also can take place during the production battery pile and/or in the starting fluid battery pile time.

After this, electrochemical cell, especially fuel cell is available and can use with independent battery.In order to produce fuel cell pack, use potential independent cell arrangement to be battery pile fuel cell.In addition, the production of fuel cell pack can be carried out through using the parts of partly processing according to the present invention, and these parts that have required film in advance can be provided.In this connection, film is previous to be obtained as for example scroll, and can be cut individually to be fit to divide other bipolar plate design, wherein minimum level ground materials used.Need not increase operation framework.Normally known by fuel cell with independent battery production fuel cell pack.

Provide according to electrode of the present invention and membrane electrode assembly, described in following examples, contain fluorine and contain the polymer that the imino group of phosphoric acid is adsorbed in permission simultaneously.When with it when being coated in the ionomer on the electrode, obtain significantly higher hydrogen reduction electric current.Therefore, show that the overpotential of electrode reduces, and fuel cell voltage raises.

Under the situation that does not receive the restriction of specific scientific model, this effect can be explained through the fact that in polymer architecture, comprises fluorine and increase the oxygen solubility of himself.Under situation of the present invention, add or the method that applies this type fluoropolymer is to improve the effective means of fuel cell performance to negative electrode obviously.

Embodiment

The polymer manufacture program

Polymer 1: polybenzimidazoles (PBI)

Use derives from the base polymer that (2,2'-metaphenylene-5,5'-bisbenzimidazole) conduct is used for comparison that gathers of BASF Fuel Cell GmbH (the effective company of BASF fuel cell share).

Polymer 2: fluoropolymer 1

Will be with 4 shown in the formula 1,4'-(hexafluoroisopropyli,ene) dibenzoic acid is used as dicarboxylic acids, and will be with 3 shown in the formula 2, and 3'-diaminobenzidine four hydrochlorides are as the monomer that contains amino group.

Under blanket of nitrogen, use polyphosphoric acid (117% phosphoric acid) as reaction dissolvent, be reflected at 170 ℃ and took place 12 hours down, and further took place 90 hours down at 220 ℃.It is very sticking that reactant mixture becomes.

With in the big water gaging of mixture impouring and through filtering the collecting precipitation thing.Sediment is put in the boiling water and it was refluxed 24 hours, to remove the polyphosphoric acid that desolvates.Infrared spectrum is presented at 1633cm ^-1Under imino group (C=N) absorb and at 3400 ~ 2600cm ^-1Under imidazole ring absorb, this has confirmed molecular structure 1.

Molecular weight uses PEO to measure as interior mark material through GPC (gel permeation chromatography).Based on the result who measures, number-average molecular weight M _nBe 6.0 * 10 ⁴, and weight average molecular weight M _wBe 31 * 10 ⁴

This polymer is dissolvable in water among organic solvent such as dimethylacetylamide and the NMP (N-methyl pyrrolidone).

The polymer solution of 5 weight % is dispersed on the glass plate, and, finally obtains the brown toughness film through heating except that after desolvating.Verified through in 85% phosphoric acid, soaking 1 hour down at 40 ℃, film can be transformed into the gel film that contains 75 ~ 80 weight % phosphoric acid.

Polymer 3: fluoropolymer 2

Will be with 4 shown in the formula 3,4'-oxygen base two (benzoic acid) is used as dicarboxylic acids, and will be with 2 shown in the formula 4, and two (3-amino-4-hydroxy phenyl) the HFC-236fa dihydrochlorides of 2-are as the monomer of amido-containing group.

Under blanket of nitrogen, use polyphosphoric acid (117% phosphoric acid) as reaction dissolvent, be reflected at 170 ℃ and took place 4 hours down, and further took place 34 hours down at 203 ℃.It is very sticking that reactant mixture becomes.

With in the big water gaging of mixture impouring and through filtering the collecting precipitation thing.Sediment is put in the boiling water and it was refluxed 24 hours, to remove the polyphosphoric acid that desolvates.Infrared spectrum is presented at 1599cm ^-1Under imino group (C=N) absorb, at 3400 ~ 2600cm ^-1Under imidazole ring absorb and at 1246cm ^-1Under C-O-C absorb, this has confirmed molecular structure 2.

Molecular weight uses PEO to measure as interior mark material through GPC (gel permeation chromatography).Based on the result who measures, number-average molecular weight M _nBe 0.57 * 10 ⁴, and weight average molecular weight M _wBe 1.7 * 10 ⁴

This polymer is dissolvable in water among organic solvent such as acetamide and the NMP (N-methyl pyrrolidone).

The polymer solution of 5 weight % is dispersed on the glass plate, and, finally obtains the brown stiffness films through heating except that after desolvating.Verified through in 85% phosphoric acid, soaking 1 hour down at 40 ℃, film can be transformed into the gel film that contains 50 ~ 60 weight % phosphoric acid.

Polymer 4: fluoropolymer 3

To be used as dicarboxylic acids with the decanedioic acid shown in the formula 5, and will be with 2 shown in the formula 6, two (3-amino-4-hydroxy phenyl) the HFC-236fa dihydrochlorides of 2-are as the monomer of amido-containing group.

Under blanket of nitrogen, use polyphosphoric acid (117% phosphoric acid) as reaction dissolvent, be reflected at 130 ℃ and took place 1 hour down, and further took place 24 hours down at 180 ℃.It is very sticking that reactant mixture becomes.

With in the big water gaging of mixture impouring and through filtering the collecting precipitation thing.Sediment is put in the boiling water and it was refluxed 24 hours, to remove the polyphosphoric acid that desolvates.Infrared spectrum is presented at 1629cm ^-1Under imino group (C=N) absorb and at 3400 ~ 2600cm ^-1Under imidazole ring absorb, this has confirmed molecular structure 3.

The polymer solution of 5 weight % is dispersed on the glass plate, and, finally obtains the brown stiffness films through heating except that after desolvating.Verified through in 85% phosphoric acid, soaking 1 hour down at 40 ℃, film can be transformed into the gel film that contains 70 ~ 75 weight % phosphoric acid.

Electrochemical measurement

A) electrode preparation

Active for the electrochemical oxygen reduction of measuring the electrode that contains above-mentioned polymer, carry out half-cell and measure.As reference and counterelectrode, use to have 0.5mg/cm ²The porous Pt-carbon electrode of Pt content.As electrolyte, use the polybenzimidazole membrane (80 weight % use 85% phosphoric acid) of doping phosphoric acid.Work electrode passes through Pt mesh electrode (1cm ²Geometric area) be dipped in the solution of 3 ~ 5 weight % of phase emergencing copolymer in dimethylacetamide solvent, evaporating solvent prepares subsequently.The resulting polymers coating is quantitative in table 1.

Table 1

Table 1: the polymer coating weight on work electrode

B) electrochemical measurement

Electrochemical measurement is through suppressing anti-/ reference electrode, loading the PBI film of acid and the work electrode completion with gas access/outlet between two graphite cakes.Measurement is carried out under 140 ℃.Instead/reference electrode is with the continuous purge of hydrogen.Work electrode comes continuous purge with the 0.4L/min pure oxygen or with air (high flow rate is to guarantee that gas effciency is near zero).The activity of electrode under 0.7V and 140 ℃ (ambient pressure) is summarized in the table 2.

Table 2

Table 2: derive from the hydrogen reduction active (it should be noted that reduction current is designated as positive current in this table) of electrode of the present invention.

Claims

1. membrane electrode assembly, it comprises:

(i) at least two electrochemical activity electrodes,

(iv) said catalyst layer comprises at least a ionomer material,

It is characterized in that the said catalyst layer that contacts with negative electrode at least comprises the polymer as the repetitive that comprises general formula (I) of ionomer material:

Wherein (a)

X is identical or different and represent N, O, S, and

And

N is 0.1 to 99.9 mole of %,

Or (b)

X is identical or different and represent N, O, S, and

And

Z ³It is identical or different and represent N, O, S,

And

N is 0.1 to 99.9 mole of %.

2. membrane electrode assembly according to claim 1, wherein, two supply options (a) or (b) in, n is 40 to 60 moles of %, is preferably 50 moles of %, so that quantitative (ration) between two kinds of secondary units of said repetitive is quite or equal.

3. membrane electrode assembly according to claim 1, wherein, two supply options (a) or (b) in, X represents N or O.

4. membrane electrode assembly according to claim 1, wherein, in supplying option (b), X represents O.

5. membrane electrode assembly according to claim 1 is wherein at Z ¹And/or Z ²In alkyl represent short chain divalent alkyl group independently of one another with 1 to 6 carbon atom, be preferably methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane.

6. membrane electrode assembly according to claim 1 is wherein at Z ¹And/or Z ²In alkyl represent short chain divalent alkyl group independently of one another with 1 to 6 carbon atom; Be preferably methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane, wherein at least one carbon atom be perfluor or at least one carbon atom by at least one (CF ₃)-group, most preferably by two (CF ₃)-group replaces with formation-C (CF ₃) ₂-group.

7. membrane electrode assembly according to claim 1 is wherein at Z ¹And/or Z ²In aromatic group represent divalent aromatic radical independently of one another with 5 to 6 carbon atoms; The hetero-atom that wherein one or more carbon atoms can be selected from N, O or S replaces, wherein at least one carbon atom be perfluor or at least one carbon atom by at least one (CF ₃)-group replaces; Or having the alkyl group of 2 to 6 carbon atoms, it is by at least one (CF ₃)-group, most preferably by two (CF ₃)-group replaces with formation-C (CF ₃) ₂-group or by end-C (CF ₃) ₃Group replaces.

8. membrane electrode assembly according to claim 1, wherein, in supplying option (b), R ¹Representative has the divalent alkyl group of 1 to 10 carbon atom independently of one another, is preferably methyl, ethyl, n-pro-pyl or isopropyl and normal-butyl, isobutyl group or the tert-butyl group, pentane, isopentane or uncle's pentane, n-hexane, isohexane or uncle's hexane.

9. membrane electrode assembly according to claim 1, wherein, in supplying option (b), R ¹Representative has the divalent aromatic radical of 5 to 6 carbon atoms independently of one another, and the hetero-atom that wherein one or more carbon atoms can be selected from N, O or S replaces.

10. membrane electrode assembly according to claim 1, wherein two covalency aromatic groups or two covalency heteroaromatic group Ar ¹, Ar ², Ar ⁵, Ar ⁶Representative has monocycle, dicyclo or the condensing or non-condensed aromatics or heteroaromatic ring system of encircling of 5 to 20 carbon atoms more independently of one another, and wherein one or more carbon atoms can be replaced by N, O, S, and said two covalency aromatic groups or two covalency heteroaromatic group Ar ¹, Ar ², Ar ⁵, Ar ⁶Can be replaced by other group.

11. membrane electrode assembly according to claim 1, the said polymer that wherein comprises the repetitive of said general formula (I) has the repetitive of at least 10 said general formulas (I), the more preferably repetitive of at least 50 said general formulas (I).

12. membrane electrode assembly according to claim 1, the said polymer that wherein comprises the repetitive of said general formula (I) has the weight average molecular weight M greater than 10000 _w(through gel permeation chromatography).

13. membrane electrode assembly according to claim 1, the said polymer that wherein comprises the repetitive of said general formula (I) has the number-average molecular weight M greater than 5000 _n

14. membrane electrode assembly according to claim 1, the said polymer solubility in DMAc under 25 ℃ temperature that wherein comprises the repetitive of said general formula (I) is at least 0.5 weight %.

15. membrane electrode assembly according to claim 1, wherein the weight ratio of ionomer material and catalyst material is 100:1 to 1:100, is preferably 10:1 to 1:10, most preferably is 1:8 to 1:3 in said catalyst layer.

16. membrane electrode assembly according to claim 1, wherein said polymer dielectric film or the electrolyte matrix proton conductivity under 120 ℃ temperature for 1mS/cm at least, be preferably at least 2mS/cm, especially be 5mS/cm at least.

17. the polymer of a repetitive that comprises general formula (I) is as the ionomer material, preferably as the purposes of the ionomer material in negative electrode,

Wherein (a)

X is identical or different and represent N, O, S, and

And

N is 0.1 to 99.9 mole of %,

Or (b)

X is identical or different and represent N, O, S, and

And

Z ³It is identical or different and represent N, O, S,

And

N is 0.1 to 99.9 mole of %.

18. a fuel cell, it comprises at least a according to the described membrane electrode assembly of claim 1 to 16.