EP1955400A1 - Ensembles membrane-electrodes ameliores et piles a combustible a duree de vie plus longue - Google Patents

Ensembles membrane-electrodes ameliores et piles a combustible a duree de vie plus longue

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Publication number
EP1955400A1
EP1955400A1 EP06806596A EP06806596A EP1955400A1 EP 1955400 A1 EP1955400 A1 EP 1955400A1 EP 06806596 A EP06806596 A EP 06806596A EP 06806596 A EP06806596 A EP 06806596A EP 1955400 A1 EP1955400 A1 EP 1955400A1
Authority
EP
European Patent Office
Prior art keywords
group
polymer
acid
azobis
aryl
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP06806596A
Other languages
German (de)
English (en)
Inventor
Oemer Uensal
Jörg BELACK
Vesselin Sinigersky
Ivan Schopov
Hhristo Bratschkov
Stoicho Schenkov
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF Fuel Cell Research GmbH
Original Assignee
BASF Fuel Cell GmbH
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Filing date
Publication date
Application filed by BASF Fuel Cell GmbH filed Critical BASF Fuel Cell GmbH
Publication of EP1955400A1 publication Critical patent/EP1955400A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F130/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal
    • C08F130/02—Homopolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal containing phosphorus
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F230/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal
    • C08F230/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal containing phosphorus
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F30/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal
    • C08F30/02—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and containing phosphorus, selenium, tellurium or a metal containing phosphorus
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/20—Manufacture of shaped structures of ion-exchange resins
    • C08J5/22—Films, membranes or diaphragms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/102—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer
    • H01M8/1023—Polymeric electrolyte materials characterised by the chemical structure of the main chain of the ion-conducting polymer having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1039—Polymeric electrolyte materials halogenated, e.g. sulfonated polyvinylidene fluorides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1041—Polymer electrolyte composites, mixtures or blends
    • H01M8/1046—Mixtures of at least one polymer and at least one additive
    • H01M8/1048—Ion-conducting additives, e.g. ion-conducting particles, heteropolyacids, metal phosphate or polybenzimidazole with phosphoric acid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1069—Polymeric electrolyte materials characterised by the manufacturing processes
    • H01M8/1072—Polymeric electrolyte materials characterised by the manufacturing processes by chemical reactions, e.g. insitu polymerisation or insitu crosslinking
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M8/00—Fuel cells; Manufacture thereof
    • H01M8/10—Fuel cells with solid electrolytes
    • H01M8/1016—Fuel cells with solid electrolytes characterised by the electrolyte material
    • H01M8/1018—Polymeric electrolyte materials
    • H01M8/1069—Polymeric electrolyte materials characterised by the manufacturing processes
    • H01M8/1081—Polymeric electrolyte materials characterised by the manufacturing processes starting from solutions, dispersions or slurries exclusively of polymers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to vinyl phosphonic acid polymers and vinyl sulfonic acid polymers of high molecular weight, which can be widely used because of their excellent chemical and physical properties and are particularly suitable for polymer electrolyte membranes (PEM) in so-called PEM fuel cells.
  • PEM polymer electrolyte membranes
  • a fuel cell usually contains an electrolyte and two electrodes separated by the electrolyte.
  • one of the two electrodes is supplied with a fuel such as hydrogen gas or a methanol-water mixture and the other electrode with an oxidant such as oxygen gas or air, thereby directly converting chemical energy from the fuel oxidation into electrical energy.
  • an oxidant such as oxygen gas or air
  • the electrolyte is hydrogen ions, i. Protons, but not reactive
  • Fuels such as the hydrogen gas or methanol and the oxygen gas permeable are provided.
  • the electrolyte used for the fuel cell are solids such as polymer electrolyte membranes or liquids such as phosphoric acid. Recently, polymer electrolyte membranes have been used as electrolytes for the fuel cell.
  • the first category includes cation-exchange membranes consisting of a polymer backbone containing covalently bound acid groups.
  • sulfonic acid-modified polymers are used as proton-conducting membranes.
  • proton-conducting membranes are predominantly perfluorinated polymers application.
  • Nafion TM by DuPont de Nemours, Willmington USA.
  • For the proton conduction is a relatively high Required water content in the membrane, which is typically at 4 - 20 molecules of water per sulfonic acid group.
  • the necessary water content, but also the stability of the polymer in combination with acidic water and the reaction gases hydrogen and oxygen, the operating temperature of the PEM fuel cell stacks usually limited to 80 - 100 0 C. Under pressure, the
  • Operating temperatures can be increased to> 120 0 C. Otherwise, higher operating temperatures can not be realized without a power loss of the fuel cell.
  • a disadvantage is that the acid, usually phosphoric acid or polyphosphoric acid, is not permanently bound to the basic polymer and by water, especially at operating temperatures below 100 ° C, z. B. when starting or stopping the cell, can be washed out. This can lead to a steady loss of conductivity and cell performance, which reduces the life of the fuel cell.
  • WO 03/075389 it is proposed in WO 03/075389 to use a polymer membrane which is obtained by polymerization of vinyl-containing phosphonic acid in the presence of a preferably basic polymer.
  • the degree of polymerization of the polyvinylphosphonic acid is preferably greater than 100.
  • the membrane should be particularly suitable for the production of fuel cells with the following properties:
  • the fuel cells should last as long as possible. • The fuel cells should be as wide as possible
  • Operating temperature range (above and below 100 ° C), in particular above 100 ° C, can be used.
  • the fuel cells should have as high a quiescent voltage as possible and as little gas penetration as possible (gas cross-over). Furthermore, they should be able to be operated at the lowest possible stoichiometry. • The fuel cells should survive at temperatures above 100 ° C as possible without additional fuel gas moistening.
  • the fuel cells should be able to withstand permanent or changing pressure differences between anode and cathode in the best possible way.
  • the fuel cells should be robust against different operating conditions (T, P, geometry, etc.) to the general
  • the fuel cells should have improved temperature and corrosion resistance and a comparatively low gas permeability, especially at high temperatures. A decrease in mechanical stability and structural integrity, especially at high temperatures, should be avoided as much as possible.
  • the fuel cells should be able to be produced in a simple manner, on a large scale and cost-effectively.
  • the present invention accordingly provides a method for
  • a high molecular weight polymer comprising free-radically polymerizing a composition comprising, by total weight, at least 80.0% by weight of ethylenically unsaturated compounds, said composition containing at least one monomer comprising phosphonic acid groups and / or sulfonic acid groups.
  • the present invention relates to a polymer having a weight average of the degree of polymerization greater than 300, which is obtained by the process according to the invention and a membrane-electrode assembly comprising two electrochemically active electrodes (anode and cathode) passing through a polymer electrolyte membrane be separated, wherein the polymer electrolyte membrane comprises at least one inventive polymer.
  • the polymer of the invention is characterized by a comparatively high molecular weight. Its weight average degree of polymerization is greater than 300, preferably greater than 500, advantageously greater than 1000, in particular greater than 1500. It can be determined in a manner known per se, wherein the static light scattering has proven particularly useful in this context. Alternatively, the degree of polymerization can also be determined by GPC methods.
  • the polymer of the invention preferably has a broad molecular weight distribution, its polydispersity M w / M n is favorably in the range of 1 to 20, particularly preferably in the range of 3 to 10.
  • the polymer according to the invention preferably has an inherent
  • Viscosity (Staudinger Index) greater than 1, 0 dl / g, advantageously greater than 5.0 dl / g, in particular greater than 10.0 dl / g, each measured as 0.4 wt .-% solution at 25 0 C.
  • the preparation of the polymer according to the invention is preferably carried out by free-radical polymerization of a composition which, based on its total weight, is at least 80.0% by weight, preferably at least 85.0% by weight, particularly preferably at least 90.0% by weight, in particular at least 95.0% by weight, of ethylenically unsaturated compounds and containing at least one monomer containing phosphonic acid groups and / or sulphonic acid groups.
  • Monomers comprising phosphonic acid groups are known in the art. These are compounds which have at least one carbon-carbon double bond and at least one phosphonic acid group.
  • the two carbon atoms that form the carbon-carbon double bond have at least two, preferably three, bonds to groups that result in little steric hindrance of the double bond.
  • groups include, among others, hydrogen atoms and halogen atoms, especially fluorine atoms. In the context of the present invention, this results
  • Phosphonklare phenomenon comprising polymer from the polymerization, which is obtained by polymerization of the phosphonic acid comprising monomers alone or with other monomers and / or crosslinkers.
  • the monomer comprising phosphonic acid groups may be one, two, three or more
  • the monomer comprising phosphonic acid groups may contain one, two, three or more phosphonic acid groups.
  • the monomer comprising phosphonic acid groups contains 2 to 20, preferably 2 to 10, carbon atoms.
  • the monomer comprising phosphonic acid groups are preferably compounds of the formula
  • R is a bond, a divalent C1-C15 alkylene group, divalent C1-C15
  • Alkyleneoxy for example, ethyleneoxy group, or a divalent C5-C20-aryl or heteroaryl group, wherein the above groups in turn may be substituted with halogen, -OH, COOZ, -CN, NZ 2 , Z are independently hydrogen, C1-C15-alkyl group , C1-C15 alkoxy group, for example ethyleneoxy group, or C5-C20-aryl or heteroaryl group, where the above radicals may themselves be substituted by halogen, -OH, -CN, and x is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, y is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 and / or the formula
  • R is a bond, a C1-C15 double-alkylene group, C1-C15 double-bonded
  • Alkyleneoxy for example, ethyleneoxy group, or a divalent C5-C20-aryl or heteroaryl group, wherein the above groups in turn may be substituted with halogen, -OH, COOZ, -CN, NZ 2 , Z are independently hydrogen, C1-C15-alkyl group C 1 -C 15 alkoxy group, for example ethyleneoxy group or C 5 -C 20 -aryl or
  • Heteroaryl group where the above radicals may in turn be substituted by halogen, -OH, -CN, and x is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 and / or the formula
  • A is a group of the formulas COOR 2 , CN, CONR 2 2 , OR 2 and / or R 2 , R 2 is hydrogen, a C 1 -C 15 -alkyl group, C 1 -C -alkoxy group, for example ethyleneoxy group or C 5 -C 20 -aryl or heteroaryl group in which the above radicals may themselves be substituted by halogen, -OH, COOZ, -CN, NZ 2
  • R is a bond, a C1-C15 divalent alkylene group, C1-C15 divalent alkyleneoxy group, for example ethyleneoxy group or C5-C20 dangylated aryl or heteroaryl group, the above radicals themselves being halogen, -OH, COOZ, -CN, NZ may be substituted 2, Z are independently hydrogen, C1-C15 alkyl group, C1-C15
  • Alkoxy group for example ethyleneoxy group or C5-C20-aryl or heteroaryl group, where the above radicals may themselves be substituted by halogen, -OH, -CN, and x is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 means.
  • the monomers comprising preferred phosphonic acid groups are, inter alia, alkenes having phosphonic acid groups, such as ethenephosphonic acid, propenephosphonic acid, butenephosphonic acid; Acrylic acid and / or methacrylic acid compounds which have phosphonic acid groups, for example 2-phosphonomethylacrylic acid, 2-phosphonomethylmethacrylic acid,
  • vinylphosphonic acid ethenphosphonic acid
  • ethenphosphonic acid such as is obtainable, for example, from Aldrich or Clariant GmbH
  • a preferred vinylphosphonic acid has a
  • the monomers comprising phosphonic acid groups can furthermore also be used in the form of derivatives which can subsequently be converted into the acid, the conversion to the acid also taking place in the polymerized state.
  • derivatives include, in particular, the salts, the esters, the amides and the halides of the monomers comprising phosphonic acid groups.
  • composition to be used according to the invention comprises, based on it
  • Total weight preferably at least 20 wt .-%, in particular at least 30 wt .-% and particularly preferably at least 50 wt .-%, comprising phosphonic acid monomers.
  • ionomeric compositions containing sulfonic acid groups can be used to prepare the phosphonic acid group-containing polymers and / or phosphonic acid groups. The weight ratio of monomers comprising sulfonic acid groups
  • Phosphonic acid monomers comprising preferably in the range of 100: 1 to 1: 100, preferably in the range of 10: 1 to 1: 10 and particularly preferably in the range of 2: 1 to 1: 2.
  • Monomers comprising sulfonic acid groups are known in the art. These are compounds which have at least one carbon-carbon double bond and at least one sulfonic acid group. Preferably, the two carbon atoms that form the carbon-carbon double bond have at least two, preferably three, bonds to groups that result in little steric hindrance of the double bond. These groups include, among others, hydrogen atoms and halogen atoms, especially fluorine atoms.
  • the polymer comprising sulfonic acid groups results from the polymerization product which is obtained by polymerization of the monomer comprising sulfonic acid groups alone or with further monomers and / or crosslinkers.
  • the monomer comprising sulfonic acid groups may comprise one, two, three or more carbon-carbon double bonds. Further, the monomer comprising sulfonic acid groups may contain one, two, three or more sulfonic acid groups.
  • the monomer comprising sulfonic acid groups contains 2 to 20, preferably 2 to 10, carbon atoms.
  • the monomer comprising sulfonic acid groups are preferably compounds of the formula
  • R is a bond, a divalent C1-C15 alkylene group, divalent C1-C15
  • Alkylenoxy may in turn be substituted by halogen, -OH, COOZ 1 -CN, NZ 2 , Z is independently of one another hydrogen, C1-C15-alkyl group, C1-C15-alkoxy group, for example ethyleneoxy group or C5-C20-aryl or heteroaryl group, where the above radicals may themselves be substituted by halogen, -OH, -CN, and x is an integer Number 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 means y is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10
  • R is a bond, a C1-C15 double-alkylene group, C1-C15 double-bonded
  • Alkylenoxy may in turn be substituted by halogen, -OH, COOZ, -CN, NZ 2 ,
  • Z is independently hydrogen, C1-C15-alkyl group, C1-C15-alkoxy group, for example ethyleneoxy group or C5-C20-aryl or
  • Heteroaryl group wherein the above radicals may in turn be substituted by halogen, -OH, -CN, and x is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 means
  • A is a group of the formulas COOR 2 , CN, CONR 2 2 , OR 2 and / or R 2 ,
  • R 2 is hydrogen, a C 1 -C 15 -alkyl group, C 1 -C 15 -alkoxy group, for example ethyleneoxy group or C 5 -C 20 -aryl or heteroaryl group in which the above radicals may in turn be substituted by halogen, -OH, COOZ, -CN, NZ 2 R is a bond, a divalent C 1 -C 15 -alkylene group, divalent C 1 -C 15-
  • Alkylenoxy may be substituted with halogen, -OH, COOZ, -CN, NZ 2 , Z are independently hydrogen, C1-C15-alkyl group, C1 C15
  • Alkoxy group for example, ethyleneoxy group or C5-C20 aryl or Heteroaryl group, wherein the above radicals may in turn be substituted by halogen, -OH, -CN, and x is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 means.
  • Included among the preferred monomers comprising sulfonic acid include alkenes having sulfonic acid groups, such as ethene sulfonic acid, propylene sulfonic acid, butene sulfonic acid; Acrylic acid and / or methacrylic acid compounds which have sulfonic acid groups, for example 2-sulfonomethylacrylic acid, 2-sulfonomethylmethacrylic acid, 2-sulfonomethylacrylamide and 2-sulfonomethylmethacrylamide.
  • alkenes having sulfonic acid groups such as ethene sulfonic acid, propylene sulfonic acid, butene sulfonic acid
  • Acrylic acid and / or methacrylic acid compounds which have sulfonic acid groups, for example 2-sulfonomethylacrylic acid, 2-sulfonomethylmethacrylic acid, 2-sulfonomethylacrylamide and 2-sulfonomethylmethacrylamide.
  • vinyl sulfonic acid ethene sulfonic acid
  • a preferred vinylsulfonic acid has a purity of more than 70%, in particular 90% and particularly preferably more than 97% purity.
  • the monomers comprising sulfonic acid groups can furthermore also be used in the form of derivatives, which can then be converted into the acid, wherein the conversion to the acid can also take place in the polymerized state.
  • derivatives include, in particular, the salts, the esters, the
  • composition to be used according to the invention comprises, based on its total weight, preferably at least 20% by weight, in particular at least 30% by weight and particularly preferably at least 50% by weight, of monomers comprising sulfonic acid groups.
  • the polymerizable composition may contain monomers capable of crosslinking. These are in particular compounds which have at least 2 carbon-carbon
  • R is a C 1 -C 15 -alkyl group, C 5 -C 20 -aryl or heteroaryl group, NR ' , -SO 2 , PR ' ,
  • R ' independently of one another are hydrogen, a C 1 -C 15 -alkyl group, C 1 -C 15-
  • Alkoxy group, C5-C20-aryl or heteroaryl group and n is at least 2.
  • the substituents of the above radical R are preferably halogen, hydroxyl, carboxyl, carboxyl, carboxyl esters, nitriles, amines, silyl, siloxane
  • crosslinkers are allyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetra- and polyethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, glycerol dimethacrylate,
  • epoxy acrylates for example Ebacryl, N ' , N-methylenebisacrylamide, carbinol, butadiene, isoprene, chloroprene, divinylbenzene and / or bisphenol A-dimethylacrylate.
  • crosslinkers are optional, these compounds usually in the range between 0.05 to 30 wt .-%, preferably 0.1 to 20 wt .-%, particularly preferably 1 and 10 wt .-%, based on the weight of Phosphonic acid groups comprising monomers can be used. According to a most preferred variant of the invention, however, the composition contains no crosslinkers.
  • the uncrosslinked polymers obtainable in this way can be processed more easily.
  • the composition may additionally contain other components, in particular organic and / or inorganic solvents.
  • organic solvents include in particular polar aprotic solvents, such as dimethyl sulfoxide (DMSO), esters, such as ethyl acetate, and polar protic solvents, such as alcohols, such as ethanol, propanol, isopropanol and / or butanol.
  • polar aprotic solvents such as dimethyl sulfoxide (DMSO)
  • esters such as ethyl acetate
  • polar protic solvents such as alcohols, such as ethanol, propanol, isopropanol and / or butanol.
  • inorganic solvents include in particular water, phosphoric acid and polyphosphoric acid.
  • the composition containing the phosphonic acid groups and / or monomers comprising sulfonic acid groups is radically polymerized, wherein the reaction is expediently initiated thermally, photochemically, chemically and / or electrochemically.
  • a starter solution containing at least one substance capable of forming radicals may be added to the composition.
  • at least one free-radical generator can also be added directly to the composition and dissolved, for example, by ultrasound in the composition.
  • Suitable free-radical formers include azo compounds, peroxy compounds, persulfate compounds or azoamidines. Not limiting
  • Examples include dibenzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, Dikaliumpersulfat, ammonium peroxydisulfate, 2,2'-azobis (2-methylpropionitrile) (AIBN), 2,2 'azobis- (isobutterklamidin) hydrochloride , Benzpinacol, dibenzyl derivatives, methyl ethyl ketone peroxide, 1, 1-azobiscyclohexanecarbonitrile,
  • free-radical formers which form free radicals upon irradiation.
  • free-radical formers which form free radicals upon irradiation.
  • preferred compounds include ⁇ ⁇ -
  • Diethoxyacetophenone (DEAP, Upjon Corp), n-butylbenzoin ether (®Trigonal-14, AKZO) and 2,2-dimethoxy-2-phenylacetophenone (®Igacure 651) and 1-benzoylcyclohexanol (®Igacure 184), bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (®lgacure 819) and 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-phenylpropan-1-one (®lgacure 2959), each from Ciba Geigy Corp. are commercially available.
  • ®Vazo 33 2,2'-azobis (2,4-dimethyl-4-methoxypentanenitrile)
  • ®Vazo 44WSP 2,2'-azobis (N, N'-diethyleneisobutylamidine) dihydrochloride
  • ®VA-041 2,2'-azobis [2- (5-methyl-2-imidazolin-2-yl) propane] dihydrochloride
  • ®VA-044 2,2'-azobis [2- (2-imidazoline-2 -yl) propane] dihydrochloride
  • VA-046B 2,2'-azobis [2- (2-imidazolin-2-yl) propanedisulfate dihydrate
  • ®VA-080 2,2'-azobis ⁇ 2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide
  • ®VA-085 2.2 'Azobis ⁇ 2-methyl-N- [2- (1-hydroxybuthyl)] propionamide ⁇
  • the free-radical formers preferably have a half-life in the range from 1 minute to 300 minutes, preferably in the range from 1 minute to 200 minutes, in particular in the range of 1, under the chosen polymerization conditions
  • free radical generator usually between 0.0001 and 5 wt .-%, in particular 0.01 to 3 wt .-% (based on the weight of the composition) is added to free radical generator.
  • the amount of free radical generator can vary depending on the desired
  • the polymerization can also be carried out by the action of UV light having a wavelength of less than 400 nm.
  • This polymerization method is known per se and, for example, in Hans Joerg Elias, Makromolekulare Chemie, ⁇ .conomlage, Vol
  • a membrane is irradiated with a radiation dose in the range from 1 to 300 kGy, preferably from 3 to 250 kGy and most preferably from 20 to 200 kGy.
  • the polymerization of the composition is preferably carried out at temperatures above room temperature (20 ° C) and less than 200 ° C, in particular at Temperatures between 40 ° C and 150 ° C, more preferably between 50 ° C and 120 ° C.
  • the polymerization is preferably carried out under normal pressure, but can also be effected under the action of pressure.
  • the polymers of the invention are particularly suitable for polymer electrolyte
  • Membranes in so-called PEM fuel cells. They may be used either alone or in combination with one or more polymers (B) which are not obtainable by polymerization of monomers comprising phosphonic acid groups and / or sulfonic acid groups. Particularly suitable combinations of the polymers (A) and (B) have a weight ratio of
  • compositions have proven particularly useful, which, based on their total weight, a) 40.0 to 90.0 wt .-% polymer (A) b) 1, 0 to 30.0 wt .-% polymer (B ) and c) contain from 0.0 to 50.0% by weight of phosphoric acid, the proportions by weight of the components preferably giving 100.0% by weight.
  • the composition comprises 70.0 to 90.0% by weight, preferably 75.0 to 85% by weight, of polymer (A) and 10.0 to 30.0% by weight. %, preferably 15.0 to 25.0 parts by weight
  • the composition comprises 40.0 to 60.0% by weight, preferably 45.0 to 55% by weight, of polymer (A), 5.0 to 15.0% by weight. %, preferably 7.5 to 12.5 wt .-%, polymer (B) and 30.0 to 50.0 wt .-%, preferably 35.0 to 45.0 wt .-%, phosphoric acid (H 3 PO 4 ).
  • Preferred polymers (B) include, but are not limited to, polyolefins such as poly (chloroprene), polyacetylene, polyphenylene, poly (p-xylylene), polyarylmethylene, polystyrene, polymethylstyrene, polyvinyl alcohol, polyvinyl acetate, polyvinyl ether, polyvinylamine, poly (N-vinylacetamide), Polyvinylimidazole, polyvinylcarbazole,
  • polyolefins such as poly (chloroprene), polyacetylene, polyphenylene, poly (p-xylylene), polyarylmethylene, polystyrene, polymethylstyrene, polyvinyl alcohol, polyvinyl acetate, polyvinyl ether, polyvinylamine, poly (N-vinylacetamide), Polyvinylimidazole, polyvinylcarbazole,
  • Polyvinyl pyrrolidone polyvinyl pyridine, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinyl difluoride, polyhexafluoropropylene, polyethylene tetrafluoroethylene, copolymers of PTFE with hexafluoropropylene, with perfluoropropyl vinyl ether, with trifluoronitrosomethane, with carbalkoxy perfluoroalkoxy vinyl ether, polychlorotrifluoroethylene, polyvinyl fluoride,
  • Polymers C-S bonds in the main chain for example polysulfide ethers, polyphenylene sulfide, polyether sulfone, polysulfone, polyether ether sulfone, polyaryl ether sulfone, polyphenylene sulfone, polyphenylene sulfide sulfone,
  • Main chain polymer C-N bonds for example, polyimines, polyisocyanides, polyetherimine, polyetherimides, poly (trifluoro-methyl-bis (phthalimido) -phenyl, polyaniline, polyaramides, polyamides, polyhydrazides, polyurethanes, polyimides, polyazoles, polyazole-ether-ketone, polyureas, polyazines;
  • Liquid crystalline polymers especially Vectra and
  • Inorganic polymers for example polysilanes, polycarbosilanes, polysiloxanes, polysilicic acid, polysilicates, silicones, polyphosphazenes and polythiazyl. These polymers can be used singly or as a mixture of two, three or more polymers.
  • polymers containing at least one nitrogen atom, oxygen atom and / or sulfur atom in a repeat unit Particular preference is given to polymers which contain at least one aromatic ring having at least one nitrogen, oxygen and / or sulfur heteroatom per
  • polymers based on polyazoles are particularly preferred. These basic polyazole polymers contain at least one aromatic ring having at least one nitrogen heteroatom per repeat unit.
  • the aromatic ring is preferably a five- or six-membered ring having one to three nitrogen atoms which may be fused to another ring, especially another aromatic ring.
  • Polymers based on polyazole generally contain recurring azole units of the general formula (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 (XVI) and / or (XVII) and / or (XVIII) and / or (XIX) and / or (XX) and / or (XXII) and / or (XVIII) and / or (XIX) and / or (XX) and / or or (XXI) and / or (XXII) and / or (XXII)) and / or (X
  • Ar are the same or different and represent a four-membered aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 1 are the same or different and represent a divalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 2 is the same or are different and represent a two- or three-membered aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 3 are the same or different and are a trivalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 4 are the same or different and are a trivalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 5 are the same or different and represent a four- membered aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 6 are the same or different and are a divalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 7 are the same or different and are a divalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 8 is the same or are different and represent a trivalent aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 5 are the same or different and represent a four- membered aromatic or heteroaromatic group which may be mononuclear or polynuclear
  • Ar 6 are the same or different and are a divalent aromatic or heteroaromatic group which may be mononuclear or polyn
  • Ar 9 are the same or different and represent a di- or tri- or tetravalent aromatic or heteroaromatic group which may be mononuclear or polynuclear,
  • Ar 10 are the same or different and represent a divalent or trivalent aromatic or heteroaromatic group which may be mononuclear or polynuclear,
  • Ar 11 are the same or different and represent a divalent aromatic or heteroaromatic group which may be mononuclear or polynuclear, X is identical or different and represents oxygen, sulfur or an amino group which has one hydrogen atom, a 1-20 carbon atoms group, preferably a branched or unbranched alkyl or
  • Alkoxy group, or an aryl group as further radical R is identical or different hydrogen, an alkyl group and an aromatic group is the same or different hydrogen, an alkyl group and an aromatic group is provided with the proviso that R in formula XX is a divalent group, and n, m is an integer greater than or equal to 10, preferably greater than or equal to 100.
  • Preferred aromatic or heteroaromatic groups are derived from benzene, naphthalene, biphenyl, diphenyl ether, diphenylmethane, diphenyldimethylmethane, Bisphenone, diphenylsulfone, thiophene, furan, pyrrole, thiazole, oxazole, imidazole, isothiazole, isoxazole, pyrazole, 1, 3,4-oxadiazole, 2,5-diphenyl-1, 3,4-oxadiazole, 1, 3,4- Thiadiazole, 1, 3,4-triazole, 2,5-diphenyl-1, 3,4-triazole, 1, 2,5-triphenyl-1, 3,4-triazole, 1, 2,4-oxadiazole, 1, 2,4-thiadiazole, 1, 2,4-triazole, 1, 2,3-triazole, 1, 2,3,4-tetrazole, benzo [b] thiophene, benzo [
  • Phenanthroline and phenanthrene which may optionally be substituted.
  • the substitution pattern of Ar 1 , Ar 4 , Ar 6 , Ar 7 , Ar 8 , Ar 9 , Ar 10 , Ar 11 is arbitrary, in the case of phenylene, for example, Ar 1 , Ar 4 , Ar 6 , Ar 7 , Ar 8 , Ar 9 , Ar 10 , Ar 11 are ortho, meta and para-phenylene. Particularly preferred groups are derived from benzene and biphenylene, which may optionally also be substituted.
  • Preferred alkyl groups are short chain alkyl groups of 1 to 4 carbon atoms, such as. For example, methyl, ethyl, n- or i-propyl and t-butyl groups.
  • Preferred aromatic groups are phenyl or naphthyl groups.
  • the alkyl groups and the aromatic groups may be substituted.
  • Preferred substituents are halogen atoms such as. As fluorine, amino groups,
  • Hydroxy groups or short-chain alkyl groups such as. For example, methyl or ethyl groups.
  • the polyazoles can also have different recurring units which differ, for example, in their radical X. Preferably, however, it has only the same X radicals in a repeating unit.
  • Other preferred polyazole polymers are polyimidazoles, polybenzothiazoles, polybenzoxazoles, polyoxadiazoles, polyquinoxalines, polythiadiazoles, poly (pyridines), poly (pyrimidines), and poly (tetrazapyrenes).
  • the polymer containing recurring azole units is a copolymer or a blend containing at least two units of the formulas (I) to (XXII) which differ from one another.
  • the polymers can be present as block copolymers (diblock, triblock), random copolymers, periodic copolymers and / or alternating polymers.
  • the polymer containing recurring azole units is a polyazole which contains only units of the formula (I) and / or (II).
  • the number of repeating azole units in the polymer is preferably an integer greater than or equal to 10.
  • Particularly preferred polymers contain at least 100 recurring azole units.
  • Benzimidazole units preferred. Some examples of the most useful polymers containing recurring benzimidazole units are represented by the following formulas:
  • n and m is an integer greater than or equal to 10, preferably greater than or equal to 100.
  • polyazole polymers are polyimidazoles, polybenzimidazole ether ketone, polybenzothiazoles, polybenzoxazoles, polytriazoles, polyoxadiazoles, polythiadiazoles, polypyrazoles, polyquinoxalines, poly (pyridines), poly (pyrimidines), and poly (tetrazapyrene).
  • Preferred polyazoles are characterized by a high molecular weight. This is especially true for the polybenzimidazoles. Measured as intrinsic viscosity, this is preferably at least 0.2 dl / g, preferably 0.7 to 10 dl / g, in particular 0.8 to 5 dl / g.
  • Celazole is particularly preferred from Celanese.
  • the properties of the polymer film and polymer membrane can be improved by screening the starting polymer as described in German Patent Application No. 10129458.1.
  • Aromatic sulfonic acid groups are groups in which the sulfonic acid group (-SO 3 H) is covalently bonded to an aromatic or heteroaromatic group.
  • the aromatic group can be a part of
  • Backbone of the polymer or a part of a side group, with polymers having aromatic groups in the main chain are preferred.
  • the sulfonic acid groups can also be used in many cases in the form of the salts.
  • derivatives, for example esters, especially methyl or Ethyl ester, or halides of the sulfonic acids are used, which are converted during operation of the membrane into the sulfonic acid.
  • the polymers modified with sulfonic acid groups preferably have a content of sulfonic acid groups in the range from 0.5 to 3 meq / g, preferably 0.5 to
  • the sulfonic acid groups are converted into the free acid.
  • the polymer is treated in a known manner with acid, wherein excess acid is removed by washing.
  • the sulfonated polymer is first treated for 2 hours in boiling water. Subsequently, excess water is blotted and the sample is dried for 15 hours at 160 ° C in a vacuum drying oven at p ⁇ 1 mbar. Then the dry weight of the membrane is determined.
  • the thus dried polymer is then dissolved in DMSO at 80 ° C for 1 h. The solution is then titrated with 0.1 M NaOH. From the
  • IEC ion exchange capacity
  • Sulfonic acid groups are prepared for example by sulfonation of polymers. Methods for sulfonating polymers are described in F. Kucera et. al. Polymer Engineering and Science 1988, Vol. 38, No. 5, 783-792. Here, the sulfonation conditions can be chosen so that a low degree of sulfonation is formed (D E-A-19959289).
  • perfluorinated polymers can be prepared as described in US-A-5422411 by copolymerization of trifluorostyrene and sulfonyl-modified trifuorostyrene.
  • high temperature stable thermoplastics which have sulfonic acid groups attached to aromatic groups.
  • such Polymers in the main chain on aromatic groups.
  • sulfonated polyether ketones DE-A-4219077, WO96 / 01177
  • sulfonated polysulfones J. Membr. Sei. 83 (1993) p.211
  • sulfonated polyphenylene sulfide D EA-19527435
  • polymers with sulfonic acid groups bound to aromatics described above can be used individually or as a mixture, particular preference being given to mixtures having polymers with aromatics in the main chain.
  • Preferred polymers include polysulfones, especially polysulfone having aromatics in the backbone.
  • preferred polysulfones and polyether sulfones have a melt volume rate MVR 300/21, 6 is less than or equal to 40 cm 3/10 min, especially less than or equal to 30 cm 3/10 min and particularly preferably less than or equal to 20 cm 3 / 10 min measured to ISO 1133.
  • Range of 0.1 to 50, preferably from 0.2 to 20, particularly preferably from 1 to 10 are.
  • Preferred polymers include polysulfones, especially polysulfone having aromatic and / or heteroaromatic groups in the backbone.
  • preferred polysulfones and polyether sulfones have a melt volume rate MVR 300/21, 6 is less than or equal to 40 cm 3/10 min, especially less than or equal to 30 cm 3/10 min and particularly preferably less than or equal to 20 cm 3 / 10 min measured to ISO 1133.
  • the number average molecular weight of the polysulfones is greater than 30,000 g / mol.
  • the polymers based on polysulfone include, in particular, polymers which have recurring units with linking sulfone groups corresponding to the general formulas A, B, C, D, E, F and / or G:
  • radicals R independently of one another or different, represent an aromatic or heteroaromatic group, these radicals having been explained in more detail above.
  • these radicals include in particular 1, 2-phenylene, 1, 3-phenylene, 1, 4-phenylene, 4,4'-biphenyl, pyridine, quinoline, naphthalene, phenanthrene.
  • Preferred polysulfones for the purposes of the present invention include homopolymers and copolymers, for example random copolymers.
  • Particularly preferred polysulfones comprise recurring units of the formulas H to N:
  • the polysulfones described above may under the trade names ® Victrex 200 P, ® Victrex 720 P, ® Ultrason E, ® Ultrason S, ® Mindel, ® Radel A, ® Radel R, ® Victrex HTA, ® Astrel and ® Udel be obtained commercially.
  • polyether ketones polyether ketone ketones
  • polyether ether ketones polyether ketone ketones
  • polyaryl ketones are particularly preferred. These high performance polymers are known per se and can be obtained commercially under the trade names Victrex® PEEK TM, ® Hostatec, ® Kadel.
  • fillers in particular proton-conductive fillers, and additional acids.
  • Such substances preferably have an intrinsic conductivity at 100 ° C. of at least 10 -6 S / cm, in particular 10 -5 S / cm.
  • Non-limiting examples of proton-conducting fillers are:
  • Sulfates in particular CsHSO 4 , Fe (SO 4 ) 2 , (NH 4 ) 3 H (SO 4 ) 2 , LiHSO 4 , NaHSO 4 , KHSO 4 ,
  • Phosphates in particular Zr 3 (PO 4 ) 4 , Zr (HPO 4 ) 2 , HZr 2 (PO 4 ) 3 , UO 2 PO 4 .3H 2 O,
  • HSbTeO 6 H 5 Ti 4 O 9 , HSbO 3 , H 2 MoO 4 , Selenites and arsenites, especially (NH 4 ) 3 H (SeO 4 ) 2 , UO 2 AsO 4 , (NH 4 ) 3 H (SeO 4 ) 2 , KH 2 AsO 4 , Cs 3 H (SeO 4 ) 2) Rb 3 H (SeO 4 ) 2 , phosphides, in particular ZrP, TiP, HfP, oxides, in particular Al 2 O 3 , Sb 2 O 5 , ThO 2 , SnO 2 , ZrO 2 , MoO 3 , silicates, in particular zeolites, zeolites (NH 4 +), Phyllosilicates, framework silicates, H-
  • Fibers in particular glass fibers, glass powder and / or polymer fibers, preferably based on polyazoles.
  • the membrane comprises at most 80% by weight, preferably at most 50% by weight and particularly preferably at most 20% by weight of additives.
  • this membrane may also contain perfluorinated sulfonic acid additives
  • Non-limiting examples of perfluorinated sulfonic acid additives are: trifluoromethanesulfonic acid, potassium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, lithium trifluoromethanesulfonate,
  • Ammonium trifluoromethanesulfonate potassium perfluorohexanesulfonate, sodium perfluorohexanesulfonate, lithium perfluorohexanesulfonate, ammonium perfluorohexanesulfonate, perfluorohexanesulfonic acid, potassium nonafluorobutanesulfonate, sodium nonafluorobutanesulfonate, Lithium nonafluorobutanesulfonate, ammonium nonafluorobutanesulfonate, cesium nonafluorobutanesulfonate, triethylammonium perfluorohexasulfonate and perfluorosulfoimides.
  • the preparation of the membrane can in a known manner, for example by
  • Suitable carriers are all suitable carriers under the conditions as inert.
  • These supports include, in particular, films of polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyhexafluoropropylene,
  • the membrane components in at least one polar, aprotic solvents, such as
  • DMAc Dimethylacetamide
  • the film thus obtained can be treated with a washing liquid as described in German patent application DE 101 098 29.
  • the cleaning of the film from solvent residues described in the German patent application surprisingly improves the mechanical properties of the film. These properties include in particular the modulus of elasticity, the tear strength and the fracture toughness of the film.
  • the polymer film may have further modifications, for example by crosslinking, as described in German patent application DE 101 107 52 or in WO 00/44816.
  • the polymer film used consists of a basic polymer and at least one blend component additionally contains a crosslinker, as in the German
  • the membrane is doped with at least one acid.
  • Acids in this context include all known Lewis and Br ⁇ nsted acids, preferably Lewis and Bransted inorganic acids.
  • heteropolyacids mean inorganic polyacids having at least two different central atoms, which in each case consist of weak, polybasic oxygen acids of a metal (preferably Cr, Mo, V, W) and a nonmetal (preferably As, I, P, Se, Si, Te) as partial mixed anhydrides.
  • a metal preferably Cr, Mo, V, W
  • a nonmetal preferably As, I, P, Se, Si, Te
  • the degree of doping can influence the conductivity of the membrane.
  • the conductivity increases with increasing concentration of dopant until a maximum value is reached.
  • the degree of doping is given as mol of acid per mole of repeat unit of the polymer.
  • Invention is a degree of doping between 3 and 80, preferably between 5 and 60, in particular between 12 and 60, preferably.
  • Particularly preferred dopants are sulfuric acid and phosphoric acid, as well as compounds which release these acids, for example upon hydrolysis.
  • a most preferred dopant is phosphoric acid (H 3 PO 4 ).
  • highly concentrated acids are generally used.
  • the concentration of the phosphoric acid is at least 50% by weight, in particular at least 80% by weight, based on the weight of the doping agent.
  • proton conductive membranes can also be obtained by a process comprising the steps
  • step II heating the solution obtainable according to step I) under inert gas to temperatures of up to 400 ° C,
  • doped membranes can be obtained by a process comprising the steps
  • step C) heating of the sheet / layer obtainable according to step B) under inert gas to temperatures of up to 350 ° C, preferably up to 280 ° C to form the polyazole polymer.
  • step A The aromatic or heteroaromatic carboxylic acid and tetra-amino compounds to be used in step A) have been described above.
  • the polyphosphoric acid used in step A) is preferably commercially available polyphosphoric acids, as are obtainable, for example, from Riedel-de Haen.
  • the polyphosphoric acids H n + 2 P n O 3n + I (n> 1) usually have a content calculated as P 2 O 5 (acidimetric) of at least 83%.
  • P 2 O 5 acidimetric
  • the mixture produced in step A) has a weight ratio of the acid to
  • step B) The layer formation according to step B) is preferably carried out by means of known measures (casting, spraying, doctoring) from the prior art for
  • Suitable carriers are all suitable carriers under the conditions as inert.
  • the solution may optionally be treated with phosphoric acid (concentrated phosphoric acid, 85%). This allows the viscosity to be adjusted to the desired value and the formation of the membrane can be facilitated.
  • the layer produced according to step B) has a thickness between 20 and 4000 ⁇ m, preferably between 30 and 3500 ⁇ m, in particular between 50 and 3000 ⁇ m.
  • step C Treatment of the polymer layer produced according to step C) in the presence of moisture at temperatures and for a sufficient time until the layer has sufficient strength for use in fuel cells.
  • the treatment can be carried out so far that the membrane is self-supporting, so that it can be detached from the carrier without damage.
  • step C) the flat structure obtained in step B) is set to a
  • the inert gases to be used in step C) are known in the art. These include in particular nitrogen and noble gases, such as neon, argon, helium.
  • step A) by heating the mixture from step A) to temperatures of up to 350 ° C., preferably up to 280 ° C., the formation of oligomers and / or polymers can already be effected. Depending on the selected temperature and duration, then the heating in step C) can be omitted partially or completely.
  • This variant is also the subject of the present invention.
  • the treatment of the membrane in step D) is carried out at temperatures above 0 ° C and below 150 ° C, preferably at temperatures between 10 ° C and 120 ° C, in particular between room temperature (20 ° C) and 90 ° C, in the presence of
  • the treatment is preferably carried out under normal pressure, but can also be effected under the action of pressure. It is essential that the treatment is carried out in the presence of sufficient moisture, whereby the possibly present polyphosphoric acid by partial hydrolysis
  • Training low molecular weight polyphosphoric acid and / or phosphoric acid contributes to the solidification of the membrane.
  • the partial hydrolysis of the polyphosphoric acid in step D) leads to a solidification of the membrane and a decrease in the layer thickness and formation of a membrane having a thickness between 15 and 3000 .mu.m, preferably between 20 and 2000 .mu.m, in particular between 20 and 1500 .mu.m, the self-supporting is.
  • the intra- and intermolecular structures (interpenetrating networks IPN) present in the polyphosphoric acid layer according to step B) result in an orderly membrane formation in step C) which is responsible for the particular properties of the membrane formed.
  • the upper temperature limit of the treatment according to step D) is usually 150 ° C. With extremely short exposure to moisture, for example from superheated steam, this steam may also be hotter than 150 ° C. Essential for the upper temperature limit is the duration of the treatment.
  • the partial hydrolysis (step D) can also be carried out in climatic chambers in which the hydrolysis can be controlled in a controlled manner under defined action of moisture.
  • the moisture can be adjusted in a targeted manner by the temperature or saturation of the contacting environment, for example gases, such as air, nitrogen, carbon dioxide or other suitable gases, or water vapor.
  • gases such as air, nitrogen, carbon dioxide or other suitable gases, or water vapor.
  • the duration of treatment depends on the parameters selected above.
  • the duration of treatment depends on the thickness of the membrane.
  • the treatment time is between a few seconds to minutes, for example under the action of superheated steam, or up to full days, for example in air at room temperature and low relative humidity.
  • the treatment time is preferably between 10 seconds and 300 hours, in particular 1 minute to 200 hours.
  • the treatment duration is between 1 and 200 hours.
  • the membrane obtained according to step D) can be made self-supporting, i. It can be detached from the carrier without damage and then optionally further processed directly.
  • a concentration (mol of phosphoric acid relative to a repeat unit of the formula (I), for example polybenzimidazole) is preferably between 10 and 50, in particular between 12 and 40.
  • doped membranes are formed by the use of at least one acid, preferably phosphoric acid or polyphosphoric acid, in particular polyphosphoric acid, can be prepared, the production of these films can also be carried out by a method comprising the steps
  • step 2) dissolving the solid prepolymer obtained according to step 1) and the polymer according to the invention in at least one acid, preferably
  • Phosphoric acid or polyphosphoric acid in particular polyphosphoric acid,
  • step 3) heating the solution obtainable according to step 2) under inert gas to temperatures of up to 300 ° C, preferably up to 280 ° C, to form the dissolved polyazole polymer, 4) forming a membrane using the solution according to step 3) a carrier and 5) treatment of the membrane formed in step 4) until it is self-supporting.
  • the membrane of the invention is characterized by an excellent property profile.
  • the water content of the proton-conducting membrane is preferably at most 15% by weight, more preferably at most 10% by weight and most preferably at most 5% by weight.
  • preferred membranes therefore comprise fractions of polymers comprising low molecular weight phosphonic acid groups.
  • the proportion of polymers comprising phosphonic acid groups having a degree of polymerization in the range from 2 to 20 is preferably at least 10% by weight, particularly preferably at least 20% by weight, based on the weight of the polymers comprising phosphonic acid groups.
  • the layer thickness of the membrane is expediently between 5 and 2000 ⁇ m, preferably between 15 and 1000 ⁇ m, preferably between 20 and 500 ⁇ m, in particular between 30 and 250 ⁇ m.
  • the membrane is preferably self-supporting, i. It can be detached from a carrier without damage and then optionally further processed directly.
  • the membrane has a high mechanical stability.
  • This size results from the hardness of the membrane, which is determined by means of microhardness measurement according to DIN 50539.
  • the membrane is loaded with a Vickers diamond successively within 20 s up to a force of 3 mN and the penetration depth is determined.
  • the hardness at room temperature is at least 0.01 N / mm 2 , preferably at least 0.1 N / mm 2 and very particularly preferably at least 1 N / mm 2 , without this being a restriction.
  • the force is kept constant at 3 mN for 5 s and the creep is calculated from the penetration depth.
  • creep CHU is 0.003 / 20/5 under these conditions less than 20%, preferably less than 10%, and most preferably less than 5%.
  • the module determined by microhardness measurement is
  • YHU at least 0.5 MPa, in particular at least 5 MPa and most preferably at least 10 MPa, without this being a restriction.
  • the hardness of the membrane refers both to a surface that does not
  • Catalyst layer as well as on a side having a catalyst layer.
  • the membrane can be thermally, photochemically, chemically and / or electrochemically crosslinked to further improve its properties of the membrane.
  • the membrane may be heated to a temperature of at least 150 ° C 1, preferably at least 200 ° C, and more preferably at least 250 ° C.
  • the thermal crosslinking takes place in the presence of oxygen.
  • the oxygen concentration in this process step is usually in the range of 5 to 50% by volume, preferably 10 to 40% by volume, without this being intended to limit it.
  • the radiation dose here is preferably between 5 and 250 kGy, in particular 10 to 200 kGy.
  • the irradiation can be carried out in air or under inert gas. As a result, the performance properties of the membrane, in particular their durability are improved.
  • the duration of the crosslinking reaction can be in a wide range. In general, this reaction time is in the range of 1 second to 10 hours, preferably 1 minute to 1 hour, without this being a restriction.
  • the membrane according to elemental analysis comprises at least 3 wt .-%, preferably at least 5 wt .-% and particularly preferably at least 7 wt .-% sulfur and / or phosphorus, in particular phosphorus, each based on the total weight of Membrane.
  • the proportion of sulfur and / or phosphorus can via a
  • Elemental analysis can be determined.
  • the membrane is dried at 110 ° C for 3 hours in vacuo (1 mbar).
  • the membrane preferably has a content of sulfonic acid groups and / or phosphonic acid groups, in particular of phosphonic acid groups, of at least
  • IEC ion exchange capacity
  • the acid groups are transferred to the free acid and then titrated with 0.1 M NaOH. From the consumption of acid to the
  • the polymer membrane according to the invention has improved material properties compared to previously known doped polymer membranes. In particular, they show better performance compared to known doped polymer membranes. This is due in particular to an improved proton conductivity. This is at temperatures of 120 ° C at least 1 mS / cm, preferably at least 2 mS / cm, in particular at least 5 mS / cm. Furthermore, the membranes show a high conductivity even at a temperature of 7O 0 C. Among other things, the conductivity depends on the sulfonic acid group content of the membrane. The higher this proportion, the better the conductivity at low temperatures. In this case, an inventive
  • Membrane be moistened at low temperatures.
  • the compound used as an energy source for example hydrogen
  • the compound used as an energy source for example hydrogen
  • the water formed by the reaction is sufficient to achieve humidification.
  • the specific conductivity is measured by means of impedance spectroscopy in a 4-PoI arrangement in the potentiostatic mode and using platinum electrodes (wire, 0.25 mm diameter). The distance between the current-collecting electrodes is 2 cm.
  • the obtained spectrum is evaluated with a simple model consisting of a parallel arrangement of an ohmic resistance and a capacitance.
  • the sample cross-section of the phosphoric acid-doped membrane is measured immediately prior to sample assembly. To measure the temperature dependence, the measuring cell is brought to the desired temperature in an oven and via an in the immediate
  • Proximity-positioned PMOO thermocouple regulated. After reaching the temperature, the sample is held at this temperature for 10 minutes before starting the measurement.
  • the membrane In addition to the polymer electrolyte membrane, the membrane
  • Electrode unit further at least two electrochemically active electrodes (anode and cathode), which are separated by the polymer electrolyte membrane.
  • electrochemically active indicates that the electrodes are capable of catalyzing the oxidation of hydrogen and / or at least one reformate and the reduction of oxygen
  • Electrode means that the material is electrically conductive, and the electrode may optionally comprise a noble metal layer Such electrodes are known and are described, for example, in US 4,191,618, US 4,212,714 and US 4,333,805.
  • the electrodes preferably include gas diffusion layers in contact with a catalyst layer.
  • gas diffusion layers usually planar, electrically conductive and acid-resistant structures are used. These include, for example, graphite fiber papers, carbon fiber papers, graphite fabrics and / or papers rendered conductive by the addition of carbon black. Through these layers, a fine distribution of the gas and / or liquid streams is achieved.
  • gas diffusion layers can be used which contain a mechanically stable support material, which with at least one electrically conductive material, for.
  • a mechanically stable support material which with at least one electrically conductive material, for.
  • carbon for example carbon black
  • Particularly suitable support materials for these purposes include fibers, for example in the form of nonwovens, papers or fabrics, in particular carbon fibers, glass fibers or fibers containing organic polymers, for example polypropylene, polyester (polyethylene terephthalate), polyphenylene sulfide or polyether ketones. Further details of such diffusion layers can be found, for example, in WO 9720358.
  • the gas diffusion layers preferably have a thickness in the range from 80 ⁇ m to 2000 ⁇ m, in particular in the range from 100 ⁇ m to 1000 ⁇ m and particularly preferably in the range from 150 ⁇ m to 500 ⁇ m.
  • the gas diffusion layers favorably have a high porosity. This is preferably in the range of 20% to 80%.
  • the gas diffusion layers may contain conventional additives. These include, but are not limited to, fluoropolymers, e.g. Polytetrafluoroethylene (PTFE) and surface-active substances.
  • fluoropolymers e.g. Polytetrafluoroethylene (PTFE)
  • surface-active substances e.g. fluoropolymers, e.g. Polytetrafluoroethylene (PTFE) and surface-active substances.
  • At least one of the gas diffusion layers may consist of a compressible material.
  • a compressible material is characterized by the property that the gas diffusion layer can be pressed without loss of its integrity by pressure on half, in particular to one third of its original thickness.
  • This property generally comprises gas diffusion layers
  • the catalyst layer or catalyst layers contain or contain catalytically active substances. These include precious metals of the platinum group, ie Pt, Pd, Ir, Rh, Os, Ru, or the precious metals Au and Ag. It is also possible to use alloys of all the aforementioned metals. Further, at least one catalyst layer may contain alloys of the platinum group elements with base metals such as Fe, Co, Ni, Cr, Mn, Zr, Ti, Ga, V, etc. In addition, the oxides of the aforementioned noble metals and / or non-precious metals can be used.
  • the catalytically active particles which comprise the abovementioned substances can be used as metal powder, so-called black noble metal, in particular platinum and / or platinum alloys.
  • Such particles generally have a size in the range of 5 nm to 200 nm, preferably in the range of 7 nm to 100 nm.
  • the metals can also be used on a carrier material.
  • this support comprises carbon, which can be used in particular in the form of carbon black, graphite or graphitized carbon black.
  • electrically conductive metal oxides such as, for example, SnO x , TiO x , or phosphates, such as, for example, FePO x , NbPO x , Zr y (PO x ) z as carrier material.
  • the indices x, y and z denote the oxygen or metal content of the individual compounds, which may be in a known range, since the transition metals can assume different oxidation states.
  • Metal-carrier compound is generally in the range of 1 to 80 wt .-%, preferably 5 to 60 wt .-% and particularly preferably 10 to 50 wt .-%, without this being a restriction.
  • the particle size of the carrier in particular the size of the carbon particles, is preferably in the range of 20 to 1000 nm, in particular 30 to 100 nm.
  • the size of the metal particles present thereon is preferably in the range of 1 to 20 nm, in particular 1 to 10 nm and more preferably 2 to 6 nm.
  • the sizes of the different particles represent mean values and can be determined by transmission electron microscopy or powder X-ray diffractometry.
  • the catalytically active particles set forth above can generally be obtained commercially.
  • the catalytically active layer may contain conventional additives. These include fluoropolymers such as polytetrafluoroethylene (PTFE), proton-conducting ionomers and surface-active substances.
  • PTFE polytetrafluoroethylene
  • the weight ratio of fluoropolymer to catalyst material comprising at least one noble metal and optionally one or more support materials, greater than 0.1, wherein this ratio is preferably in the range of 0.2 to 0.6.
  • the catalyst layer preferably has a thickness in the range from 1 to 1000 ⁇ m, in particular in the range from 5 to 500, preferably in the range from 10 to 300 ⁇ m.
  • This value represents an average value that can be determined by measuring the layer thickness in the cross-section of images that can be obtained with a scanning electron microscope (SEM).
  • the noble metal content of the catalyst layer is 0.1 to 10.0 mg / cm 2 , preferably 0.3 to 6.0 mg / cm 2 and more preferably 0.3 to 3.0 mg / cm 2 , These values can be determined by elemental analysis of a flat sample.
  • the electrochemically active area of the catalyst layer designates the area which is in contact with the polymer electrolyte membrane and at which the above-described redox reactions can take place.
  • the present invention enables the formation of particularly large electrochemically active areas.
  • the size of this electrochemically active surface is at least 2 cm 2 , in particular at least 5 cm 2 and preferably at least 10 cm 2 , without this being a restriction.
  • the term electrode means that the material has an electron conductivity, wherein the electrode designates the electrochemically active region.
  • the polymer electrolyte membrane has an inner portion that is in contact with a catalyst layer and an outer portion that is not provided on the surface of a gas diffusion layer. Provided in this context means that the inner area does not overlap
  • Has a region having a gas diffusion layer if a consideration is made perpendicular to the surface of a gas diffusion layer or the outer region of the polymer electrolyte membrane, so that only after contacting the polymer electrolyte membrane with the gas diffusion layer an assignment can be made.
  • the outer region of the polymer electrolyte membrane may have a single-layered construction.
  • the outer portion of the polymer electrolyte membrane is generally made of the same material as the inner portion of the polymer electrolyte membrane.
  • the outer region of the polymer electrolyte membrane may in particular comprise at least one further layer, preferably at least two further layers.
  • the outer region of the polymer electrolyte membrane has at least two or at least three components.
  • the thickness of all components of the outer region of the polymer electrolyte membrane is greater than the thickness of the inner region of the polymer electrolyte membrane.
  • the thickness of the outer area refers to the sum of the thicknesses of all components of the outer area.
  • the components of the outer region result from the vector parallel to the surface of the outer region of the polymer electrolyte membrane, wherein the layers that intersect this vector are to be counted among the components of the outer region.
  • the outer region preferably has a thickness in the range from 80 ⁇ m to 4000 ⁇ m, in particular in the range from 120 ⁇ m to 2000 ⁇ m and particularly preferably in the range from 150 ⁇ m to 800 ⁇ m.
  • the thickness of all components of the outer region is 50% to 100%, preferably 65% to 95% and particularly preferably 75% to 85%, based on the sum of the thickness of all components of the inner region.
  • the thickness of the components of the outer region in this case refers to the thickness of these components after a first pressing, which takes place at a pressure of 5 N / mm 2 , preferably 10 N / mm 2 over a period of 1 minute.
  • the components of the inner region refer to the thicknesses of the layers used, without any need for compression.
  • the thickness of all components of the inner region generally results from the sum of the thicknesses of the membrane, the catalyst layers and the
  • the thickness of the layers is determined using a digital thickness gauge from Mitutoyo.
  • the contact pressure of the two circular flat contact surfaces during the measurement is 1 PSI, the diameter of the contact surface is 1 cm.
  • the catalyst layer is generally not self-supporting but is commonly applied to the gas diffusion layer and / or the membrane. In this case, part of the catalyst layer can diffuse, for example, into the gas diffusion layer and / or the membrane, whereby transition layers form. This can also lead to the fact that the catalyst layer can be regarded as part of the gas diffusion layer.
  • the thickness of the catalyst layer results from the measurement of the thickness of the layer to which the catalyst layer has been applied, for example the gas diffusion layer or the membrane, this measurement giving the sum of the catalyst layer and the corresponding layer, for example the
  • the thickness of the components of the outer region decreases at a temperature of 80 ° C and a pressure of 5 N / mm 2 over a period of 5 hours at most by 5%, this decrease in thickness is determined after a first pressing, which at a pressure of 5 N / mm 2 , preferably 10 N / mm 2 over a period of 1 minute.
  • Area of the polymer electrolyte membrane is carried out by a hydraulic press with heated pressing plates.
  • the hydraulic press has the following technical data:
  • the press has a force range of 50-50000 N with a maximum pressing surface of 220 x 220 mm 2 .
  • the resolution of the pressure sensor is ⁇ 1 N.
  • the pressure plates are fitted with an inductive displacement sensor with a measuring range of 10 mm.
  • the resolution of the displacement sensor is ⁇ 1 ⁇ m.
  • the press plates can be operated in a temperature range of RT - 200 ° C.
  • the press is operated by means of a PC with appropriate software in force-controlled mode.
  • the data from the force and displacement sensors are recorded and displayed in real time at a data rate of up to 100 measured data / second.
  • the material to be tested is cut into an area of 55 x 55 mm 2 and placed between the press plates preheated to 80 °, 120 ° C and 160 ° C respectively.
  • the press plates are closed and an initial force of 12ON applied, so that the control loop of the press is closed.
  • the position sensor is set to 0 at this point.
  • a previously programmed pressure ramp is traversed.
  • the pressure is increased at a rate of 2 N / mm 2 s to a predetermined value, for example, 5, 10, 15 or 20 N / mm 2 and held at this value for at least 5 hours.
  • the pressure is reduced to 0 N / mm 2 with a ramp of 2 N / mm 2 s and the press is opened.
  • the relative and / or absolute change in thickness can be read from a deformation curve recorded during the pressure test or measured by a standard thickness gauge measurement after the pressure test.
  • the outer region components is generally achieved through the use of polymers having high pressure stability.
  • the polymer electrolyte membrane in the outer region may have a particularly high degree of crosslinking, which can be achieved by a specific irradiation, which was previously described.
  • the outer region membrane is irradiated with a dose of at least 100 kGy, preferably at least 132 kGy and more preferably at least 200 kGy.
  • the inner region of the membrane is preferably irradiated with at most 130 kGy, preferably at most 99 kGy and particularly preferably at most 80 kGy.
  • the ratio of the irradiation power of the outer region to the irradiation power of the inner region is preferably at least 1.5, more preferably at least 2, and most preferably at least 2.5.
  • the irradiation of the outer region may furthermore preferably take place with a UV lamp having a power of at least 5OW, in particular 100W, and particularly preferably 200W.
  • the duration can be within a wide range. Preference is given to irradiating for at least one minute, in particular at least 30 minutes and more preferably at least 5 hours, in many cases irradiation of up to 30 hours, in particular up to 10 hours, being sufficient.
  • the ratio of the irradiation time of the outer region to the irradiation time of the inner region is preferably at least 1.5, more preferably at least 2, and most preferably at least 2.5
  • these materials generally exhibit high pressure stability.
  • the thickness of the outer region components increases with one
  • the outer region comprises at least one, preferably at least two polymer layers having a thickness greater than or equal to 10 ⁇ m, the polymers of these layers each having an E modulus of at least 6 N / mm 2 , preferably at least 7 N / mm 2 , measured at 80 ° C, preferably at 160 ° C and an elongation of 100%.
  • a layer may be applied by thermoplastic methods, for example injection molding or extrusion. Accordingly, a layer is preferably made of a meltable polymer.
  • Polymers preferably used in the context of the present invention preferably have a long-term use temperature of at least 190 ° C., preferably at least 220 ° C. and particularly preferably at least 250 ° C. measured according to
  • the preferred meltable polymers include in particular fluoropolymers, such as poly (tetrafluoroethylene-co-hexafluoropropylene) FEP, Polyvinylidene fluoride PVDF, perfluoroalkoxy polymer PFA, poly (tetrafluoroethylene-co-perfluoro (methylvinylether)) MFA.
  • fluoropolymers such as poly (tetrafluoroethylene-co-hexafluoropropylene) FEP, Polyvinylidene fluoride PVDF, perfluoroalkoxy polymer PFA, poly (tetrafluoroethylene-co-perfluoro (methylvinylether)) MFA.
  • One or both layers may include, but are not limited to, polyphenylenes, phenolic resins, phenoxy resins, polysulfide ethers, polyphenylene sulfides, polyethersulfones, polyimines, polyetherimines, polyazoles, polybenzimidazoles, polybenzoxazoles, polybenzothiazoles, polybenzoxadiazoles, polybenzotriazoles, polyphosphazenes, polyetherketones, polyketones, polyetheretherketones, polyetherketone ketones, polyphenyleneamides,
  • Polyphenyleneoxide, polyimides and mixtures of two or more of these polymers are produced.
  • the polyimides also include polymers which in addition to imide also amide (polyamide), ester (polyester) u. Ether groups (polyetherimides) as
  • the various layers can be bonded together using suitable polymers. These include in particular fluoropolymers. Suitable fluoropolymers are known in the art. These include polyfluorotetraethylene (PTFE) and poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP).
  • PTFE polyfluorotetraethylene
  • FEP poly (tetrafluoroethylene-co-hexafluoropropylene)
  • the layer of fluoropolymers present on the layers described above generally has a thickness of at least 0.5 ⁇ m, in particular of at least 2.5 ⁇ m. This layer may be provided between the polymer electrolyte membrane and further layers.
  • the layer can also be applied to the side facing away from the polymer electrolyte membrane side.
  • both surfaces of the layers to be laminated may be provided with a layer of fluoropolymers. This can surprisingly improve the long-term stability of the MEUs.
  • At least one component of the outer region of the polymer electrolyte membrane is commonly in contact with electrically conductive separator plates, typically provided with flow field troughs on the sides facing the gas diffusion layers, to facilitate the distribution of reactant fluids.
  • the separator plates are usually made of graphite or of conductive, heat-resistant plastic.
  • the components of the outer area In combination with the separator plates, the components of the outer area generally seal the gas spaces to the outside.
  • the dense Components of the outer region in interaction with the inner region of the polymer electrolyte membrane generally also the gas spaces between anode and cathode.
  • the preparation of the membrane-electrode assembly according to the invention will be apparent to those skilled in the art.
  • the various components of the membrane-electrode assembly are superimposed and bonded together by pressure and temperature.
  • a temperature in the range of 10 to 300 ° C, in particular 20 ° C to 200 ° and at a pressure in the range of 1 to 1000 bar, in particular from 3 to 300 bar laminated.
  • the outer region of the polymer electrolyte membrane can be thickened by a second polymer layer.
  • This second layer can be laminated, for example.
  • the second layer can also be applied by thermoplastic methods, for example by extrusion or injection molding.
  • the finished membrane-electrode unit (MEU) is ready for operation after cooling and can be used in a fuel cell.
  • individual fuel cells according to the invention can be stored or shipped without problems due to their dimensional stability under fluctuating ambient temperatures and air humidity. Even after prolonged storage or after shipment to places with significantly different climatic conditions, the dimensions of the single fuel cells are perfectly suited for installation in fuel cell stacks. The single fuel cell then no longer needs to be conditioned on-site for external installation, which simplifies fuel cell manufacturing and saves time and money.
  • An advantage of preferred single fuel cells is that they allow the operation of the fuel cell at temperatures above 120 0 C. This applies to gaseous and liquid fuels, such as hydrogen-containing gases, which are prepared for example in an upstream reforming step from hydrocarbons. For example, oxygen or air can be used as the oxidant.
  • gaseous and liquid fuels such as hydrogen-containing gases
  • oxygen or air can be used as the oxidant.
  • Another advantage of preferred single fuel cells is that they have a high tolerance to carbon monoxide in operation above 120 0 C with pure platinum catalysts, ie without a further alloying ingredient. At temperatures of 160 ° C., for example, more than 1% of CO can be contained in the fuel gas, without this leading to a noticeable reduction in the power of the fuel cell.
  • Preferred single fuel cells can be operated in fuel cells without the need to humidify the fuel gases and oxidants despite the possible high operating temperatures.
  • the fuel cell is still stable and the membrane does not lose its conductivity. This simplifies the entire fuel cell system and brings additional cost savings, since the management of the water cycle is simplified. Furthermore, this also improves the behavior at temperatures below 0 ° C. of the fuel cell system.
  • Preferred single fuel cells allow surprisingly that the fuel cell can be cooled to room temperature and below without any problems and then put back into operation without losing power.
  • conventional phosphoric acid-based fuel cells sometimes have to be maintained at a temperature above 40 ° C., even when the fuel cell system is switched off, in order to avoid irreversible damage.
  • the preferred single fuel cells of the present invention exhibit very high long-term stability. It has been found that a fuel cell according to the invention can be operated continuously for long times, for example more than 5000 hours, at temperatures of more than 120 ° C. with dry reaction gases, without noticeable performance degradation being detectable. The achievable power densities are very high even after such a long time.
  • the fuel cells according to the invention even after a long time, for example more than 5000 hours, a high rest voltage, which is preferably at least 900 mV after this time.
  • a high rest voltage which is preferably at least 900 mV after this time.
  • Fuel cell is switched from a current of 0.2 A / cm 2 to the de-energized state and then recorded there for 5 minutes, the quiescent voltage.
  • the value after 5 minutes is the corresponding resting potential.
  • the measured values of the quiescent voltage apply for a temperature of 160 ° C.
  • the shows Fuel cell after this time preferably a low gas passage (gas cross-over).
  • the anode side of the fuel cell is operated with hydrogen (5 Uh), the cathode with nitrogen (5LVh).
  • the anode serves as a reference and counter electrode.
  • the cathode as a working electrode.
  • the cathode is set to a potential of 0.5 V and the diffusing through the membrane
  • the resulting current is a measure of the hydrogen permeation rate.
  • the current is ⁇ 3 mA / cm 2 , preferably ⁇ 2 mA / cm 2 , more preferably ⁇ 1 mA / cm 2 in a 50 cm 2 cell.
  • the measured values of H 2 cross-over are valid for a temperature of 160 ° C.
  • the fuel single cells according to the invention are characterized by improved temperature and corrosion resistance and a comparatively low gas permeability, especially at high temperatures. A decrease in the mechanical stability and the structural integrity, especially at high temperatures, according to the invention is best avoided.
  • the fuel single cells according to the invention can be produced inexpensively and easily.
  • Molecular weight determination was performed by static light scattering, the measurement being performed on a Multi-Angle Laser Diffusion Detector (MALLS) DAWN DSP Laser Photometer (Wyatt Technology Co.).
  • MALLS Multi-Angle Laser Diffusion Detector
  • DAWN DSP Laser Photometer
  • the device was equipped with an argon laser, which at a wavelength of 633 nm emitted and scattered between 30-130 ° angle.
  • the analysis was carried out at 25 ° C.
  • the specific refractive index increment was measured at 25 ° C with an Optilab 903 interferometric refractometer, and the refractive increment dn / dc was obtained by Wyatt software.
  • the measurement results were evaluated with ASTRA Software (Wyatt Corp.) using the Berry method based on the following formula:
  • V (Kc / R ⁇ ) (1 / V (M w )) + 2A 2 c
  • the stock solution for light scattering measurements had a concentration of 1x10 -3 g.mol -1 .
  • Each solution was cleaned prior to measurement using a filter material having a pore size of 0.2 mm and later filtered
  • the samples were dissolved in water (0.4 wt%) and measured at 25 ° C with a Ubelode viscometer.
  • a polyvinyl phosphonic acid was purchased from Polyscience.

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Abstract

L’invention concerne un polymère de poids moléculaire élevé, obtenu par un procédé selon lequel une composition est polymérisée radicalairement, ladite composition comprenant, par rapport à son poids total, au moins 80,0 % en poids de composés à insaturations éthyléniques, caractérisé en ce que la composition comprend au moins un monomère contenant des groupes acide phosphonique et/ou des groupes acide sulfonique. Le polymère présente un degré de polymérisation moyen en poids supérieur à 300 et est particulièrement approprié, en raison de ses propriétés chimiques et physiques, à une utilisation pour des membranes polymériques d’électrolyte (PEM) dans des piles à combustible à PEM.
EP06806596A 2005-10-31 2006-10-28 Ensembles membrane-electrodes ameliores et piles a combustible a duree de vie plus longue Withdrawn EP1955400A1 (fr)

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DE102005052378A DE102005052378A1 (de) 2005-10-31 2005-10-31 Verbesserte Membran-Elektrodeneinheiten und Brennstoffzellen mit hoher Lebensdauer
PCT/EP2006/010389 WO2007051570A1 (fr) 2005-10-31 2006-10-28 Ensembles membrane-electrodes ameliores et piles a combustible a duree de vie plus longue

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Families Citing this family (4)

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Publication number Priority date Publication date Assignee Title
WO2009124737A1 (fr) * 2008-04-11 2009-10-15 Basf Se Procédé d’exploitation d’une pile à combustible
CN104362200A (zh) * 2014-10-30 2015-02-18 广东爱康太阳能科技有限公司 一种高效晶硅太阳能电池及其制备方法
JP7075583B2 (ja) * 2018-03-26 2022-05-26 国立大学法人福井大学 ポリビニルホスホン酸の製造方法
CN109030585B (zh) * 2018-07-10 2020-12-15 泰州纳新新能源科技有限公司 一种提高工作环境安全性的检测方法

Family Cites Families (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4191618A (en) * 1977-12-23 1980-03-04 General Electric Company Production of halogens in an electrolysis cell with catalytic electrodes bonded to an ion transporting membrane and an oxygen depolarized cathode
US4212714A (en) * 1979-05-14 1980-07-15 General Electric Company Electrolysis of alkali metal halides in a three compartment cell with self-pressurized buffer compartment
US4333805A (en) * 1980-05-02 1982-06-08 General Electric Company Halogen evolution with improved anode catalyst
DE4330699A1 (de) * 1993-09-10 1995-03-16 Hoechst Ag Vinylsulfonsäure-Polymere
US5422411A (en) * 1993-09-21 1995-06-06 Ballard Power Systems Inc. Trifluorostyrene and substituted trifluorostyrene copolymeric compositions and ion-exchange membranes formed therefrom
US5525436A (en) * 1994-11-01 1996-06-11 Case Western Reserve University Proton conducting polymers used as membranes
DE19509749C2 (de) * 1995-03-17 1997-01-23 Deutsche Forsch Luft Raumfahrt Verfahren zur Herstellung eines Verbundes aus Elektrodenmaterial, Katalysatormaterial und einer Festelektrolytmembran
DE19509748C2 (de) * 1995-03-17 1997-01-23 Deutsche Forsch Luft Raumfahrt Verfahren zur Herstellung eines Verbundes aus Elektrodenmaterial, Katalysatormaterial und einer Festelektrolytmembran
DE19544323A1 (de) * 1995-11-28 1997-06-05 Magnet Motor Gmbh Gasdiffusionselektrode für Polymerelektrolytmembran-Brennstoffzellen
US6110616A (en) * 1998-01-30 2000-08-29 Dais-Analytic Corporation Ion-conducting membrane for fuel cell
JP3627586B2 (ja) * 1999-09-03 2005-03-09 日本ゼオン株式会社 リチウムイオン二次電池電極用バインダー、およびその利用
DE60029731T8 (de) * 1999-11-29 2007-11-08 Kabushiki Kaisha Toyota Chuo Kenkyusho Fester Polymerelektrolyt mit hoher Dauerhaftigkeit
DE19959289A1 (de) * 1999-12-09 2001-06-13 Axiva Gmbh Verfahren zur Herstellung von sulfonierten aromatischen Polymeren und Verwendung der Verfahrensprodukte zur Herstellung von Membranen
DE10110752A1 (de) * 2001-03-07 2002-09-19 Celanese Ventures Gmbh Verfahren zur Herstellung einer Membran aus verbrücktem Polymer und Brennstoffzelle
DE10129458A1 (de) * 2001-06-19 2003-01-02 Celanese Ventures Gmbh Verbesserte Polymerfolien auf Basis von Polyazolen
DE10140147A1 (de) * 2001-08-16 2003-03-06 Celanese Ventures Gmbh Verfahren zur Herstellung einer Blend-Membran aus verbrücktem Polymer und Brennstoffzelle
DE10144815A1 (de) * 2001-09-12 2003-03-27 Celanese Ventures Gmbh Protonenleitende Membran und deren Verwendung
ES2326871T3 (es) * 2002-03-01 2009-10-21 Daiichi Sankyo Company, Limited Inhibidores de sumoilacion.
DE10209419A1 (de) * 2002-03-05 2003-09-25 Celanese Ventures Gmbh Verfahren zur Herstellung einer Polymerelektrolytmembran und deren Anwendung in Brennstoffzellen
JP2005526875A (ja) * 2002-03-06 2005-09-08 ペメアス ゲゼルシャフト ミット ベシュレンクテル ハフツング ビニル含有スルホン酸を含む混合物、ポリビニルスルホン酸を含む高分子電解質膜、および燃料電池におけるその使用
DK1483316T3 (da) * 2002-03-06 2007-12-27 Pemeas Gmbh Protonledende elektrolytmembran med reduceret methanolpermeabilitet og anvendelse deraf til brændselsceller
DE10213540A1 (de) * 2002-03-06 2004-02-19 Celanese Ventures Gmbh Lösung aus Vinylphosphonsäure, Verfahren zur Herstellung einer Polymerelektrolytmembran aus Polyvinylphosphaonsäure und deren Anwendung in Brennstoffzellen
US20050118478A1 (en) * 2002-03-06 2005-06-02 Joachim Kiefer Mixture comprising sulphonic acid containing vinyl, polymer electrolyte membrane comprising polyvinylsulphonic acid and the use thereof in fuel cells
DE10209685A1 (de) * 2002-03-06 2003-09-18 Celanese Ventures Gmbh Verfahren zur Herstellung einer Polymerelektrolytmembran und deren Anwendung in Brennstoffzellen
CN100355133C (zh) * 2002-03-07 2007-12-12 宇部兴产株式会社 电解质膜和使用它的固体高分子型燃料电池
KR20040104621A (ko) * 2002-04-25 2004-12-10 페메아스 게엠베하 다층 전해질막
DE10220817A1 (de) * 2002-05-10 2003-11-27 Celanese Ventures Gmbh Verfahren zur Herstellung einer gepfropften Polymerelektrolytmembran und deren Anwendung in Brennstoffzellen
DE10220818A1 (de) * 2002-05-10 2003-11-20 Celanese Ventures Gmbh Verfahren zur Herstellung einer gepfropften Polymerelektrolytmembran und deren Anwendung in Brennstoffzellen
DE10230477A1 (de) * 2002-07-06 2004-01-15 Celanese Ventures Gmbh Funktionalisierte Polyazole, Verfahren zu ihrer Herstellung sowie ihre Verwendung
CA2494530A1 (fr) * 2002-08-02 2004-02-19 Pemeas Gmbh Membrane polymere conductrice de protons comprenant des polymeres a groupes acide sulfonique et application de ladite membrane dans des piles a combustible
DE10239701A1 (de) * 2002-08-29 2004-03-11 Celanese Ventures Gmbh Polymerfolie auf Basis von Polyazolen und deren Verwendung
DE10246373A1 (de) * 2002-10-04 2004-04-15 Celanese Ventures Gmbh Protonenleitende Polymermembran umfassend Sulfonsäuregruppen enthaltende Polyazole und deren Anwendung in Brennstoffzellen
DE10246459A1 (de) * 2002-10-04 2004-04-15 Celanese Ventures Gmbh Protonenleitende Polymermembran umfassend Phosphonsäuregruppen enthaltende Polyazole und deren Anwendung in Brennstoffzellen
US7834131B2 (en) * 2003-07-11 2010-11-16 Basf Fuel Cell Gmbh Asymmetric polymer film, method for the production and utilization thereof
WO2005011039A2 (fr) * 2003-07-27 2005-02-03 Pemeas Gmbh Membrane a conduction de protons et utilisation correspondante
JP3896105B2 (ja) * 2003-08-28 2007-03-22 株式会社東芝 燃料電池用電解質膜、及び燃料電池
US20080038624A1 (en) * 2003-09-04 2008-02-14 Jorg Belack Proton-conducting polymer membrane coated with a catalyst layer, said polymer membrane comprising phosphonic acid polymers, membrane/electrode unit and use thereof in fuel cells
DE10340927A1 (de) * 2003-09-04 2005-03-31 Celanese Ventures Gmbh Protonenleitende Polymermembran enthaltend Polymere mit an aromatische Gruppen kovalent gebundene Sulfonsäuregruppen, Membran-Elektoden-Einheit und deren Anwendung in Brennstoffzellen
DE10340928A1 (de) * 2003-09-04 2005-04-07 Celanese Ventures Gmbh Mit einer Katalysatorschicht beschichtete protonenleitende Polymermembran enthaltend Phosphonensäuregruppen umfassende Polymere, Membran-Elektroden-Einheit und deren Anwendung in Brennstoffzellen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2007051570A1 *

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KR20080063353A (ko) 2008-07-03
JP2009513756A (ja) 2009-04-02
US20090098430A1 (en) 2009-04-16
RU2008121760A (ru) 2009-12-10
CN101300708B (zh) 2010-12-29
WO2007051570A1 (fr) 2007-05-10
CA2627168A1 (fr) 2007-05-10
DE102005052378A1 (de) 2007-05-03
CN101300708A (zh) 2008-11-05

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