Abstract: The present invention relates to a thermostable polymer electrolyte membrane which comprises a main chain comprising an alicyclic polybenzimidazole and a graft chain added to the main chain by radiation-induced graft polymerization, wherein at least a part of the graft chain has sulfonic acid groups. The thermostable polymer electrolyte membrane of the invention is used for many apparatuses such as polymer electrolyte fuel cells or water electrolysis devices, in which the electrolyte membrane exhibits high proton conductivity, low fuel permeability, high oxidation resistance and superior mechanical property under operation conditions at high temperature. The present invention also provides a simple and low-cost process for producing the same.

Abstract: A proton conducting copolymer electrolyte with competitive voltage versus current density characteristics and superior durability comprises a proton conducting hydrophilic domain comprising a sulfonated poly(phenylene) polymer, and a hydrophobic domain comprising a main chain comprising a plurality of bonded arylene groups wherein essentially all of the bonds in the main chain of the copolymer are carbon-carbon or, to a certain extent, carbon-sulfone bonds. More particularly, none of the bonds in the chains of the copolymer are ether bonds. Due to the absence of ether bonds, the copolymer electrolyte is less susceptible to degradation in solid polymer fuel cells.

Abstract: A novel method of altering extruded membrane films for PEM (polymer electrolyte membrane) fuel cells in such a manner that the membrane films swell substantially uniformly in both the in-plane x and y directions when immersed in water or ionomer solution is disclosed. The invention includes cutting a membrane film from an extruded membrane sheet in a diagonal orientation with respect to the membrane process direction of the membrane sheet. The membrane film exhibits reduced internal stress as compared to conventionally-prepared membrane films and allows a more even distribution of pressure in a fuel cell stack, thereby reducing the incidence of swollen membrane-induced failure mechanisms in the fuel cell stack.

Abstract: A polymer electrolyte membrane comprises at least one layer of a perforated sheet having many through-holes formed substantially parallel to the thickness direction with an average cross-sectional area per hole ranging from 1×10?3 to 20 mm2, wherein the numerical aperture based on the through-holes ranges from 30 to 80%, and the through-holes are filled with an ion exchange resin.

Abstract: Disclosed herein is a polyarylene-based polymer, a preparation method for the same, and a polymer electrolyte membrane for fuel cell using the polymer. The polyarylene-based polymer, which is designed to have long side chains of a hydrophilic moiety and dense sulfonic acid groups, may improve the formation of ion channels when fabricating a polymer membrane and also ensures good chemical stability of the hydrophilic moiety and good dimensional stability against water. Further, the preparation method of the present invention simplifies production of the polymer, and polymer electrolyte membranes using the polymer exhibits improved properties as a polymer electrolyte membrane for a fuel cell, such as high proton conductivity, even under an atmosphere of low water uptake, and good dimensional stability against a long-term exposure to water.

Abstract: An ion-conducting membrane for fuel cells includes an ion-conducting polymer having protogenic groups and poly(methyl methacrylate). Characteristically, the ion-conducting layer is planar having a thickness from 1 microns to 200 microns. A membrane electrode assembly includes the ion-conducting membrane interposed between a cathode layer and an anode layer.

Abstract: Provided is a varnish which contains a solvent and an electrode electrolyte for a solid polymer fuel cell electrolyte, which contains a polymer with a structure having a main chain including a polyphenylene, a side chain including a sulfonic acid group and a repeating structural unit as a side chain including a nitrogen-containing heterocyclic group.

Abstract: A composition showing enhanced proton conductivity comprising at least a polymer with an ionizable group (A) containing a proton and carbon nanostructures functionalized with ionizable group (B) containing a proton is disclosed where A and B are same or different.

Abstract: A polymer membrane composition for a fuel cell, a polymer membrane prepared therefrom, a membrane electrode assembly, a fuel cell including the same, and associated methods, the polymer membrane composition including a polymer, the polymer including a cation exchange group and a carbon double-bond-containing cross-linkable group, a (meth)acryl-based compound, the (meth)acryl-based compound including a cation exchange group, and a polymerization initiator.

Abstract: A polymer electrolyte membrane which exhibits superior high-temperature operability and a fuel cell and the like comprising the polymer electrolyte membrane are provided. In an aspect, the present invention relates to a polymer electrolyte membrane comprising a polymer electrolyte and having a first surface and a second surface, wherein the water vapor permeability coefficient from the first surface of the polymer electrolyte membrane to the second surface which is measured in a state where the first surface is exposed to a humidified environment of a temperature of 85° C. and a relative humidity of 20% and the second surface is exposed to a non-humidified environment of a temperature of 85° C. and a relative humidity of 0% is equal to or higher than 7.0×10?10 mol/sec/cm, and the breaking stress at a temperature of 80° C. and a relative humidity of 90% is equal to or greater than 20 MPa.

Abstract: A porous membrane with pores that includes a polymerization product of a polyazole-based material, an electrolyte membrane including the porous membrane with a proton-conductive polymer provided in pores of the porous membrane, methods of manufacturing the porous membrane and the electrolyte membrane, and a fuel cell employing at least one of the porous membrane and the electrolyte membrane.

Abstract: A vinyl monomer is graft polymerized on an aromatic hydrocarbon-based polymer film substrate to introduce graft chains into the substrate and thereafter a functional monomer represented by the following formula and having sulfonic acid groups or functional groups capable of conversion to sulfonic acid groups is graft polymerized to introduce the sulfonic acid groups or the functional groups capable of conversion to sulfonic acid groups: where R is an aromatic ring or an aliphatic chain; X is (1) —OH, (2) —OLi, —ONa or —OK, (3) —F or —Cl, or (4) —OCnH2n+1 where n is an integer of 1 to 7. Since the graft chains obtained by graft polymerization of the vinyl monomer can also be utilized as scaffold polymers, the graft polymerizability of the functional monomer to the aromatic hydrocarbon-based polymer film substrate is sufficiently improved to enable the preparation of a polymer electrolyte membrane that excels not only in proton conductivity and mechanical strength but also in dimensional stability.

Abstract: A fuel cell membrane electrode assembly is provided comprising a polymer electrolyte membrane which comprises a highly fluorinated polymer electrolyte and at least one cerium oxide compound dispersed therein. In addition, a method of making a fuel cell polymer electrolyte membrane is provided comprising the steps of: a) providing a highly fluorinated polymer electrolyte comprising acidic functional groups; b) dispersing therein at least one cerium oxide in an amount so as to provide between 0.01 and 5 percent of the total weight of the polymer electrolyte membrane; and c) thereafter forming a polymer electrolyte membrane comprising said polymer electrolyte.

Abstract: There is provided herein a dryer polymer substance including a hetero-phase polymer composition including two or more polymers wherein at least one of the two or more polymers include sulfonic groups, wherein the substance is adapted to pervaporate a fluid. The fluid may include water, water vapor or both. There is also provided herein a process for the preparation of a dryer polymer substance adapted to pervaporate a fluid (such as water, water vapor or both) the process includes mixing two or more polymers, wherein at least one of the two or more polymers may include groups which are adapted to be sulfonated, to produce a hetero-phase polymer composition and processing the polymer blend into a desired form.

Abstract: A fuel cell includes a first flow field plate defining at least one flow field channel. A cathode catalyst layer is disposed over at least a portion of the first flow field plate. A polymeric ion conducting membrane is disposed over cathode catalyst layer. An anode catalyst layer is disposed over the polymeric ion conducting membrane. Finally, a second flow field plate defining at least one flow field channel is disposed over the anode catalyst layer. The polymeric ion conducting membrane extends beyond the cathode catalyst layer and the anode catalyst layer such that the fuel cell has at least one peripheral region with the polymeric catalyst layer interposed between first flow field plate and the second flow field plate without the cathode catalyst layer and the anode catalyst layer.

Abstract: Disclosed herein is a proton-conducting polymer and uses thereof and, more particularly, a hydrocarbon-based proton-conducting polymer derived from a monomer having a multi-naphthyl group and comprising a plurality of acid groups on the side chain of the repeating unit, an electrolyte membrane comprising the polymer, a membrane-electrode assembly comprising the electrolyte membrane, and a fuel cell comprising the membrane-electrode assembly.

Abstract: A catalyst coated electrolyte membrane including an anode catalyst layer and a cathode catalyst layer at opposite sides thereof, respectively, wherein micro cracks of the anode catalyst layer or cathode catalyst layer occupy 0.01-1 area % of the total area of the respective anode catalyst layer or cathode catalyst layer, a fuel cell including the same, and a method of preparing the catalyst coated electrolyte membrane. In the catalyst coated electrolyte membrane, micro cracks of the cathode catalyst layer or the anode catalyst layer can be minimized and thus the resistance between the electrode catalyst layer and an electrolyte membrane can be minimized, and crossover of a fuel, such as methanol, ethanol, other alcohols, methane, etc., to a cathode electrode can be minimized, and thus the catalyst coated electrolyte membrane has improved performance and durability.

Abstract: A polymer represented by the following Formula 1, and a membrane-electrode assembly and a fuel cell system including the polymer: In the above Formula 1, definitions of the substituents are the same as in described in the detailed description.

Abstract: The invention relates to membrane-electrode assemblies for the electrolysis of water (electrolysis MEAs), which contain an ion-conducting membrane having a front and rear side; a first catalyst layer on the front side; a first gas diffusion layer on the front side; a second catalyst layer on the rear side, and a second gas diffusion layer on the rear side. The first gas diffusion layer has smaller planar dimensions than the ion-conducting membrane, whereas the second gas diffusion layer has essentially the same planar dimensions as the ion-conducting membrane (“semi-coextensive design”). The MEAs also comprise an unsupported free membrane surface that yields improved adhesion properties of the sealing material. The invention also relates to a method for producing the MEA products. Pressure-resistant, gastight and cost-effective membrane-electrode assemblies are obtained, that are used in PEM water electrolyzers, regenerative fuel cells or in other electrochemical devices.

Abstract: There are provided: a proton transporting material that improves mechanical characteristics of a sulfonated liquid crystalline polymer material, can be kept as a membrane even though it is made a solid state while maintaining a molecular arrangement of a liquid crystalline state, and is suitable for electrolyte membranes of fuel cells etc.; an ion exchange membrane, a membrane electrolyte assembly (MEA), and a fuel cell that use the proton transporting material; a starting material for the proton transporting material. The proton transporting material has a molecular structure produced by crosslinking the sulfonated liquid crystalline polymer material with a crosslinking agent having two or more functional groups in sites except that of the sulfonic acid group.

Abstract: The present invention relates to a sulfonated poly(arylene ether) copolymer, a manufacturing method thereof and a polymer electrolyte membrane for fuel cell using the same.

Abstract: Disclosed are processes for producing a fuel cell electrode and a membrane electrode assembly. In one preferred embodiment, the process comprises (a) preparing a suspension of catalyst particles dispersed in a liquid medium containing a polymer dissolved or dispersed therein; (b) dispensing the suspension onto a primary surface of a substrate selected from an electronically conductive catalyst-backing layer (gas diffuser plate) or a solid electrolyte membrane; and (c) removing the liquid medium to form the electrode that is connected to or integral with the substrate, wherein the polymer is both ion-conductive and electron-conductive with an electronic conductivity no less than 10?4 S/cm and ionic conductivity no less than 10?5 S/cm and the polymer forms a coating in physical contact with the catalyst particles or coated on the catalyst particles.

Abstract: A membrane-electrode junction agent, a proton conducting membrane having a junction layer, a membrane-electrode assembly, a polymer electrolyte fuel cell, and a manufacturing method of the membrane-electrode assembly, which enhance the power generation performance, realize the high fuel barrier property, and are capable of enhancing the joint strength between the membrane and the electrodes, is provided. A membrane-electrode junction agent that joins a proton conducting membrane and electrodes arranged on both surfaces of the proton conducting membrane to each other, the membrane-electrode junction agent including: a cross-linked compound (X) having a silicon-oxygen bond; a polymer material (Y) containing an acid group; and a hydrophilic resin (Z) containing no acid group.

Abstract: The present invention relates to block copolymer electrolyte composite membranes with improved ionic conductivity. The block copolymer electrolyte composite membrane in accordance with an aspect of the present invention can comprise a plate-like inorganic filler as surface-modified with a sulfonic group; and a block copolymer comprising at least one selected from the group consisting of a sulfonic group, a carbonic acid group, and a phosphoric acid group.

Abstract: The present invention provides a polymer electrolyte composition comprising a polymer electrolyte (A component) having an ion exchange capacity of from 0.5 to 3.0 meq/g, a compound (B component) having a thioether group and a compound (C component) having an azole ring, wherein a mass ratio (B/C) of the B component to the C component is 1/99 to 99/1, and a total content of the B component and C component is 0.01 to 50% by mass based on the solid content in the polymer electrolyte composition.

Abstract: The invention provides a method for producing a polymer electrolyte membrane including (A) a membrane formation step of forming a membrane-form product of an ionic group-containing polymer electrolyte on a support, (B) an acid treatment step of exchanging the ionic group into an acid type by bringing the membrane into contact with an inorganic acid-containing acidic liquid, (C) an acid removal step of removing a free acid in the acid-treated membrane, and (D) a drying step of drying the acid-removed membrane, wherein the steps (B) to (D) are carried out without separating the membrane from the support.

Abstract: A method of manufacturing a proton-conductive polymer electrolyte membrane using polyvinyl alcohol (PVA) as a base material and having excellent proton conductivity and methanol blocking properties is provided. The method includes: heat-treating a precursor membrane including PVA and a water-soluble polymer electrolyte having a proton conductive group to proceed crystallization of the PVA; and chemically crosslinking the heat-treated precursor membrane with a crosslinking agent reactive with the PVA, to form a polymer electrolyte membrane in which a crosslinked PVA is a base material and protons are conducted through the electrolyte retained in the base material. The content of a water-soluble polymer except the PVA and the water-soluble polymer electrolyte in the precursor membrane is in a weight ratio of less than 0.1 with respect to the PVA.

Abstract: A partially sulfonated polybenzimidazole based polymer for fuel cell membrane is prepared by copolymerizing monomers of 3,3?-diaminobenzidine, isophthalic acid and 5-sulfoisophthalic acid to obtain a partially sulfonated polybenzimidazole, and doping the partially sulfonated polybenzimidazole with inorganic acid.

Abstract: The present invention relates to a sulfonated poly(arylene ether) copolymer, a manufacturing method thereof and a polymer electrolyte membrane for fuel cell using the same.

Abstract: An object is to provide an electrolyte membrane that maintains excellent cell characteristics for a long time under high temperature and low water retention, as this is the most important point in fuel cells. A process for producing a polymer electrolyte membrane for fuel cells is provided, which process comprises in sequence: forming graft molecular chains by graft-polymerization of a vinyl silane coupling agent on a polymer film substrate that has phenyl groups capable of holding sulfonic acid groups; introducing sulfonic acid groups into phenyl groups contained in the graft molecular chains; and hydrolyzing and condensing alkoxy groups contained in the graft molecular chains so that a silane crosslinked structure is introduced between the graft molecular chains. A polymer electrolyte membrane produced by the process is also provided.

Abstract: An electrolytic membrane for a fuel cell including a crystalline organic and inorganic porous composite, an electrode for a fuel cell including a crystalline organic and inorganic porous composite, and a fuel cell including the electrolytic membrane and/or the electrode.

Abstract: A polymer electrolyte composition obtained by mixing a plurality of ion-conductive polymers, wherein if the ion-conductive polymer that is highest in ion exchange capacity among the plurality of ion-conductive polymers is termed first ion-conductive polymer, and the ion-conductive polymer that is lowest in ion exchange capacity is termed second ion-conductive polymer, then the first ion-conductive polymer and the second ion-conductive polymer are both block copolymers composed of a segment having an ion-exchange group and a segment having substantially no ion-exchange groups, and if the weight fraction of the segment having an ion-exchange group in the first ion-conductive polymer is termed Wh1, and the weight fraction of the segment having an ion-exchange group in the second ion-conductive polymer is termed Wh2, then the relations (I) and (II) listed below are satisfied: (I) Wh1>Wh2; (II) Wh1?Wh2?0.25.

Abstract: A membrane-electrode assembly for a solid polymer electrolyte fuel cell is provided that uses a proton conductive membrane having high proton conductivity and also superior heat resistance and chemical durability. A membrane-electrode assembly for a solid polymer electrolyte fuel cell is provided with an anode on one side of a proton conductive membrane and a cathode on another side thereof, and the proton conductive membrane is a sulfonated polyarylene containing a structure expressed by the general formula (1) below: —Rs—Z—Rh??(1) In the formula (1), Z represents at least one structure selected from the group consisting of —CO—, —SO2—, and —SO—; Rs represents a direct bond or any divalent organic group; and Rh represents a nitrogen-containing heterocyclic group.

Abstract: Polymer electrolyte membranes for use in fuel cells are produced by first graft polymerizing acrylic acid derivatives or vinylketone derivatives as monomers on polymer substrates and by then performing selective conversion to a sulfonic acid group of hydrogen atoms on the carbon atom adjacent to the carbonyl in the ketone or carboxyl group on the graft chains.

Abstract: A proton conducting polymer electrolyte comprising a proton conducting ionomer cross-linked with an amount of a copolymer additive comprising cross-linking functional groups and other functional groups (e.g. proton carriers, chelating agents, radical scavengers) shows improved durability over the ionomer alone and provides for more stable inclusion of these other functional groups. The copolymer additive comprises at least two types of metal oxide monomers, one having cross-linking functional groups and the other having the other functional groups.

Abstract: Additives can be used to prepare polymer electrolyte for membrane electrode assemblies in polymer electrolyte fuel cells in order to improve both durability and performance. The additives are chemical complexes comprising certain metal and organic ligand components.

Abstract: This invention relates to fuel cells, particularly proton exchange membrane fuel cells, more particularly to proton exchange membrane fuel cells employing nanocomposite sulphonated polystyrene-butadiene rubber-carbon nanoball (SPSBR-CNB) membranes as an electrolyte.

Abstract: In the present invention is disclosed a method for producing a membrane for direct liquid fuel cell, which comprises polymerizing and curing a polymerizable composition containing at least a) an aromatic polymerizable monomer wherein one polymerizable group, at least one hydrogen atom, and at least one substituent selected from the group consisting of methyl group bonded at the para-position relative to the polymerizable group, alkyl group having two or more carbon atoms, halogen atom, acyloxy group and alkoxy group are bonded to the aromatic ring, b) a crosslinkable polymerizable monomer, and c) a polymerization initiator, or impregnating the polymerizable composition into a porous membrane and polymerizing and curing the polymerizable composition, and then introducing a cation exchange group into the aromatic ring derived from the aromatic polymerizable monomer.

Abstract: Materials are provided that may be useful as ionomers or polymer ionomers, including compounds including bis sulfonyl imide groups which may be highly fluorinated and may be polymers.

Abstract: A polymer membrane for a fuel cell includes a porous polymer substrate, and a crosslinked polymer layer having a proton-conductive functional group coated on at least one side of the porous polymer substrate. A method of preparing the polymer membrane includes: (1) providing a coating composition that includes a monomer or a prepolymer having the proton-conductive functional group and a crosslinking catalyst; (2) coating the coating composition on the at least one side of the porous polymer substrate; and (3) crosslinking the monomer or the prepolymer coated on the porous polymer substrate.

Abstract: A fuel cell (100) includes a cation exchange membrane (110), a first anion exchange membrane (120) and a second anion exchange membrane (130). The cation exchange membrane (110) has a first side and an opposite second side. The first anion exchange membrane (120) has a first exterior surface and an opposite first interior surface disposed along at least a portion to the first side of the cation exchange membrane (110). A catalyst (140) is embedded along the first exterior surface. The second anion exchange membrane (130) has a second exterior surface and an opposite second interior surface disposed along at least a portion to the second side of the cation exchange membrane (110). A catalyst (142) is embedded along the second exterior surface. A stack of fuel cells (700) include a first fuel cell (701) with an acidic first anode (714) that is electrically coupled to an alkaline second cathode (722) of a second fuel cell (720).

Abstract: A polymer electrolyte composition of a sulfonated block copolymer (A) having a hydrophilic segment with a sulfonic acid group and a hydrophobic segment with no sulfonic acid group, each segment having an aromatic ring is its main chain, and an aromatic polymer (B) having no sulfonic acid group with a structural unit that is identical to the structural unit contained in the hydrophobic segment of the sulfonated block copolymer is provided. The ion-exchange capacity of the composition can be in a range of 0.5 mmol/g to 2.9 mmol/g. Electrolyte membranes, membrane/electrolyte assemblies, and electrolyte fuel cells utilizing the polymer electrolyte composition are also provide.

Abstract: This disclosure provides polymer electrolytes, polymer electrolyte membranes (PEM's) and membrane electrode assemblies (MEA's) such as may be useful in fuel cells which contain or comprise polyoxometalates (POM's) or heteropolyacids (HPA's). In some embodiments the polyoxometalate, it's counterions or both may comprise Mn and/or Ce. In some embodiments the polymer electrolyte is fluorinated. In some embodiments the polymer electrolyte comprises a second acidic functional group other than a polyoxometalate. In another aspect, the present disclosure provides methods of making polymer electrolytes including methods which comprising a step of copolymerizing monomers comprising a covalently bound polyoxometalates and methods which comprise a step of covalently attaching a polyoxometalate to the polymer.

Abstract: A solid polymer fuel cell stack has a layered product comprised of a plurality of cells stacked, and is so structured that the layered product is fastened by end plates on both sides thereof via a current collector and an insulating plate on each side. Each cell is structured such that an MEA is sandwiched between an anode-side plate, which is provided with a fuel path disposed counter to an anode of the MEA, and a cathode-side plate, which is provided with an oxidizing agent path disposed counter to a cathode of the MEA. An MEA is comprised of a solid polymer electrolyte membrane, an anode and a cathode. The solid polymer electrolyte membrane is composed of powder of basic polymer such as polybenzimidazole, strong acid such as phosphoric acid impregnated with the basic polymer, and binder such as fluorocarbon resin.

Abstract: A membrane electrode assembly (MEA) is structured such that an anode is joined, via a carbon layer, to one surface of a solid polymer electrolyte membrane containing PBI and phosphoric acid and a cathode is joined to the other surface. The carbon layer is constituted by carbon powder and a first binder. Carbon black, carbon nanotube and the like may be used as carbon powder. The thickness of the carbon layer is preferably greater than that of the solid polymer electrolyte membrane.

Abstract: A precursor electro-catalyst composition for producing a fuel cell electrode. The precursor composition comprises (a) a molecular metal precursor dissolved or dispersed in a liquid medium and (b) a polymer dissolved or dispersed in the liquid medium, wherein the polymer is both ion-conductive and electron-conductive with an electronic conductivity no less than 10?4 S/cm (preferably greater than 10?2 S/cm) and ionic conductivity no less than 10?5 S/cm (preferably greater than 10?3 S/cm). Also disclosed is an electro-catalyst composition derived from this precursor composition, wherein the molecular metal precursor is converted by heat and/or energy beam to form nanometer-scaled catalyst particles and the polymer forms a matrix that is in physical contact with the catalyst particles, coated on the catalyst particles, and/or surrounding the catalyst particles as a dispersing matrix with the catalyst particles dispersed therein when the liquid is removed.

Abstract: A polymer electrolyte membrane or gas diffusion electrode includes an ion-conducting polymeric material which includes moieties of formula (A) which are substituted on average with more than 1 and 3 or fewer groups (e.g. sulphonate groups) which provide ion-exchange sites and hydrogen atoms of said moieties are optionally substituted, wherein each X in said moieties of formula A independently represent an oxygen or sulphur atom. The ion conducting polymeric material is suitably prepared by controllably sulphonating a polymeric material using about 100% sulphuric acid at 34° C. to 36° C.

Abstract: Provided is a polyimide-based proton-conductive polymer electrolyte membrane having high methanol permeation resistance property (methanol blocking property). The proton-conductive polymer electrolyte membrane includes, as a main component, a polyimide resin formed by polycondensation of a tetracarboxylic dianhydride, a first aromatic diamine having a proton-conductive group, and a second aromatic diamine having no proton-conductive group. The second aromatic diamine has a fused ring skeleton composed of three or more rings. This electrolyte membrane is suitable for use in a polymer electrolyte fuel cell (PEFC), in particular in a direct methanol fuel cell (DMFC).

Abstract: Disclosed is a proton exchange membrane for use in fuel cells, which not only has improved proton conductivity and resistance to swelling caused by hot water but also has greater durability when used in a fuel cell, as well as a sulfonic acid group-containing segmented block copolymer constituting the proton exchange membrane, a membrane electrode assembly using the proton exchange membrane, and a fuel cell using the membrane electrode assembly. A sulfonic acid group-containing segmented block copolymer, which is a di- or multi-block copolymer including, within a molecule, at least one kind of hydrophilic segment and at least one kind of hydrophobic segment, a 0.5 g/dL solution thereof dissolved in N-methyl-2-pyrrolidone as a solvent showing a logarithmic viscosity measured at 30° C. in the range of 0.5 to 5.

Abstract: A high-performance solid polyelectrolyte film is provided which is produced by the radiation-induced graft polymerization method without causing solution gelation and which is excellent in mechanical strength, chemical stability, and dimensional stability and reduced in methanol permeability. According to the present invention, the solid polyelectrolyte film is produced by graft-polymerizing either a polymerizable monomer having an alkoxysilyl group alone or the polymerizable monomer having an alkoxysilyl group and another polymerizable monomer with a resin film which has been irradiated with a radiation, followed by hydrolyzing the alkoxysilyl groups to conduct dehydrating condensation. In addition, this solid polyelectrolyte film is disposed between a fuel electrode and an air electrode to fabricate a fuel cell.