A preparation method of composite materials having ion exchange function is provided. The method comprises the following steps: adding a trace of strong protonic acid and/or Lewis acid as a catalyst into the material during compounding, to allow nitrile groups of at least one nitrile group-containing ion exchange resin and nitrile groups of functional monomers grafted on the porous fluoropolymer membrane to form a triazine ring crosslinked structure.

An ion exchange membrane for a redox flow battery, the anion exchange membrane including a porous substrate; and a polymer disposed in the porous substrate, wherein the polymer is a polymerization product of a composition for forming the ion exchange membrane, wherein the composition includes a first monomer and a second monomer, wherein the first monomer is substituted with a group including an ethylenic unsaturated double bond and includes a cationic heterocyclic compound including a nitrogen heteroatom and a counter anion thereof, and wherein the second monomer is polymerizable with the first monomer and is at least one selected from a (meth)acrylamide compound and a (meth)acrylate compound.

An ion exchange membrane for a redox flow battery, the anion exchange membrane including a porous substrate; and a polymer disposed in the porous substrate, wherein the polymer is a polymerization product of a composition for forming the ion exchange membrane, wherein the composition includes a first monomer and a second monomer, wherein the first monomer is substituted with a group including an ethylenic unsaturated double bond and includes a cationic heterocyclic compound including a nitrogen heteroatom and a counter anion thereof, and wherein the second monomer is polymerizable with the first monomer and is at least one selected from a (meth)acrylamide compound and a (meth)acrylate compound.

(Problem) To provide an electrolyte film for fuel cells, capable of achieving both low resistance (film thinning) and high dimensional stability.

(Solution) An electrolyte film for fuel cells, the electrolyte film comprising a polymeric electrolyte and a polytetrafluoroethylene (PTFE) porous film, characterized in that a material having an elastic modulus higher than that of the material constituting the PTFE porous film is composited on the inside surfaces of pores of the PTFE porous film, and the composited PTFE porous film has an elastic modulus of at least 150 MPa.

Embodiments of the invention include fuel cells incorporating sheets and/or powders of silica fibers and methods for producing such devices. The silica fibers may be formed via electrospinning of a sol gel produced with a silicon alkoxide reagent, such as tetraethyl ortho silicate, alcohol solvent, and an acid catalyst.

An electrolyte membrane including (i) a porous mat of nanofibres, wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent; and (ii) an ion-conducting polymer which is a partially- or fully-fluorinated sulphonic acid polymer. The porous mat is essentially fully impregnated with ion-conducting polymer, and the thickness of the porous mat in the electrolyte membrane is distributed across at least 80% of the thickness of the electrolyte membrane. Such a membrane is of use in a proton exchange membrane fuel cell or an electrolyser.

An electrolyte membrane including (i) a porous mat of nanofibres, wherein the nanofibres are composed of a non-ionically conducting heterocyclic-based polymer, the heterocyclic-based polymer comprising basic functional groups and being soluble in organic solvent; and (ii) an ion-conducting polymer which is a partially- or fully-fluorinated sulphonic acid polymer. The porous mat is essentially fully impregnated with ion-conducting polymer, and the thickness of the porous mat in the electrolyte membrane is distributed across at least 80% of the thickness of the electrolyte membrane. Such a membrane is of use in a proton exchange membrane fuel cell or an electrolyser.

In this fuel cell electrode catalyst layer, a catalyst is supported on a carrier comprising inorganic oxide particles. The fuel cell electrode catalyst layer is provided with a porous structure. When a mercury penetration method is used to measure the pore size distribution of the porous structure, a peak is observed in the range spanning from 0.005 μm to 0.1 μm inclusive, and a peak is also observed in the range spanning from over 0.1 μm to not more than 1 μm. When P1 represents the peak intensity in the range spanning from 0.005 μm to 0.1 μm inclusive, and P2 represents the peak intensity in the range spanning from over 0.1 μm to not more than 1 μm, the value of P2/P1 is 0.2-10 inclusive. It is preferable that the inorganic oxide be tin oxide.

In this fuel cell electrode catalyst layer, a catalyst is supported on a carrier comprising inorganic oxide particles. The fuel cell electrode catalyst layer is provided with a porous structure. When a mercury penetration method is used to measure the pore size distribution of the porous structure, a peak is observed in the range spanning from 0.005 μm to 0.1 μm inclusive, and a peak is also observed in the range spanning from over 0.1 μm to not more than 1 μm. When P1 represents the peak intensity in the range spanning from 0.005 μm to 0.1 μm inclusive, and P2 represents the peak intensity in the range spanning from over 0.1 μm to not more than 1 μm, the value of P2/P1 is 0.2-10 inclusive. It is preferable that the inorganic oxide be tin oxide.

The present invention relates to a laminate comprising (i) an ion exchange membrane comprising an ion exchange polymer, and (ii) a monolayered release film removably adhered to at least one side of the ion exchange membrane, wherein the monolayered release film comprises at least 95% by weight of syndiotactic polystyrene (sPS). The invention also relates to a method for producing the laminate, use of the monolayered release film in producing an electrolyte membrane or a membrane electrode assembly, and a method for producing an electrolyte membrane or a membrane electrode assembly.