The present disclosure provides a flow battery comprising a flexible lithium ion conductive film having durability against a highly reductive non-aqueous electrolyte liquid. The flow battery according to the present disclosure comprises a first non-aqueous electrolyte liquid, a first electrode, a second electrode, and a lithium ion conductive film. The first non-aqueous electrolyte liquid contains lithium ions and further biphenyl, phenanthrene, stilbene, triphenylene, anthracene, acenaphthene, acenaphthylene, fluorene, fluoranthene, o-terphenyl, m-terphenyl, or p-terphenyl. The lithium ion conductive film comprises a composite body. The composite body contains a lithium ion conductive polymer and polyvinylidene fluoride. The lithium ion conductive polymer includes an aromatic ring into which a lithium salt of an acidic group has been introduced. The lithium ion conductive polymer and the polyvinylidene fluoride have been mixed with each other homogeneously in the composite body.

(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.

A membrane electrode assembly for fuel cells includes a proton conducting membrane having a first side and a second side. The proton conducting membrane in turn includes a first polymer including cyclic polyether groups and a second polymer having sulfonic acid groups. The membrane electrode assembly further includes an anode disposed over the first side of the proton conducting layer and a cathode catalyst layer disposed over the second side of the proton conducting layer.

A membrane electrode assembly for fuel cells includes a proton conducting membrane having a first side and a second side. The proton conducting membrane in turn includes a first polymer including cyclic polyether groups and a second polymer having sulfonic acid groups. The membrane electrode assembly further includes an anode disposed over the first side of the proton conducting layer and a cathode catalyst layer disposed over the second side of the proton conducting layer.

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.

The present invention provides: a polymer electrolyte composition which can achieve excellent proton conductivity under slightly humidified conditions, excellent mechanical strength and excellent physical durability, has excellent practicality, and can be produced using a nitrogen-containing additive, wherein the nitrogen-containing additive can prevent the elution of the additive under a strongly acidic atmosphere during the operation of a fuel cell, has excellent chemical stability so as to tolerate a strongly acidic atmosphere, can be dissolved in various general-purpose organic solvents, has superior processability, can be mixed with an ionic-group-containing polymer, can prevent the occurrence of phase separation during the formation of a film, and can prevent the formation of an island-in-sea-like phase separation structure or the occurrence of bleeding out during the formation of a film; and a polymer electrolyte membrane, a membrane electrode assembly and a polymer electrolyte fuel cell, each of which is produced using the polymer electrolyte composition. The polymer electrolyte composition according to the present invention comprises at least an ionic-group-containing polymer (A) and a nitrogen-containing additive (B), said polymer electrolyte composition being characterized in that the nitrogen-containing additive (B) is represented by a specific structural formula.

The present invention provides: a polymer electrolyte composition which can achieve excellent proton conductivity under slightly humidified conditions, excellent mechanical strength and excellent physical durability, has excellent practicality, and can be produced using a nitrogen-containing additive, wherein the nitrogen-containing additive can prevent the elution of the additive under a strongly acidic atmosphere during the operation of a fuel cell, has excellent chemical stability so as to tolerate a strongly acidic atmosphere, can be dissolved in various general-purpose organic solvents, has superior processability, can be mixed with an ionic-group-containing polymer, can prevent the occurrence of phase separation during the formation of a film, and can prevent the formation of an island-in-sea-like phase separation structure or the occurrence of bleeding out during the formation of a film; and a polymer electrolyte membrane, a membrane electrode assembly and a polymer electrolyte fuel cell, each of which is produced using the polymer electrolyte composition. The polymer electrolyte composition according to the present invention comprises at least an ionic-group-containing polymer (A) and a nitrogen-containing additive (B), said polymer electrolyte composition being characterized in that the nitrogen-containing additive (B) is represented by a specific structural formula.

The present invention relates to a composition for fuel cell membranes and a process for the preparation thereof. In particular, the present invention relates to thermo-mechanically and chemically stable polymer electrolyte membranes which have been prepared without compromising proton conductivity by using multifunctional polydopamine and mechanically robust nanocellulose.

The present invention relates to a composition for fuel cell membranes and a process for the preparation thereof. In particular, the present invention relates to thermo-mechanically and chemically stable polymer electrolyte membranes which have been prepared without compromising proton conductivity by using multifunctional polydopamine and mechanically robust nanocellulose.