Proton-conductive polymer electrolyte membrane, and membrane-electrode assembly and polymer electrolyte fuel cell using the same

摘要

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).