POLYMER ELECTROLYTE MEMBRANE AND SOLID POLYMER FUEL CELL, MEMBRANE-ELECTRODE ASSEMBLY, AND CATALYST-LAYER-PROVIDED ELECTROLYTE MEMBRANE USING SAME

摘要

The invention is to provide a polymer electrolyte composition excellent in practicality which has such an excellent chemical stability as to be able to withstand a strong oxidizing atmosphere during operation of a fuel cell and is capable of achieving excellent proton conductivity under a low-humidified condition and excellent mechanical strength and physical durability as well as a polymer electrolyte membrane, a membrane electrode assembly, and a polymer electrolyte fuel cell which use the polymer electrolyte composition. The polymer electrolyte membrane of the invention is a polymer electrolyte membrane that contains at least an ionic group-containing polymer electrolyte and a polyazole, which is a polymer electrolyte membrane in which a phase separation of 2 nm or larger in which the polyazole is a main component is not observed in transmission type electron microscopic observation.