MEMBRANE-ELECTRODE ASSEMBLY, FUEL CELL STACK, FUEL CELL SYSTEM, AND METHOD FOR OPERATION THEREOF

摘要

A membrane-electrode assembly (26) includes: a polymer electrolyte membrane (32); catalyst layers (38, 42) disposed on the polymer electrolyte membrane,; and gas diffusion layers (40, 44) respectively disposed on the catalyst layers. Each of the gas diffusion layers is constituted by a porous member containing electrically-conductive particles and polymer resin as major components, and a ratio (y/x) of a tensile strength y (N/cm) of the gas diffusion layer to a dry-wet size change rate x (%) of the polymer electrolyte membrane is 0.10 or higher.