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

摘要

The membrane-electrode assembly (26) is provided with: a polymer electrolyte membrane (32); catalyst layers (38, 42) disposed on the polymer electrolyte membrane; and gas diffusion layers (40, 44) disposed on the catalyst layers. The gas diffusion layers are composed of a porous member having electrically conductive particles and a polymer resin as the principal components. The ratio (y/x) of the tensile strength y (N/cm) of the gas diffusion layers and the rate of wet-to-dry dimensional change x (%) of the polymer electrolyte membrane is 0.10 or greater.