Patent ID: 8685588

Claim:
A membrane electrode assembly for use in a solid polymer electrolyte fuel cell, comprising: a membrane-electrode structure which includes a polymer electrolyte membrane, a first electrode layer provided on one side of said electrolyte membrane, a first gas diffusion layer provided on an opposite side of said first electrode layer from said electrolyte membrane, a second electrode layer provided on the other side of said electrolyte membrane, and a second gas diffusion layer provided on an opposite side of said second electrode layer from said electrolyte membrane; and a resin frame which is provided in such a manner as to fully enclose an outer periphery of said electrolyte membrane and to enclose at least portions of outer peripheries of said first and second gas diffusion layers, said resin frame being provided so as to enclose said electrolyte membrane side, and wherein said first gas diffusion layer and said first electrode layer are stacked on a surface of said electrolyte membrane so that the outer periphery of said first gas diffusion layer entirely lies within a boundary defined by the outer periphery of said electrolyte membrane and so that a surface region of said electrolyte membrane is left exposed between the outer periphery of said first electrode layer and the outer periphery of said electrolyte membrane, all around the outer periphery of said first electrode layer, said second gas diffusion layer extends as far as at least a portion on a side opposite from said surface region, all around the outer periphery of said electrolyte membrane, said resin frame is attached fixedly to at least a portion of said surface region, and wherein said electrolyte membrane comprises two membranes having different area sizes, and the membrane located on the side that contacts said first electrode layer has the same area size as said first gas diffusion layer and is aligned in precise registry with said first gas diffusion layer, while the membranes located on the side that contacts said second electrode layer has the same area size as said second gas diffusion layer and is aligned in precise registry with said second gas diffusion layer.