Patent ID: 8129073

Claim:
A fuel cell comprising: a catalyst-coated membrane including an anode catalyst layer, a cathode catalyst layer, a polymer electrolyte membrane disposed between said anode catalyst layer and said cathode catalyst layer; an anode gas diffusion layer; a cathode gas diffusion layer; an anode separator; and a cathode separator, wherein said anode catalyst layer and said cathode catalyst layer comprise a hydrogen ion conductive polymer electrolyte and a catalyst-carrying carbon that includes a carbon powder and an electrode catalyst carried on said carbon powder, said anode gas diffusion layer is disposed outside said anode catalyst layer, and said cathode gas diffusion layer is disposed outside said cathode catalyst layer, said anode separator is disposed outside said anode gas diffusion layer, and said cathode separator is disposed outside said cathode gas diffusion layer, said anode separator has a gas flow path for supplying a fuel gas to said anode gas diffusion layer and said anode catalyst layer, said cathode separator has a gas flow path for supplying an oxidant gas to said cathode gas diffusion layer and said cathode catalyst layer, at least one of said anode catalyst layer and said cathode catalyst layer has a center area facing either said gas flow path for supplying the fuel gas or said gas flow path for supplying the oxidant gas, respectively, and a peripheral area around said center area, a thickness of said center area and a mass of said electrode catalyst per unit area of said center area are constant, and said peripheral area in the form of islands, and a thickness of said peripheral area and a mass of said electrode catalyst per unit area of said peripheral area decrease from an inner side toward an outer side.