Patent ID: 7407723
Filing Date: 2008-08-05
Classification: H01M,Y02E

Abstract:
1. A polymer electrolyte fuel cell comprising: a membrane-electrode assembly having a hydrogen ion conductive polymer electrolyte membrane, and an anode and a cathode sandwiching said polymer electrolyte membrane; and an anode side separator plate and a cathode side separator plate disposed to support said membrane-electrode assembly from both sides thereof, said anode and said cathode each having a gas diffusion layer and a catalyst layer contacting said polymer electrolyte membrane, wherein at least one of said anode side separator plate and said cathode side separator plate includes a main surface portion entirely contacting said gas diffusion layer and a peripheral edge portion surrounding said main surface portion, said peripheral edge portion being formed to be flat, said main surface portion has a convex shape protruding toward said gas diffusion layer side, and has a gas flow path for supplying a reactant gas to said anode or said cathode, a thickness of at least one of said anode side separator plate and said cathode side separator plate increases or decreases in proportion to the shapes of the said main surface portion's protrusions; the surface of said main surface portion is formed so that a cross section perpendicular to said main surface portion draws a curve, the center of said main surface portion being the highest and the height gradually decreases toward said peripheral edge portion, said curve has an inflection point; and an average thickness of said main surface portion is thicker than an average thickness of said peripheral edge portion, and a difference Δt between a thickness of the thickest portion of said main surface portion and an average thickness of said peripheral edge portion is 5-30 μm.