Patent ID: 9577276
Date: 2017-02-21
CPC Classifications: H01M,Y02E

Claim:
1. A fuel cell membrane electrode assembly, the membrane electrode assembly comprising: a solid polymer electrolyte membrane; a first electrode provided on one surface of the solid polymer electrolyte membrane, the first electrode including a first catalyst layer and a first gas diffusion layer; and a second electrode provided on another surface of the solid polymer electrolyte membrane, the second electrode including a second catalyst layer and a second gas diffusion layer, wherein: a surface size of the first gas diffusion layer is larger than a surface size of the second gas diffusion layer; a frame shaped protection member is formed around an outer marginal portion of the solid polymer electrolyte membrane extending outward beyond an outer end of the second gas diffusion layer; a cushioning member is provided between the outer marginal portion of the solid polymer electrolyte membrane and the protection member; the cushioning member comprising an inner portion and an outer portion extending from the inner portion; the cushioning member has an overlapped portion overlapped on an outer marginal end of the second gas diffusion layer; the inner portion of the cushioning member has the overlapped portion overlapped on the second catalyst layer; the outer portion is arranged in a stepped manner in relation to the inner portion; a thickness of the inner portion is substantially equal to a thickness of the outer portion; the cushioning member extends beyond an inner end of the frame shaped protection member toward a center of the solid polymer electrolyte membrane; and a thickness of the cushioning member is greater than a thickness of the second electrode catalyst layer by at least 10 μm.