Patent ID: 7476459

Claim:
A membrane electrode assembly for use in a fuel cell, said membrane electrode assembly comprising: first and second electrodes, wherein at least one of the first and second electrodes includes a catalyst layer formed of a catalyst material; a solid polymer electrolyte membrane interposed between said first and second electrodes, wherein the catalyst layer contacts a first surface of the solid polymer electrolyte membrane; an adhesive layer formed of an adhesive material, the adhesive layer adhering to the first surface of the solid polymer electrolyte membrane; and a mixture layer formed of the catalyst material and the adhesive material and having a predetermined thickness, the mixture layer contacting the first surface of the said polymer electrolyte membrane and being disposed between said electrode catalyst layer and said adhesive layer, wherein a peripheral surface of said electrode catalyst layer contacts a first peripheral surface of the said mixture layer, and a peripheral surface of said adhesive layer contacts a second peripheral surface of said mixture layer, wherein a density of the catalyst material decreases along the mixture layer from the first peripheral surface to the second peripheral surface of the mixture layer, and a density of the adhesive material increases along the mixture layer from the first peripheral surface to the second peripheral surface of the mixture layer.