Patent ID: 6723464
Filing Date: 2004-04-20
Classification: H01M,Y02E

Abstract:
A solid polymer electrolyte membrane-electrode assembly comprising an anode-side gas diffusion layer, an anode catalyst region, a solid polymer electrolyte membrane, a cathode catalyst region, and a cathode-side gas diffusion layer in a sequential arrangement, wherein either the anode catalyst region or the cathode catalyst region or both comprise:(a). at least two catalyst layers wherein one catalyst layer has a side attached to said solid polymer electrolyte membrane and another catalyst layer has a side attached to one of said cathode-side or anode-side gas diffusion layers, and wherein an interface between said two catalyst layers lies between the solid polymer electrolyte and said one of the gas diffusion layers; (b). wherein said catalyst layers each comprise at least one catalyst and at least one ion-conducting material; (c). wherein said at least one catalyst in each of said at least two catalyst layers comprise substantially the same material; and (d). wherein the ionomer concentration of said at least two catalyst layers is substantially the same.