Patent ID: 7306876
Filing Date: 2007-12-11
Classification: H01M,Y02E,Y02P

Abstract:
1. A method for producing a membrane-electrode structure, comprising the steps of: applying a catalyst paste onto a sheet substrate, wherein the catalyst paste comprises an electron conducting material supporting a catalyst and an ion conducting material; drying the catalyst paste to form an electrode catalyst layer; thermally transferring said electrode catalyst layer onto each side of a polymer electrolyte membrane to form a laminated body, wherein said electrode catalyst layer is connected to each side of said polymer electrolyte membrane; applying a first slurry onto a carbon substrate layer, wherein the first slurry comprises a water-repellent material and an electron conducting material; drying the first slurry to form a water-repellent layer; applying a second slurry onto said water repellent layer, wherein the second slurry comprises an electron conducting material and an ion conducting material; drying the second slurry to form a hydrophilic layer, wherein a diffusion electrode consisting of said carbon substrate, said water-repellent layer and said hydrophilic layer is formed; positioning said diffusion electrode on said electrode catalyst layer of said laminated body via said hydrophilic layer; and pressing said laminated body and said diffusion electrode together under heating to integrate said laminated body and said diffusion electrode, wherein said hydrophilic layer and said electrode catalyst layer are formed using a ratio of a weight of said ion conducting material contained in said electrode catalyst layer to a weight of said ion conducting material in said hydrophilic layer that is set within a range of 1.0 to 1.4.