Patent ID: 8999434
Filing Date: 2015-04-07
Classification: H01M,Y02E

Abstract:
1. A process for producing a membrane/electrode assembly comprising a first electrode having a first catalyst layer and a first gas diffusion layer, a second electrode having a second catalyst layer and a second gas diffusion layer, and an electrolyte membrane interposed between the first electrode and the second electrode, which comprises: applying a coating fluid comprising an ion exchange resin on a substrate, followed by annealing at from 100 to 250° C. to form an electrolyte membrane, and applying a coating fluid comprising an electrode catalyst and an ion exchange resin on the surface of the obtained electrolyte membrane to form the first catalyst layer, thereby to prepare a first intermediate consisting of said substrate, the electrolyte membrane and the first catalyst layer; applying a coating fluid comprising an electrode catalyst and an ion exchange resin on the surface of the second gas diffusion layer to form the second catalyst layer, thereby to prepare a second intermediate consisting of the second gas diffusion layer and the second catalyst layer; and bonding the first gas diffusion layer to the first intermediate, so that the first catalyst layer is located between the first gas diffusion layer and the electrolyte membrane, peeling said substrate from said first intermediate after bonding said first intermediate and said first gas diffusion layer, bonding said second intermediate to the electrolyte membrane so that said second catalyst layer is located between the second gas diffusion layer and the electrolyte membrane, and wherein the first gas diffusion layer comprises a gas-diffusing substrate and a first carbon layer formed on the surface of the gas-diffusing substrate by applying a coating fluid comprising a fluorinated ion exchange resin and carbon fiber having a fiber diameter of from 50 to 200 nm and a fiber length of from 1 to 50 μm, and the first gas diffusion layer and the first intermediate are bonded, so that the first carbon layer and the first catalyst layer are in contact with each other.