Patent ID: 6933067
Filing Date: 2005-08-23
Classification: H01M,Y02E

Abstract:
1. A polymer electrolyte fuel cell comprising: an electrode including a catalyst layer and a diffusion layer, said catalyst layer being sectioned into a plurality of portions including an upstream portion and a downstream portion along a reactant gas flow direction, wherein a structure of said catalyst layer differs between at said upstream portion and at said downstream portion, said upstream portion of said catalyst layer having a structure for preventing a drying-up of said cell, said downstream portion of said catalyst layer having a structure for preventing a flooding of said cell; wherein said structure of said catalyst layer for preventing a drying-up of said cell at said upstream portion includes each of the following (1)-(4) structures: (1) said catalyst layer includes a coating of the same resin as an electrolyte as one of components of the catalyst layer, wherein a ratio in amount of the same resin as the electrolyte to all of the components of said catalyst layer is larger at said upstream portion than at any other portion of the catalyst layer; (2) said catalyst layer includes pores, wherein a pore size of said catalyst layer is smaller at said upstream portion than at any other portion of the catalyst layer; (3) said catalyst layer includes pores, wherein a pore amount of said catalyst layer is smaller at said upstream portion than at any other portion of the catalyst layer; and (4) a thickness of said catalyst layer is greater at said upstream portion than at any other portion of the catalyst layer; and wherein said structure of said catalyst layer for preventing a flooding of said cell at said downstream portion includes each of the following (1)-(4) structures: (1) said catalyst layer includes a coating of the same resin as an electrolyte as one of components of the catalyst layer, wherein a ratio in amount of the same resin as the electrolyte to all of the components of said catalyst layer is smaller at said downstream portion that any other portion of the catalyst layer; (2) said catalyst layer includes pores, wherein a pore size of said catalyst layer is larger at said downstream portion than at any other portion of the catalyst layer; (3) said catalyst layer includes pores, wherein a pore amount of said catalyst layer is larger at said downstream portion than at any other portion of the catalyst layer; and (4) a thickness of said catalyst layer is smaller at said downstream portion than at any other portion of the catalyst layer.