Patent ID: 7195838
Filing Date: 2007-03-27
Classification: H01M,Y02E

Abstract:
1. A membrane electrode assembly comprising: a solid polymer electrolyte membrane having two opposed surfaces, each surface being a single plane surface, wherein a thickness of the solid polymer electrolyte membrane is substantially uniform; a pair of gas diffusion electrode layers having catalyst layers and gas diffusion layers, and a bonding layer formed on an outer circumferential region of one of the catalyst layers of the pair of gas diffusion electrode layers covering the solid polymer electrolyte membrane, the bonding layer covering a peripheral region of the solid polymer electrolyte membrane, a border surface formed between the bonding layer and one of the catalyst layers being offset to a surface of an outer circumference of the other catalyst layer, wherein the catalyst layers of the gas diffusion electrode layers sandwich the solid polymer electrolyte membrane, one surface of the solid polymer electrolyte membrane is covered by one gas diffusion electrode layer and the other surface of the solid polymer electrolyte membrane extends over the other gas diffusion electrode layer, and ends of the catalyst layer of one gas diffusion electrode layer are disposed to be offset to ends of the catalyst layer of the other gas diffusion electrode layer.