Membrane electrode structure for polymer electrolyte fuel cell

摘要

A membrane electrode structure for a polymer electrolyte fuel cell capable of offering excellent power generation performance both in high humidity conditions and low humidity conditions. The membrane electrode structure for a polymer electrolyte fuel cell is composed of a solid polymer electrolyte membrane 2 having proton conductivity, a cathode electrode catalyst layer 3 , an anode electrode catalyst layer 4 and gas diffusion layers 5, 6 . The gas diffusion layers 5, 6 have through holes with a mean diameter of 15 to 45 mum and a specific surface area of 0.25 to 0.5 m²/g, and have a bulk density of 0.35 to 0.55 g/cm³. An intermediate layer 7 is provided between the cathode electrode catalyst layer 3 and the gas diffusion layer 5 , and the intermediate layer 7 has through holes with a diameter of 0.01 to 10 mum and a volume of 3.8 to 7.0 mul/cm². The intermediate layer 7 is made of a water-repellent resin containing conductive particles.