| 摘要 |
The present invention provides a membrane electrode assembly for use in a solid polymer electrolyte fuel cell which assembly can attain an excellent electric power generation performance both under low-humidity conditions and under high-humidity conditions. The membrane electrode assembly includes: a solid polymer electrolyte membrane 2 having proton conductivity; a cathode electrode catalyst layer 3 disposed on one side of the solid polymer electrolyte membrane 2; an anode electrode catalyst layer 4 disposed on the other side of the solid polymer electrolyte membrane 2; and two gas diffusion layers 5 and 6 disposed on a side of the cathode electrode catalyst layer 3 and a side of the anode electrode catalyst layer 4, respectively, both these sides facing away from the solid polymer electrolyte membrane 2; wherein the gas diffusion layer 6 in the anode side is smaller in contact angle to water than the gas diffusion layer 5 in the cathode side. The membrane electrode assembly also includes at least two coating layers 11 a and 11 b different in properties from each other between the gas diffusion layer 5 and the cathode electrode catalyst layer 3, and at least two coating layers 12 a and 12 b different in properties from each other between the gas diffusion layer 6 and the anode electrode catalyst layer 4.
|
