Membrane electrode assembly and fuel cell

Abstract

A membrane electrode assembly includes an solid polymer electrolyte membrane, an anode, and a cathode. The cathode has a stacked body of a catalyst layer and a gas diffusion layer. The catalyst layer has platinum-cobalt-supporting carbon particles and an ion conductor. The ratio (P2 / P1) of the pore volume P2 (ml / g) per gram of catalyst layer in a second micro-pore diameter, ranging from 0.1 µm to less than 1 µm, over the pore volume P1 per gram of catalyst layer in a first micro-pore diameter, ranging from 0.01 µm to less than 0.1 µm, is in a range of 3.8 to 8.3.

Description

technical field

[0001] The present invention relates to fuel cells that generate electricity through the electrochemical reaction of hydrogen and oxygen. Background technique

[0002] In recent years, fuel cells that have high energy conversion efficiency and do not generate harmful substances through power generation reactions have attracted attention. As one of such fuel cells, a solid polymer fuel cell operating at a low temperature of 100° C. or lower is known.

[0003] A solid polymer fuel cell has a basic structure in which a solid polymer membrane as an electrolyte membrane is disposed between a fuel electrode and an air electrode, and a hydrogen-containing fuel gas is supplied to the fuel electrode, and an oxygen-containing oxidant gas is supplied to the air electrode. A device that generates electricity by following an electrochemical reaction.

[0004] Fuel electrode: H 2 →2H + +2e - …(1)

[0005] Air electrode: 1 / 2O 2 +2H + +2e - →H 2 O...(2) ...

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