Catalyst layer for solid polymer fuel cells, membrane electrode assembly, and solid polymer fuel cell

Abstract

The present invention provides a catalyst layer for solid polymer fuel cells, a membrane electrode assembly, and a solid polymer fuel cell that improve drainage properties and gas diffusion properties, suppress cracks in the catalyst layer, improve catalyst utilization efficiency, increases energy conversion efficiency at high output, and provide good durability. This catalyst layer for solid polymer fuel cells includes a catalyst 21, carbon particles 22, a polymer electrolyte 23, and a fibrous substance 24. The carbon particles 22 support the catalyst 21. The catalyst layer for solid polymer fuel cells has gaps 25 and the frequency of gaps 25 that have a cross-sectional area of at least 10,000 nm2 among gaps 25 observed in a cross-section in the thickness direction intersecting the surface of the catalyst layer for solid polymer fuel cells is 13%-20%.

Description

technical field

[0001] The present invention relates to a catalyst layer for a polymer fuel cell, a membrane electrode assembly, and a solid polymer fuel cell. Background technique

[0002] In recent years, fuel cells have attracted much attention as an effective solution to environmental and energy problems. A fuel cell refers to a battery that uses an oxidant such as oxygen to oxidize fuel such as hydrogen and converts the accompanying chemical energy into electrical energy.

[0003] Fuel cells can be classified into alkaline type, phosphoric acid type, polymer type, molten carbonate type, solid oxide type, etc. according to the type of electrolyte. Solid polymer fuel cells (PEFC) are expected to be applied to portable power sources, household power sources, and vehicle power sources due to their low-temperature operation, high output power density, and miniaturization and weight reduction.

[0004] A solid polymer fuel cell (PEFC) has a structure in which a polymer elec...

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