Gas diffusion electrode, method for manufacturing gas diffusion electrode, membrane electrode assembly, and fuel cell

Abstract

A low-cost gas diffusion electrode is described that overcomes defects of conventional techniques, that achieves both dry-up resistance and flooding resistance, and that has satisfactory power generation performance, where the gas diffusion electrode includes a conductive porous substrate, and a microporous layer containing conductive fine particles and provided on at least one surface of the conductive porous substrate. The gas diffusion electrode has, based on the number of fine pores having an area of 0.25 μm2 or more that are observed in a cross section of the microporous layer in a thickness direction, a percentage of fine pores having a circularity of 0.5 or more of 50% or more and 100% or less.

Dependencies are inferred from the claim text.