Method of fabricating membrane electrode assembly and gas diffusion layer

Abstract

A method of fabricating a membrane electrode assembly, comprising: obtaining a mixture by mixing and kneading electrically conductive particles, a polymer resin, a surfactant, and a dispersion solvent (S1); obtaining a sheet-like mixture by rolling out and shaping the mixture (S2); obtaining a carbon sheet by heat-treating the sheet-like mixture at a first heat treatment temperature such that the surfactant and the dispersion solvent are removed from the sheet-like mixture (S3); obtaining a dispersion liquid by mixing electrically conductive particles, a polymer resin, a surfactant, and a dispersion solvent (S4); forming, on the carbon sheet, a dispersion liquid layer thinner than the carbon sheet by forming and drying a coating of the dispersion liquid on the carbon sheet (S5); obtaining a gas diffusion layer in which a carbon layer is formed on the carbon sheet, by heat-treating the carbon sheet on which the dispersion liquid layer is formed at a second heat treatment temperature lower than the first heat treatment temperature such that the surfactant and the dispersion solvent are removed from the dispersion liquid layer (S6); and stacking a catalyst layer and an electrolyte membrane in said order on the carbon layer (S7).

Dependencies are inferred from the claim text.