METHOD FOR PRODUCING CATALYST INK FOR FUEL CELLS, METHOD FOR PRODUCING CATALYST LAYER FOR FUEL CELLS, AND METHOD FOR PRODUCING MEMBRANE ELECTRODE ASSEMBLY FOR FUEL CELLS

摘要

To make it easier to adjust the storage modulus of a gelled ionomer solution to 150 Pa or more. A method for producing a catalyst ink for fuel cells, which comprises: (i) a step wherein a catalyst dispersion liquid is prepared by mixing an electrode catalyst, water and an alcohol; (ii) a step wherein a gelled ionomer solution is prepared by mixing an ionomer and a solvent; and (iii) a step wherein a catalyst ink is produced by mixing the catalyst dispersion liquid and the gelled ionomer solution. The step (ii) includes a concentration step wherein the gelled ionomer solution is concentrated.