▎ 摘　　要

NOVELTY - Manufacture of membrane-electrode assembly having a polymer electrolyte membrane interposed between a cathode and an anode involves forming a cathode by applying a electrode composition (C1) comprising an ionomer binder, a catalyst and a solvent to one surface of a polymer electrolyte membrane, and forming an anode by applying a electrode composition (C2) comprising an ionomer binder, a catalyst and a solvent to the other surface of the polymer electrolyte membrane. The binder is nano-dispersed ionomer binder under supercritical conditions in a mixed solvent containing alcohol and water. USE - Manufacture of membrane-electrode assembly for fuel cell and water electrolyzer (all claimed). ADVANTAGE - The method improves the electrochemical performance and durability of cells without developing a separate catalyst.