SOLID POLYMER ELECTROLYTE MEMBRANE FOR POLYMER ELECTROLYTE FUEL CELL AND MEMBRANE ELECTRODE ASSEMBLY

摘要

To provide a polymer electrolyte membrane for polymer electrolyte fuel cells, which is less likely to be broken even when it undergoes repetition of swelling in a wet state and shrinkage in a dry state; and a membrane/electrode assembly using it. A polymer electrolyte membrane 15 having a tensile yield stress of at most 5.5 MPa obtained by an evaluation method according to JIS K 7161-1994 from the tensile stress-strain curve obtained in accordance with the tensile test according to JIS K 7161-1994 at a temperature of 80°C at a strain rate of 1/min; and a membrane/electrode assembly 10 having the polymer electrolyte membrane 15 disposed between an anode 13 and a cathode 14 having a catalyst layer 11.