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

摘要

Disclosed are: a solid polymer electrolyte membrane for a polymer electrolyte fuel cell, which has high mechanical strength even when the thickness of the membrane is reduced and the concentration of an ionic group in the membrane is increased for the purpose of reducing an electrical resistivity of the membrane and has excellent dimensional stability when the membrane absorbs water; and a membrane electrode assembly having high output and excellent durability. Specifically disclosed are: a solid polymer electrolyte membrane (15) which comprises a fluorine-containing proton conductive polymer (i) having a proton conductivity of 0.06 S/cm or more under the atmosphere of temperature of 80°C and relative humidity of 50% and (ii) having a repeating unit derived from a vinyl ether monomer having a mass per mole of an ionic group (an equivalent weight) of 400 or less and a repeating unit derived from a perfluoro monomer (excluding the vinyl ether monomer) and a fluorine-containing reinforcing material; and a membrane electrode assembly (10) comprising an anode (13), a cathode (14) and the solid polymer electrolyte membrane (15) provided between the anode (13) and the cathode (14).