Proton-conductive polymer electrolyte membrane, method of manufacturing the proton-conductive polymer electrolyte membrane, and membrane-electrode assembly and polymer electrolyte fuel cell using the proton-conductive polymer electrolyte membrane

摘要

A method of manufacturing a proton-conductive polymer electrolyte membrane using polyvinyl alcohol (PVA) as a base material and having excellent proton conductivity and methanol blocking properties is provided. The method includes: heat-treating a precursor membrane including PVA and a water-soluble polymer electrolyte having a proton conductive group to proceed crystallization of the PVA; and chemically crosslinking the heat-treated precursor membrane with a crosslinking agent reactive with the PVA, to form a polymer electrolyte membrane in which a crosslinked PVA is a base material and protons are conducted through the electrolyte retained in the base material. The content of a water-soluble polymer except the PVA and the water-soluble polymer electrolyte in the precursor membrane is in a weight ratio of less than 0.1 with respect to the PVA.