SOLID POLYMER ELECTROLYTE MEMBRANE AND ITS MANUFACTURING METHOD AS WELL AS LIQUID COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide a solid polymer electrolyte membrane suitably used for a polymer electrolyte fuel cell excellent in durability and capable of stably generating power for a long period of time.SOLUTION: The solid polymer electrolyte membrane contains a polymer having a sulfonic acid group and at least one selected from vanadium ion with the number of the sulfonic acid group of 0.01 to 100% contained in the polymer and a vanadium compound. The solid polymer electrolyte membrane contains: a polymer having a sulfonic acid group; and at least one selected from vanadium ion and a vanadium compound. The electrolyte membrane has at least one selected from the vanadium ion and the vanadium compound of 0.001 to 10 mm mol/g based on the total of the polymer and at least one selected from the vanadium ion and vanadium compound.