METHOD FOR PRODUCING POLYELECTROLYTE MEMBRANE, POLYELECTROLYTE MEMBRANE, MEMBRANE-ELECTRODE ASSEMBLY, AND FUEL CELL

摘要

PPROBLEM TO BE SOLVED: To provide a method for producing a polyelectrolyte membrane which achieves both of a methanol barrier property and proton conductivity at high levels inexpensively, provide the polyelectrolyte membrane obtained by the producing method, and provide a membrane-electrode assembly and fuel cell using the polyelectrolyte membrane. PSOLUTION: A process includes a membrane forming step of forming a membrane from a polyelectrolyte solution containing a hydrocarbon block-type polyelectrolyte and a solvent to produce a solvent-containing block-type polyelectrolyte membrane, and a heat treatment step of heating the solvent-containing block-type polyelectrolyte membrane. By using this process, the polyelectrolyte membrane with excellent characteristics for a direct methanol fuel cell is obtained, wherein a temperature of the heat treatment is a temperature higher than a heat decomposition start temperature of the block-type polyelectrolyte for structuring the solvent-containing block-type polyelectrolyte membrane, and a residual amount of the solvent in the polyelectrolyte membrane after the heat treatment is not less than 1 wt.%. PCOPYRIGHT: (C)2010,JPO&INPIT