ELECTROLYTE MULTILAYER MEMBRANE FOR SOLID POLYMER FUEL CELL, MEMBRANE-ELECTRODE ASSEMBLY, AND FUEL CELL

摘要

Disclosed is an electrolyte multilayer membrane for solid polymer fuel cells, which is characterized by being composed of at least two polymer electrolyte membranes arranged in layers. This electrolyte multilayer membrane for solid polymer fuel cells is also characterized in that at least one electrolyte membrane contains a polymer block (A) having an aromatic vinyl compound unit as a main repeating unit and a flexible polymer block (B), and the polymer block (A) contains a block copolymer (I) having an ion-conducting group. Also disclosed are a membrane-electrode assembly and a solid polymer fuel cell. The electrolyte multilayer membrane is economical and environmentally friendly, while having high ion conductivity and methanol barrier property. It is preferable for the electrolyte multilayer membrane that at least two constituent electrolyte membranes contain the block copolymer (I) and/or that at least one constituent electrolyte membrane has an ion exchange capacity of not less than 0.7 meq/g and at least one constituent electrolyte membrane has an ion exchange capacity of less than 0.7 meq/g.