PRODUCTION METHOD FOR SOLID POLYMER ELECTROLYTE MEMBRANE, SOLID POLYMER ELECTROLYTE MEMBRANE, AND FUEL CELL INCLUDING SOLID POLYMER ELECTROLYTE MEMBRANE

摘要

The performance of an electrolyte membrane (21) is improved by imparting aeolotropy to physical properties of the electrolyte membrane (21). A first state solid polymer electrolyte membrane (21) containing a polymer having an ion-exchange group is softened, melted or dissolved, whereby a second state solid polymer electrolyte membrane (21) is formed. Then, the second state solid polymer electrolyte membrane (21) is cooled, while a strong magnetic field is applied to the second state solid polymer electrolyte membrane (21) in a predetermined direction, whereby the second state solid polymer electrolyte membrane (21) is hardened or solidified. As a result, the ion-conductivity in a membrane thickness direction can be improved in a fluorinated electrolyte membrane, and swelling in the membrane surface direction can be suppressed in an aromatic hydrocarbon electrolyte membrane.