Patent ID: 7858668

Claim:
A method of manufacturing an electrolyte membrane formed of a cross-linked reaction product of a benzoxazine monomer with cross-linkable compound, the method comprising: dissolving the cross-linkable compound in a solvent to obtain a 10 to 20% by weight cross-linkable compound solution; mixing the cross-linkable compound solution and the benzoxazine monomer to obtain a mixture of the benzoxazine monomer and the cross-linkable compound; forming a membrane using the mixture; heating the membrane to perform thermal curing to a temperature of 80 to 250° C.; and impregnating the resultant obtained through the thermal curing with an acid to form an electrolyte membrane, wherein the cross-linkable compound comprises at least one compound selected from the group consisting of polybenzimidazole, polybenzthiazole and polybenzoxazole.