Patent ID: 8211558

Claim:
A crosslinked polymer electrolyte obtained by the following (1) or (2): (1) reacting a compound having two or three or more reactive groups with a polymer electrolyte, or (2) reacting a compound having two or three or more reactive groups with a polymer to obtain a crosslinked polymer, and introducing an ion exchange group into the resultant crosslinked polymer; wherein the compound having two or three or more reactive n groups is at least one compound selected from the group consisting of the following formulae (i-1) to (i-5): wherein, in formulae (i-1) to (i-5), V represents a reactive group, and W represents a hydrogen atom, a substituent or a reactive group; in each formula, a plurality of Vs may be the same or different from each other; in each formula, a plurality of Ws may be the same or different from each other; and U represents direct bond or a divalent group; and wherein the polymer electrolyte includes a block copolymer having one or more blocks into which a sulfonic acid group is introduced and one or more blocks into which a sulfonic acid group is not substantially introduced, and at least one block of all the blocks has an aromatic ring in the main chain thereof.