Patent attributes
An inexpensive and durable polymer electrolyte composition exhibiting high ionic conductivity even in the absence of water or a solvent, characterized by comprising a molten salt and an aromatic polymer having a carbonyl bond and/or a sulfonyl bond in the main chain thereof and containing a cation exchange group. The aromatic polymer is preferably an aromatic polyether sulfone having a specific structural unit and containing a cation exchange group, an aromatic polyether ketone having a specific structural unit and containing a cation exchange group, or an aromatic polyether sulfone block copolymer and/or an aromatic polyether ketone block copolymer, the block copolymers comprising a hydrophilic segment containing a cation exchange group and a cation exchange group-free hydrophobic segment. The polymer electrolyte composition containing the block copolymer as an aromatic polymer exhibits high structural retention even in high temperatures.