Patent ID: 6939646

Claim:
A polymer electrolyte having, in a main chain, a structural unit represented by the following formula (1): —(Ar 1 —(SO 2 —N − (X + )—SO 2 —Ar 2 ) m —SO 2 —N − (X + )—SO 2 —Ar 1 —O]— (1) and further comprising, in a main chain, a structural unit represented by the following formula (2): —[Ar 3 —O]— (2) wherein Ar 1 and Ar 2 independently represent a divalent aromatic groups, m represents an integer of 0 to 3, X + represents an ion selected from hydrogen ion, an alkali metal ion and ammonium ion and Ar 3 represents a divalent aromatic group.