| abstract |
(57) [Summary] (Modified) [PROBLEMS] To provide an energy storage medium having both high capacity and high cycle characteristics. SOLUTION: N having a structural unit represented by the formula (1) Using an electrode comprising a material containing an oxidized poly (N-containing fused heterocycle) polymer, an electrolyte containing an anion containing an S atom, and an electrolyte containing a cation serving as a counter ion thereof; Energy storage medium. (Any two of a to h represent at least one C atom participating in a bond between repeating units, an N → O group, and the rest represent a C atom, CH group, N atom or N → O group, The polymerization degree n is represented by at least 5, and R 1 and R 2 are each independently an H atom, It represents a halogen atom, a hydroxyl group, a carboxyl group, a sulfone group, a sulfate group, a nitro group, a cyano group, an alkyl group, an aryl group, an alkoxyl group, an amino group, an alkylthio group, an arylthio group, and the like. ) |