Lithium secondary battery

摘要

A lithium secondary battery with a large capacity and a long cycle life is disclosed. This lithium secondary battery includes a case (1), a negative electrode (6) accommodated in the case (1) and containing a poly-meric material which has been formed by heat-treating a polymer having a perynaphthalene structure as a main repeating unit in a non-oxidizing atmosphere at 500 to 1000 DEG C and which absorbs and desorbs lithium ions, a positive electrode (4) accommodated in the case (1) and so arranged as to oppose the negative electrode (6) with a separator (5) sandwiched between them, and a nonaqueous electrolyte contained in the case (1).