NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery in which high output characteristics and safety can be made compatible. SOLUTION: The nonaqueous electrolyte secondary battery includes a positive electrode in which lithium can be doped and dedoped electrochemically, a negative electrode in which lithium can be doped and dedoped electrochemically, and an electrolyte interposed between the positive electrode and the negative electrode. The ratio of a discharge capacity B at a time of 5C discharge against a discharge capacity A at a time of 0.2C discharge ((B/A)×100) is ≥80%. The electrolyte contains as a solvent at least one of fluoroethylene carbonate and difluoroethylene carbonate. COPYRIGHT: (C)2009,JPO&INPIT