NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with stable performance even when used at high electric potential of positive electrode at 4.2 V or more, and with safety having high discharge capacity. SOLUTION: This nonaqueous electrolyte secondary battery to solve the problem has a positive electrode plate, a separator and a negative electrode. The battery is so constituted that the separator is a multi-layered film having a microporous structure in which at least two or more single-layered films are laminated, and that the single-layered film facing the positive electrode of the multi-layered film is a single-layered film made of a polypropylene.