| 摘要 |
PROBLEM TO BE SOLVED: To improve safety and a charge/discharge cycle characteristic of a battery by charging a nonaqueous electrolyte secondary battery using a carbonaceous material as a negative electrode material with a charging current by regulating electric current density of a positive/negative electrodes opposing part to a specific value or less. SOLUTION: A transition metal composite oxide containing lithium is used as a positive electrode material of a battery. A carbonaceous material into/from which lithium can be electrochemically intercalated/ deintercalated and on which spacing of a (002) surface by a powder X ray wide angle diffraction method is not more than 3.42 Å, is used as a negative electrode material. When this battery is charged, a charging current is regulated to 3 mA/cm or less as electric current density of a positive/negative electrode opposed part, and constant current charge is performed. Or a maximum electric current is regulated to the electric current density or less, and constant voltage charge is performed. Therefore, at rapid charge time, a phenomenon of partially depositing on a negative electrode as needle-like lithium cannot be seen, and capacitive reduction caused by a cycle or the occurrence of an internal short circuit are eliminated. |
