| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery ensuring current shutoff when overcharged, without decreasing its discharging capacity characteristic. SOLUTION: The lithium ion secondary battery comprises a positive electrode wherein lithium/transition metal compound oxide with lithium carbonate of 0 to less than 0.5 wt.% absorbed thereto and lithium/transition metal compound oxide with lithium carbonate of 0.5 to 5 wt.% absorbed thereto are mixed in a weight ratio of 70-98 to 30-2; a negative electrode, a nonaqueous electrolyte, and a current shutoff means for the inside of the battery, the means being actuated upon buildup of the internal pressure of the battery. Preferably, the lithium/transition metal compound oxide of the positive electrode are lithium/ cobalt compound oxide and the negative electrode is made of a carbonaceous material enabling lithium ions to be released and inserted. |
