To provide a lithium ion secondary battery which is high in capacity and also excellent in charge/discharge cycle characteristics.
In a lithium ion secondary battery including a negative electrode and a positive electrode, the negative electrode comprises a negative electrode active material having an initial charge capacity of 1,800 mAh/g or more and an initial efficiency (initial discharge capacity/initial charge capacity) of 0.70-0.85, the positive electrode comprises a positive electrode active material having an initial charge capacity of 160 mAh/g or more and an initial efficiency (initial discharge capacity/initial charge capacity) of 0.75-0.90, and an initial discharge capacity ratio between the negative electrode and the positive electrode (initial discharge capacity of the negative electrode/initial discharge capacity of the positive electrode) is 0.90-1.30.
MIYAWAKI SATORU
IKEDA TATSUHIKO
| JP2000030693A | 2000-01-28 | |||
| JPH1145742A | 1999-02-16 |
| WO2012014998A1 | 2012-02-02 |