| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery, which can maintain capacity at a high level even when charge and discharge are repeated with a large current, and is useful for a battery of a hybrid car. SOLUTION: The lithium secondary battery is formed of the negative electrode carbon material, which is formed of carbon material of which a graphitization degree P<SB>1</SB>obtained from 11 diffraction line intensity measured by using a CuKα ray is 0.3≤P<SB>1</SB>≤0.8. The carbon material may have a crystallite size with an approximate thickness Lc (004) of a crystallite of 10-80 nm in a c-axis direction, and an approximate thickness La (110) of a crystallite of 10-190 nm in an a-axis direction. The carbon material can be obtained by baking an easily-graphitized carbon precursor (especially an easily-graphitized carbon precursor crosslinked by crosslinking agent) at a temperature lower than a general graphitization treatment temperature, for example, at a temperature in the range of 1,700-2,500°C. COPYRIGHT: (C)2011,JPO&INPIT |
