| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an active material for negative electrode for a lithium secondary battery with large capacity, excellent in charging/discharging efficiency and electrode plate manufacturing processability, advantageous in life and low temperature characteristics, and to provide a manufacturing method of the same. <P>SOLUTION: The active material for negative electrode contains a crystalline carbon core of which a Raman spectrum intensity ratio of an I(1360) plane to an I(1580) plane ranges between 0.01 and 0.45, and a semi-crystalline carbon shell coating the core having a turbo-stratic or half-onion ring structure, of which, a Raman spectrum intensity ratio of an I(1360) plane to an I(1580) plane ranges between 0.46 and 1.5. The highly crystalline carbon like natural graphite is formed into a ball shape, and afterwards, a primary grain having a graphite structure of random orientation on the surface is formed through a grain forming process of the ball-shaped powder and a fine grain powder. The active material for negative electrode is formed by covering a low crystalline carbon with the primary grain, and by forming the turbo-stratic or half-onion ring structure on the surface by applying a high temperature heat treatment. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
