| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbonaceous material suited for the negative electrode material of a lithium secondary battery, which does not cause decrease in cycle life time, stores lithium in large amounts, and allows manufacturing at low cost for a lithium secondary battery with a high capacity far exceeding theoretical capacity for LiC6 . SOLUTION: A carbonaceous material, crushed after carbonization and having blade-shaped layer defects, is graphitized by heat treatment at 2500 deg.C or higher. The graphite obtained has, at least on its surface, a closed structure formed by connecting the terminals of two carbon network layers together, since the pore width between the carbon network layers in a part of the closed structure is as large as 1.0 to 5.0 manometers and the closed structure has a carbon network structure having a greater defect than a six-membered carbon ring and can therefore store a large amount of lithium therein, a lithium secondary battery with a high capacity exceeding 400Ah/kg can be fabricated. |
