| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative electrode material of graphite series for a lithium secondary battery excellent in the battery characteristics represented by the discharge capacity and the initial period efficiency and the powder characteristic. SOLUTION: A powder of graphite material (1-50μm) such as kish graphite, natural graphite, etc., in which turning into graphite is well grown where d002 is 0.3360 nm or less and Lc is 50 nm or more is included 1-40 wt.% in a coal series heavy oil or petroleum series heavy oil containing quinoline unsolved portion of 10 wt.% or less, followed by delayed caulking to produce a crude coke, and this is crushed into particles having a mean diameter of 20-30μm, and they are subjected to a heat treatment at 700-1500°C or a processing at 2600°C or more under existence of boron compound or without it to be turned into graphite, and thus the intended lithium secondary battery negative electrode material is manufactured. COPYRIGHT: (C)2004,JPO |
