CARBON MATERIAL FOR NEGATIVE ELECTRODE OF LITHIUM SECONDARY BATTERY AND ACCELERATOR FOR GRAPHITIZATION

摘要

PROBLEM TO BE SOLVED: To provide a carbon material for a negative electrode which contributes to improve the performance of a lithium secondary battery and to provide an accelerator for the graphitization, which is suitable for producing the carbon material. SOLUTION: The accelerator for the graphitization is prepared from a boron carbide powder containing 0 to 3 wt.% Fe and 0 to 2 wt.% boron oxide. The carbon material for a negative electrode of the lithium secondary battery is composed of a carbon material obtained by adding the accelerator for the graphitization to a carbonaceous material and firing in a non-oxidizing atmosphere at a temp. of >=2,450 deg.C and has properties that Fe-content is not more than 0.3 wt.% and the content of the boron oxide can not be detected by the methanol titration method.