NEGATIVE ELECTRODE MATERIAL FOR LITHIUM SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a negative electrode material for a lithium secondary battery with a superior battery charge and discharge quantity and its efficiency and a repetition stability by using plural carbon powders with their different bonding state between carbon atoms or plural carbon powders with their different particle size and size distribution. SOLUTION: A negative electrode material for a secondary battery is formed by using two or more types of carbon powders with their different bonding state between carbon atoms and/or two types of carbon powders with its different particle size or particle size distribution. Two or more types of carbon powders with their bonding state between carbon atoms and with their equal particle size may be used. The bonding state of carbon atoms may be either of crystal system structure and non-crystalline structure. The carbon powders may be mixed with two or more types of powders of approx. 10μm or less in average particle size and of approx. 50μm or more. The carbon powders may be structured with two or more particle size peaks as a particle size distribution. This negative electrode material preferably forms the bonding state between carbons by means of burning process at approx. 700 to 3,000 deg.C.