| 摘要 |
PROBLEM TO BE SOLVED: To produce graphite powder suitable as a cathode material for lithium secondary batteries high in discharge capacities and in charge and discharge efficiencies. SOLUTION: This graphite powder having a closed structure in which the terminals of the graphite (c) surface layers on the surface are closed in loop-like shapes, and having a space surface density of 100-1,500 spaces/μm in the graphite (c) axial direction and a crystallite diameter of 100-2,000Å is obtained by a method crushing a carbon material with a hammer crusher and a disk crusher and subsequently graphitizing the crushed carbon material at a temperature of >=2,500 deg.C, or by a method for crushing a carbon material with a disk crusher, graphitizing the crushed carbon material at a temperature of >=2,500 deg.C, and subsequently further subjecting the product to an oxidative thermal treatment and a thermal treatment at a temperature of >=800 deg.C in an inert gas. |
