Surface graphitized carbon material, process for producing the same and negative electrode for lithium-ion secondary battery using the carbon material

摘要

A surface graphitized carbon material comprising a graphitic surface and a carbonaceous internal part. This surface graphitized carbon material can be produced by contacting a carbon material with a metal having catalytically graphitizing activity or a compound thereof to thereby cause the metal or compound thereof to be present in a surface of the carbon material and heating the carbon material at 300 to 1500C in an inert atmosphere. By virtue of the possession of a graphitic surface and a carbonaceous internal part, the surface graphitized carbon material of the present invention simultaneously has the properties of the carbon material such that, when used in a negative electrode for lithium-ion secondary battery, a negative electrode having high charge and discharge capacities, being excellent in performance at low temperature and facilitating a display of residual capacity can be obtained, and the properties of the graphite material such that a negative electrode whose cycle deterioration of charge and discharge capacities is slight can be obtained.