CARBON MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION SECONDARY BATTERIES, AND LITHIUM ION SECONDARY BATTERY

摘要

A carbon material for a lithium ion secondary battery according to the present invention is a carbon material for a lithium ion secondary battery. The carbon material for the lithium ion secondary battery contains a graphite as a major component of the carbon material and a hard carbon. When an amount of the graphite contained in the carbon material is defined as "A" [wt%] and an amount of the hard carbon contained in the carbon material is defined as "B" [wt%], "A" and "B" satisfy a relationship of 1.2 ‰¤ A/B ‰¤ 19 and the amount of the graphite contained in the carbon material is in the range of 55 to 95 wt%. This makes it possible to provide the carbon material for the lithium ion secondary battery, the negative electrode material for the lithium ion secondary battery and the lithium ion secondary battery, which can provide high charge-discharge capacity and superior charge-discharge efficiency in good balance. Further, the amount of the hard carbon contained in the carbon material is preferably in the range of 5 to 45 wt%.