| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbon negative electrode material for a lithium ion secondary battery having a large charging/discharging capacity. SOLUTION: A negative electrode active material is formed from carbon material meeting the condition that the carbon content is 94 wt.% or more and oxygen content is 5 wt.% or less, the d002 value obtained through X-ray diffraction is 0.38-0.45 nm, and that Vpore according to the following expression is 5-30; Vpore=(1-ρa/ρHe)×100, where ρa is the density measured by using water or ethanol as medium, and ρHe is the density measured by using helium gas as medium. With this carbon material, a secondary battery having a large discharging capacity can be manufactured. |
