Patent ID: 8637187

Claim:
A negative-electrode material for a lithium secondary battery, comprising a graphite powder (A) having a tap density of 0.8 g/cm 3 to 1.35 g/cm 3 , an amount of surface functional groups, O/C value, of 0 to 0.01, a ratio of volume-based 90% diameter to volume-based 10% diameter (d 90 /d 10 ) is 1.5 to 4.0, a BET specific surface area of 2.5 m 2 /g to 7.0 m 2 /g, and a Raman R value of 0.02 to 0.05, wherein the amount of surface functional groups, O/C value, is an atomic concentration ratio O/C (atomic concentration of O/atomic concentration of C) obtained from peak areas of spectra of C1s and O1s according to X-ray photoelectron spectroscopy, and the Raman R value is an intensity ratio R (R=I B /I A ) between the intensity I A of a peak P A of about 1580 cm −1 and the intensity I B of a peak P B of about 1360 cm −1 according to Raman spectroscopy; wherein the graphite powder (A) is produced by heat-treating a graphite consisting essentially of natural graphite to a temperature of 1600° C. to 3200° C.