Patent ID: 8647776

Claim:
A carbon material for lithium ion secondary battery having a surface functional group amount O/C, a surface functional group amount Cl/C, and a surface functional group amount S165/C, wherein the surface functional group amount O/C value represented by the following formula 1 is from 1 to 4% and a sum (Cl/C+S165/C) of the surface functional group amount Cl/C value represented by the following formula 2 and the surface functional group amount S165/C value represented by the following formula 3 is from 0.05 to 0.5%: O/C value (%)=O atom concentration determined based on the peak area of the spectrum of O1s in X-ray photoelectron spectroscopy (XPS) analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100 Formula 1: Cl/C value (%)=Cl atom concentration determined based on the peak area of the spectrum of Cl2p in XPS analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100 Formula 2: S165/C value (%)=S165 atom concentration based on the peak area of the peak near 165 eV in the spectrum corresponding to S2p in XPS analysis/C atom concentration determined based on the peak area of the spectrum of C1s in XPS analysis×100 Formula 3.