Natural flake graphite modified by mild oxidation and carbon coating treatment as anode material for lithium ion batteries

Abstract

In this paper, natural flake graphite was treated by mild oxidation and carbon coating techniques. The effects of modification on the crystal structure, morphology and electrochemical performance were investigated. The results indicate that the interlayer distance of flake graphite increases, and shape operation of graphite particle occurs after modification. Electrochemical measurements show that the initial columbic efficiency of graphite anode material increases from 73.4% to 89.7% after mild oxidation treatment, and the reversible capacity of composite that coated with pyrolytic carbon is about 359.7mAh g-1, and its cycling performance is improved. The modification results in a decrease of electrochemical polarization of graphite anode and an increase of the diffusion coefficient of lithium in graphite. Thus, the rate capacity is improved.