Chemical Vapor Deposited Silicon∕Graphite Compound Material as Negative Electrode for Lithium-Ion Batteries

Abstract

Chemical vapor deposition of nanosilicon on the surface of fine particle graphite (TIMREX KS6) gave a silicon/graphite "compound" material with 7.1 wt % silicon, homogeneously distributed on the carbon surface as very small particles (10-20 nm). This material shows good electrochemical properties, above all high reversible specific charge capacity and low fading. The irreversible capacity loss, upon the first cycle, only slightly exceeds that of graphite alone. The specific reversible capacity of the silicon part alone exceeds 2500 mAh g<sup>-1</sup> at the beginning of the cycling and is still more than 1900 mAh g<sup>-1</sup> for over 100 cycles.