Carbon-coated nano-Si dispersed oxides/graphite composites as anode material for lithium ion batteries

A carbon-coated nano-Si dispersed oxides/graphite composite has been prepared and investigated as a potential anode material for lithium ion batteries. The nano-Si dispersed oxides were synthesized by mechanochemical reduction of SiO by A1, and carbon has been coated onto the ball milled mixture of nano-Si dispersed oxide/graphite by utilizing pyrolysis of coal-tar pitch at 900degreesC in an argon flow. The carbon-coated composites show excellent cycling performance with a reasonable value of the first irreversible capacity. The superior electrochemical characteristics are attributed to the uniform distribution of nano-sized Si phase, the buffering action of graphite and an enhanced connection for electronic and ionic conduction by carbon-coating. (C) 2004 Elsevier B.V. All rights reserved.