Metal film deposition on carbon anodes for high rate charge-discharge of Li-ion batteries

Carbon is the most promising active material for the anode of Li-ion secondary batteries because of its reliability. The high rate characteristics of carbon, however are not satisfactory to meet the requirements of advanced appliances. Art attempt has been made to improve the high rate capability by modifying carbon surfaces by heat treatment, but with limited success. In addition, a novel method based on metal film coating of cal bon surfaces has been developed. Graphitised mesophase carbon fibre was used as the carbon substrate and several metals were examined including Au, Bi, Pd and Sn. A metal film was deposited on the carbon fibre surface with a thickness of 5 to 100 nm. The electrochemical charge-discharge cycle test was performed in a non-aqueous electrolyte containing IM LiClO(4). The presence of the metallic film increased the charge-discharge current for all metals examined. (C) 1999 IoM Communications Ltd.