A Carbothermal Reduction Method for the Preparation of Electroactive Materials for Lithium Ion Applications

A novel preparative method based on a carbothermal reduction (CTR) process is described for the synthesis of the representative electroactive materials, and In the CTR procedure a high surface area carbon is mixed intimately with appropriate precursor compounds and the mixture heated in an inert atmosphere. Use is then made of the two carbon oxidation reactions, namely, and which facilitate controlled transition metal reduction while also allowing lithium ion incorporation. Electrochemical performance evaluation indicates that the CTR is capable of cycling at a material utilization of 130 mAh/g, a figure that compares favorably with the theoretical specific capacity of 142 mAh/g. The insertion behavior of the lithium vanadium phosphate shows a specific capacity equivalent to the reversible cycling of two lithium ions per formula unit. In summary, we believe the CTR method to be an energy-efficient, economical, and convenient process to produce a wide range of electroactive compounds. It appears ideally suited to preparation of active materials for use in lithium ion applications. © 2003 The Electrochemical Society. All rights reserved.