A NEW METHOD FOR PREPARING LITHIATED VANADIUM-OXIDES AND THEIR ELECTROCHEMICAL PERFORMANCE IN SECONDARY LITHIUM BATTERIES

This paper describes a new method for preparing lithiated vanadium oxi des which are suitable as the cathode material for secondary lithium b atteries. Characterization by powder X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and thermogravi metric analysis (TGA) shows that these oxides are somewhat structurall y different from LiV3O8 prepared by the solid-state reaction route, al though the starting materials are identical in both cases. The dischar ge capacity of the oxide is much higher than that of crystalline LiV3O 8, and can attain 250 mAh g(-1) at the current density of 0.2 mA cm(-2 ). The specific capacity and the cycling behaviour of these lithiated vanadium oxides are closely related to post-synthesis heat treatment. This suggests that the amount of water bound to the structure determin es electrochemical performance of the oxide in secondary lithium batte ries. (C) 1998 Elsevier Science S.A. All rights reserved.