STRUCTURE AND LITHIATION MECHANISM OF THE SPINEL, LICUVO4

The structure of lithium copper vanadate, LiCuVO4, was determined by X-ray Rietveld analysis and its electrochemical properties were examined. The distortion of the CuO6 octahedra is appreciably large and is induced by the Jahn-Teller instability of Cu2+ ions. The CuO6 octahedra connected one dimensionally by sharing opposite O-O edges such that the elongated axis ordered ferrodistortive way. The charge-discharge properties of the Li/LiCuVO4 cells were examined. The spinel transformed to a new phase, Li2.5Cu0.5VO4, with lithiation, and the new phase was lithiated reversibly by the electrochemical displacement reaction between the lithium and the copper ions. © 1990.