Electrochemical properties of lithium vanadium phosphate as a cathode material for lithium-ion batteries

The properties of the monoclinic lithium vanadium phosphate Li3V2 (PO4)(3) are investigated using X-ray diffraction (XRD) and electrochemical methods. Electrochemical measurements conducted in half-cells with Li3V2 (PO4)(3) as the cathode material and lithium metal as the anode have shown that this material exhibits an excellent reversibility when the charge extracted is confined to that equivalent to two lithiums per formula unit. The extraction of the last lithium is observed at a potential greater than 4.6 V vs. Li/Li+ and involves a significant overvoltage. Upon discharge, however, XRD has shown that the original structure is recovered. (C) 2002 The Electrochemical Society.