Electrochemical properties of the carbon-coated lithium vanadium oxide anode for lithium ion batteries

Carbon-coated Li1.1V0.9O2 powder was prepared by dissolving pure crystalline Li1.1V0.9O2 powder in an ethanol solution containing 10 wt% sucrose and sintering it under an argon atmosphere. The structures of the bare and carbon-coated Li1.1V0.9O2 powders were analyzed using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. These powders were used as anode active materials for lithium ion batteries in order to determine the electrochemical properties via cyclic voltammetry (CV) and constant current methods. CV revealed the carbon-coated Li1.1V0.9O2 anode to have better reversibility during cycling than the bare Li1.1V0.9O2 anode. Carbon-coated Li1.1V0.9O2 also showed a higher specific discharge and charge capacities, as well as lower electrolyte and interfacial resistance properties. The observed specific discharge and charge capacities of the carbon-coated Li1.1V0.9O2 anode were 330 mAh/g and 250 mAh/g, respectively, in the first cycle. In addition, the cyclic efficiency of this cell was 75.8% in the first cycle. After 20 cycles, the specific capacity of the Li1.1V0.9O2 anode was reduced to approximately 50% of its initial capacity, irrespective of the presence of a carbon coating. (C) 2010 Published by Elsevier B.V.