Electrochemical Characteristics of Lithium Vanadium Oxide for Lithium Secondary Battery

摘要

The pure crystalline Li1.1V0.9O2 powder has been prepared by a simple solid state reaction of Li2CO3 and V2O3 precursors under nitrogen gas containing 10 mol % hydrogen gas flow. The structure of Li1.1V0.9O2 powder was analyzed using Xray diffraction (XRD) and scanning electron microscope (SEM). The stoichiometric Li1.1V0.9O2 powder was used as anode active material for lithium secondary batteries. Its electrochemical properties were investigated by cyclic voltammetry and constant current methods using lithium foil electrode. The observed specific discharge capacity and charge capacity were 360 mAh/g and 260 mAh/g during the first cycle, respectively. In addition, the cyclic efficiency of this cell was 72.2% in the first cycle. The specific capacity of Li1.1V0.9O2 anode rapidly declines as the current rate increases and retains only 30 % of the capacity of 0.1C rate at 1C rate. The crystallinity of the Li1.1V0.9O2 anode decrease as discharge reaction proceeds. However, the relative intensity of main peaks was almost recovered when the cell was charged up to 1.5 V.