Study On The Synthesis And Electrochemical Performance Of Li_1+x V₃O₈

Li1+xV3O8 is regarded as a promising cathode material in Li ions battery, for its high capacity and special electrochemical performance. Past studies show that the electrochemical performance of Li1+xV3O8 remarkably depends on synthesis methods . In this paper three kinds of solid phase sintering methods were employed to synthesize Li1+xV3O8 samples, in which the first included the solid phase sintering process in the temperature range 480 to 680C ;the second included the microwave sintering process ; the third included the simultaneity doped process on the basis of second microwave sintering method .The connection between electrochemical performance and synthesis conditions studied by the modern experimental techniques , such as XRD, FT-IR, TEM, Cyclic voltammetry , charge-discharge experiment, storage experiment etc.Experiments indicate that the samples synthesized by pure solid phase sintering method hold stick-shape. The discharge capacity of 480C sample is 218mAh/g at the first cycle and the declined rate of discharge capacity is 27% in 40 cycles. The discharge capacity of 680C sample is 128mAh/g at the first cycle , nevertheless its declined rate is only 3%.The sample synthesized by the microwave sintering has a kind of sphere-shape with a particle sizes about 150-300nm. XRD diffraction peaks of samples of microwave sintering is obviously expanded . The discharge capacity of sample synthesized by microwave sintering have 210mAh/g discharge capacity at first cycle , while have 202mAh/g capacity after 40 cycles, which show better cycle and stored performance than other samples. TiO2 doped further improved the electrochemical performance . Several special spectrum characters are measured .