Influences of precursor's processing method on the electrochemical properties of synthesized lithium vanadium phosphate

摘要

Li_3V_2(PO_4)_3/C composite cathode material was synthesized by solid state method using LiOH·H_2O, NH_4H_2PO_4, NH_4VO_3 as raw materials, sucrose as carbon source, and two kinds of precursor's treatment such as pre-sintering and hydrothermal methods. The effect of different precursor's treatment methods on the electrochemical properties of the material was investigated. The results showed that the samples treated with hydrothermal process has smaller particle size and the initial discharge specific capacity of 119mAh/g, the capacity retention rate is 85% after 20 cycles. But the samples treated with pre-sintering (without hydrothermal process) has larger particle size and the initial discharge specific capacity 103.2mAh/g, the capacity retention rate is only 72% after 20 cycles. These results can be attributed to that the hydrothermally treated sample has smaller particle sizes, higher conductivity and shorter distances of lithium ion diffusion and electron mobility, thus the electrochemical performances are improved.