Synthesis and electrochemical performance of Li3V2(PO4)3 by optimized sol-gel synthesis routine

Li3V2(PO4)3 samples were synthesized by sol-gel route and high temperature solid-state reaction. The influence of Li3V2(PO4)3 as cathode materials for lithium-ion batteries on electrochemical performances was investigated. The structure of Li3V2(PO4)3 as cathode materials for lithium-ion batteries and morphology of Li3V2(PO4)3 were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Electrochemical performances were characterized by charge/discharge and AC impedance measurements. Li3V2(PO4)3 with smaller grain size shows better performances in terms of the discharge capacity and cycle stability. The improved electrochemical properties of Li3V2(PO4)3 are attributed to the refined grains and enhanced electrical conductivity. AC impedance measurements also show that the Li3V2(PO4)3 synthesized by sol-gel route exhibits significantly decreased charge-transfer resistance and shortened migration distance of lithium ions.