Synthesis and electrochemical performance of Li 3V 2(PO 4) 3 by optimized sol-gel synthesis routine

Abstract

Li 3V 2(PO 4) 3 samples were synthesized by sol-gel route and high temperature solid-state reaction. The influence of Li 3V 2(PO 4) 3 as cathode materials for lithium-ion batteries on electrochemical performances was investigated. The structure of Li 3V 2(PO 4) 3 as cathode materials for lithium-ion batteries and morphology of Li 3V 2(PO 4) 3 were characterized by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Electrochemical performances were characterized by charge/discharge and AC impedance measurements. Li 3V 2(PO 4) 3 with smaller grain size shows better performances in terms of the discharge capacity and cycle stability. The improved electrochemical properties of Li 3V 2(PO 4) 3 are attributed to the refined grains and enhanced electrical conductivity. AC impedance measurements also show that the Li 3V 2(PO 4) 3 synthesized by sol-gel route exhibits significantly decreased charge-transfer resistance and shortened migration distance of lithium ions.