Synthesis and Electrochemical Properties of Li3V2(PO4)(3)-LiMnPO4 Composite Cathode Material for Lithium-ion Batteries

Abstract

Carbon-coated Li3V2(PO4)(3)-LiMnPO4 composite cathode materials are first reported in this work, prepared by the mechanochemical process with a complex metal oxide as the precursor and sucrose as the carbon source. X-ray diffraction pattern of the composite material indicates that both olivine LiMnPO4 and monoclinic Li3V2(PO4)(3) co-exist. We further investigated the electrochemical properties of our Li3V2(PO4)(3)-LiMnPO4 composite cathode materials using galvanostatic charging/discharging tests, where our Li3V2(PO4)(3)-LiMnPO4 composite electrode materials exhibit the charge/discharge efficiency of 91.9%, while Li3V2(PO4)(3) and LiMnPO4 exhibit the efficiency of 87.7 and 86.7% in the first cycle. The composites display unique electrochemical performances in terms of overvoltage and cycle stability, displaying a reduced gap of 141.6 mV between charge and discharge voltage and 95.0% capacity efficiency after 15th cycles.