Carbon coated Li3V2(PO4)3 from the single-source precursor, Li2(VO)2(HPO4)2(C2O4)·6H2O as cathode and anode materials for Lithium ion batteries

•Single source precursor used for Li3V2(PO4)3 synthesis.•Carbon coating was achieved by sucrose addition prior to thermal decomposition.•Shows stable electrochemical performance as both cathode and anode material.

Monoclinic phase of Li3V2(PO4)3 has been synthesized by thermal decomposition of a single source precursor, Li2(VO)2(HPO4)2(C2O4)·6H2O. This lithium vanadyl oxalatophosphate was obtained by a hydrothermal reaction at 120 °C and subsequent annealing at 800 °C in Argon atmosphere resulted in Li3V2(PO4)3-V2O3 composite material. Carbon coating has been achieved by the addition of sucrose to the precursor prior to thermal decomposition. Lithium intercalation/de-intercalation in the compound has been studied at different voltage ranges using galvanostatic charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy studies. The carbon coated sample has a BET surface area of 75 m2 g−1 and it shows good capacity retention in the voltage range of 2.5-4.3 V. In comparison, pristine Li3V2(PO4)3 which has a lesser surface area of 5.4 m2 g−1 shows inferior electrochemical performance. Stable reversible lithium insertion into Li3V2(PO4)3 forming Li5V2(PO4)3 has also been observed when cycled in the voltage range of 1-3 V.

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