Enhanced electrochemical performance of lithium vanadium phosphate as cathode by LiBOB/LiTFSI with additive in EC/EMC

Abstract

A series of Li3V2(PO4)3/C (LVP/C) samples with monoclinic structure indexed to P21/n space group were synthesized using V2O3 as vanadium source by solid state reaction method by different sintering temperatures. It was found that the LVP/C sintered at 750 °C with a carbon content 3 wt.% was the optimum condition for this synthesis. The structural, morphological, superficial, and textural properties of LVP/C were characterized by XRD, SEM, TEM, and XPS. The electrochemical performance was evaluated by galvanostatic charge–discharge cycling using new high voltage electrolyte. The optimized cell delivered an initial discharge capacity of 187 mAh g−1 in the higher cut-off voltage of 3.0–4.8 V vs. Li+/Li0 at 0.2 C rate, with a capacity retention of 88 %, 89 %, and 61 % after 50 cycles discharging at 1 C, 2 C, and 4 C, respectively. The capacity can be almost recovered at 0.5 C after long cycles. The excellent stability is contributed to the new high-voltage electrolyte.