Cu-coated Li3V2(PO4)3/carbon as high-performance cathode material for lithium-ion batteries

Abstract

The development of lithium-ion batteries is hindered by the lack of appropriate low-cost cathode materials with high performance. Here, the preparation of Cu-coated Li3V2(PO4)3/C (x% Cu-LVPC) composites is reported via a chemical precipitation and self-reduction method. With an optimized Cu coating content of 2.0 wt%, the 2.0% Cu-LVPC composite displays the best electrochemical properties. The initial discharge capacity of 2.0% Cu-LVPC is 175 mA h g−1 at 0.15 C (30 mA g−1) in the voltage range from 3.0 to 4.8 V and the capacity retention is 86.3% after 50 cycles, whereas pristine LVPC has an initial capacity of 163 mA h g−1 and retains 82.2% of the capacity after 50 cycles. Moreover, the rate capacity of 2.0% Cu-LVPC is also increased under different current densities and 2.0% Cu-LVPC exhibits excellent long-term cycling performance of 89 mA h g−1 after 1000 cycles at 10 C. The enhanced electrochemical properties are attributed to the uniform coating of the metal conductor Cu on the LVPC surface, which is conducive to electron transfer and extraction/insertion of Li+ ions.