Facile synthesis of porous Li3V2(PO4)3/C composite and its superior electrochemical performance for lithium ion battery

• Porous Li3V2(PO4)3/C was prepared through a facile PVP-assisted sol-gel method.
• The sublimation and decomposition of oxalic acid form the pore structure.
• PVP was used as a carbon source and chelating reagent.
• The Li3V2(PO4)3/C sample exhibits a discharge capacitiy of 108.0 mAh g−1 at 20C between 3.0 and 4.5 V.

Porous structure Li3V2(PO4)3/C composite has been successfully prepared through a facile PVP-assisted sol-gel method, following by high temperature sintering. SEM and TEM results show that the Li3V2(PO4)3/C composite has a pore structure with a carbon coating of about 6 nm. In the voltage range of 3.0–4.5 V, discharge capacities of 130.3, 125.1, 118.3, 113.5 and 108.0 mAh g−1 can be delivered at 0.1, 1, 5, 10 and 20 C, respectively. Moreover, it exhibits discharge capacities of 130.4 and 177.8 mAh g−1 at 1 C in the voltage range of 3.0–4.8 V and 1.5–4.5 V, respectively. These results demonstrate that the rate capability and cyclability of Li3V2(PO4)3/C can be ameliorated by the porous structure.