Synthesis and performances of 2LiFePO4·Li3V2(PO4)3/C cathode materials via spray drying method with double carbon sources

• Spherical 2LiFePO4·Li3V2(PO4)3/C composite was synthesized via spray-drying process.
• The raw materials are Fe4(VO4)4·5H2O, LiH2PO4, glucose and oxalic acid.
• 2LiFePO4·Li3V2(PO4)3/C composite has a high tap density of 1.66 g cm−3.
• 2LiFePO4·Li3V2(PO4)3/C composite shows excellent capacity and rate performance.

The 2LiFePO4·Li3V2(PO4)3/C samples are synthesized through spray drying method. Glucose and oxalic acid are used as collaborative carbon sources to improve the electrochemical performance of 2LiFePO4·Li3V2(PO4)3/C composites. XRD results reveal the LiFePO4·Li3V2(PO4)3/C samples are composed of orthorhombic LiFePO4 and monoclinic Li3V2(PO4)3 phases. SEM results reveal that the nano-spherical Fe4(VO4)4·5H2O are about 80 nm and the 2LiFePO4·Li3V2(PO4)3/C composites possess a micro-nano spherical morphology with carbon coating layer. The samples show the best electrochemical performance when the mass ration of glucose and oxalic is 6:4, it can deliver a capacity of 147.6 mAh g−1, 145.0 mAh g−1, 134.1 mAh g−1 and 123.0 mAh g−1 at the rates of 0.1C, 1C, 5C and 10C, respectively.