Synthesis of high performance Li3V2(PO4)3/C cathode material by ultrasonic-assisted sol-gel method

A novel ultrasonic-assisted sol-gel method is proposed to prepare Li3V2(PO4)(3)/C cathode material. X-ray diffraction analyses show that both Li3V2(PO4)(3)/C(A) synthesized by the ultrasonic-assisted sol-gel method and Li3V2(PO4)(3)/C(B) synthesized by a traditional sol-gel method have monoclinic structure. Scanning electron microscopy images indicate that the Li3V2(PO4)(3)/C(A) composite has a more uniform morphology than that of the Li3V2(PO4)(3)/C(B) composite. In the voltage range of 3.0-4.3 V (vs. Li/Li+), the initial specific discharge capacities of the Li3V2(PO4)(3)/C(A) and Li3V2(PO4)(3)/C(B) samples are 129.8 and 125.9 mAh g(-1) at 1C rate (1C = 133 mA g(-1)), respectively. Furthermore, at 2-C charge/10-C discharge rate, the specific discharge capacity of the Li3V2(PO4)(3)/C(A) composite retains 113.2 mAh g(-1) after 50 cycles, but the Li3V2(PO4)(3)/C(B) composite only presents a capacity of 94.8 mAh g(-1).