The studies of lattice parameter and electrochemical behavior for Li3V2(PO4)3/C cathode materials

Abstract Single-phase, nano-sized Li 3 V 2 (PO 4 ) 3 /C materials with the monoclinic structure were prepared by a modified sol–gel method, in which the precursor materials were sintered at 750, 800, 850, and 900 °C, respectively The X-ray diffraction (XRD) patterns of all the materials were consistent with the monoclinic structure without any impurities. The LVP/C composite sintered at 800 °C was selected as the most promising material on the basis of the lattice parameters ( a  = 8.605 A, b  = 8.596 A, c  = 14.732 A, β  = 125.20°, V = 890.59 A 3 ), crystallite size (99 nm), and morphology (5–6 nm carbon layer). The LVP/C composite sintered at 800 °C showed a high specific capacity with excellent kinetic properties (capacity of 130 and 170 mAh g −1 at voltages of 3.0–4.3 and 4.8 V at 0.1C, 25 °C), which showed about 98%, 86% of its theoretical capacity, respectively.