A novel method to synthesize Li_3V_2(PO_4)_3/C composite and its electrochemical Li intercalation performances

摘要

Monoclinic Li_3V_2(PO_4)_3/C composite materials are synthesized from a sucrose-containing precursor by one-step heat treatment. As-prepared composites are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetric (CV) technology and charge/discharge measurement. XRD patterns show that Li_3PO_4 impurity phase appears in the sample synthesized at 600℃ and pure Li_3V_2(PO_4)_3 samples can be obtained when the sintered temperature is higher than 700℃. The sample synthesized at 700℃ presents the highest initial capacity of 170 mAhg~(-1) (at C/5 rate), and exhibits better cycling stability (142 mAh g~(-1) at 50th cycle at C/5 rate) and better rate capability (137 mAh g~(-1) at 30th cycle under 1C rate) in the voltage range of 3.0-4.8 V.