The Li 3V 2(PO 4) 3/C composites with high-rate capability prepared by a maltose-based sol–gel route

Abstract

The carbon coated monoclinic Li 3V 2(PO 4) 3 (LVP/C) cathode materials are synthesized via a sol–gel method using oxalic acid as a chelating reagent and maltose as a carbon source. The effect of carbon content on the synthesis of LVP/C composites is investigated using X-ray diffraction, scanning electron microscopy, galvanostatic charge/discharge and DC resistance measurements. The results show that, among the LVP/C powders with different carbon content (5.7, 9.6, 11.6 and 15.3 wt.%), the sample with 11.6 wt.% carbon content gives rise to the corresponding (LVP/C) ∥Li half cell with a low DC resistance and superior electrochemical performance, especially with excellent rate capability. Its discharge capacity decreases by only 7.2% from 125 mAh g −1 at 0.5 C to 116 mAh g −1 at 5 C between 3.0 and 4.3 V. The maltose-based sol–gel method is feasible for the preparation of LVP/C composites for high power lithium ion batteries.