Multi-Walled Carbon Nanotubes Modified Li3V2(PO4)3/Carbon Composites with Enhanced Electrochemical Performances as Cathode Materials for Li-Ion Batteries

The multi-walled carbon nanotubes (MWCNTs) modified Li3V2(PO4)3/carbon composites (MWCNTs-LVPCs) are synthesized through the rheological phase reaction method using MWCNTs as a highly conductive agent. MWCNTs-LVPCs are characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscope. Charge-discharge cycling performance is also used to characterize the electrochemical properties. X-ray diffraction result reveals that the added MWCNTs do not have a significant effect on the crystal structure of MWCNTs-LVPCs, however, crystal particles growth of MWCNTs-LVPCs are dramatically inhibited by MWCNTs in scanning electron microscopy test. The electrochemical measurements show that the 1.0 wt.%-MWCNTs-LVPC composite yields the highest discharge specific capacity of 182.38 and 163.93 mAh g−1 at current rate of 15 and 90 mA g–1 among all the MWCNTs-LVPCs, which are much higher than those of Li3V2(PO4)3/carbon composite. After 100 cycles, the 1.0 wt.%-MWCNTs-LVPC composite still maintains a stable capacity of 125.37 mAh g–1. Therefore, construction of MWCNTs modified Li3V2(PO4)3/carbon composites offers an effective and convenient technique to improve the conductivity and electrochemical performances of Li3V2(PO4)3/carbon composites.