Synthesis of Copper-and Iron-Doped Lithium Vanadium Oxides for Use as Negative Electrode Materials in Lithium-Ion Batteries

Abstract

Li3VO4 has been considered a promising negative electrode material because of its high theoretical capacity (394 mAh g−1) and zero strain during the charge and discharge processes. However, the electronic conductivity of Li3VO4 is low, which has led to an electrochemical performance unfavorable for practical application. In this study, copper- and iron-doped Li3VO4 are prepared by a simple and inexpensive sol-gel method. The doped Li3VO4 delivers high initial discharge and charge capacities of up to 70 mAh g−1 after 30 cycles for 5% Fe-doped material at a rate of 0.5 C. Conductive Cu and Fe are found to enable better Li+ ion storage due to the improved electronic conductivity, Li ion diffusion, and structure stability, improving cycling and rate performance. This work provides some hints for preparing Li3VO4 based negative electrodes with high electrochemical performance.