Synthesis and characterization of LiVOPO4/V2O5 composite cathode for lithium ion batteries

LiVOPO4/V2O5 composites were prepared by a hydrothermal oxidation route and subsequent heat-treatment. The existence of V2O5 in the composites was confirmed using X-ray diffraction. The morphologies of the samples were observed by scanning electron microscopy. The effects of V2O5 content on the electrochemical properties of the composites were investigated by galvanostatic charge-discharge tests and electrochemical impedance spectroscopy. X-ray diffraction revealed that modification with V2O5 did not change LiVOPO4 crystal structure. V2O5-modified LiVOPO4 composites displayed improved discharge specific capacities in comparison with the pristine LiVOPO4 sample. Among the investigated composites, the one with 15 wt% V2O5 showed the best electrochemical performance, which might be contributed to a significant decrease in the interfacial resistance by modification with V2O5.