Synthesis and characterization of LiVOPO 4 /V 2 O 5 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.