Synthesis and electrochemical performance of 0.6Li3V2(PO4)3·0.4Li–V–O composite cathode material for lithium ion batteries

A novel 0.6Li3V2(PO4)3·0.4Li–V–O composite cathode material is synthesized by sol-gel method followed by solvothermal and solid state reaction. The morphology and structure of the composite are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photo-electron spectroscopy (XPS). The composite particles are well-crystallized and present uniform nanoplate alike. Except Li3V2(PO4)3 phase, LiV2O5 and VO2 are also present in the composite. The 0.6Li3V2(PO4)3·0.4Li–V–O electrode delivers a discharge capacity of 149.3 mAh g−1 at 50 mAg−1 between 2.0 V and 4.3 V, and has higher rate property than Li3V2(PO4)3. The diffusion coefficients of Li ions in the composite are in the range of 10−9.5 − 10−7.5 cm2 s−1 obtained from galvanostatic intermittent titration technique (GITT).