Electrochemical Performance of the Li₃V₂(PO₄)₃/C Synthesized from V₂O₃

Abstract

Li 3 V 2 (PO 4 ) 3 /C with monoclinic structure were prepared respectively by V 2 O 5 and low valence vanadium oxide V 2 O 3 via solid state reaction. The structure, particle size and morphology of the powders were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed the pure phase Li 3 V 2 (PO 4 ) 3 with the highest performance can be synthesized at 750 degree by using V 2 O 3 vanadium source. The capacity retention had nearly 100% after 40-cycles at 0.5 C. It has relative capacity retention and higher specific capacity, comparing with V 2 O 5 vanadium source at the optimal synthesis temperature. The electrochemical impedance spectra (EIS) manifests the capacity degradation was mainly caused by the increased solution impedance and electrochemical impedance.