Electrochemical properties of LiV_3O_8 cathode material with the addition ofY~(3+)and F~-

摘要

Y~(3+) and P~- added LiV_3O_8 was synthesized by solid-state reaction. X-ray diffraction (XRD) and scanning electron microscope (SEM) tests show that Y~(3+) and F~- addition can modify the structure and surface morphology of the material although inducing small amount of impurities in it. Charge-discharge tests show that Y~(3+) and F~- addition can significantly improve the cyclic ability of the material although decreasing its initial discharge capacities simultaneously. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests further approve that Y~(3+) and F~- addition can stabilize the electrochemical properties of the material during cycling. Yttrium and fluorine dual doping is a good method for improving the electrochemical performances of LiV_3O_8.