Enhanced electrochemical performance of LiNi0.8Co0.1Mn0.1O2 with lithium-reactive Li3VO4 coating

A cathode material LiNi0.8Co0.1Mn0.1O2 coated with ionic conductor Li3VO4 was prepared through a wet-chemical method. The crystalline phase, chemical valence state and the microstructure of Li3VO4-coated material were investigated by X-ray diffraction, energy dispersive spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. The existence of the Li3VO4 coating layer on the surface of sphere particle was validated, and the electrochemical performances of the samples were investigated. The 3 wt% Li3VO4-coated sample exhibited the most remarkable cycling capability at 1 C after 100 cycles, with a retention value of 83.54%. Moreover, the rate performances of all Li3VO4-coated samples were significantly enhanced at high rates (2, 5 and 10 C). Electrochemical impedance spectroscopy and cyclic voltammetry performance analyses revealed that the excellent electrochemical performance of the Li3VO4-coated sample is ascribed to the improved lithium ion conductivity and the suppression of the chemical reaction between the electrode material and electrolyte.