LiNbO-coated LiMnNiCoO as a cathode material with enhanced electrochemical performances for lithium-ion batteries

Lithium-rich manganese-based cathode materials have become one of the most concerned cathode materials for high-energy lithium-ion batteries. In order to improve its electrochemical performance, LiMnNiCoO with different content LiNbO coatings was synthesized by mechanical ball milling. The morphology, microstructure, and electrochemical properties of the samples were investigated by X-ray diffraction, scanning electron microscope, transmission electron microscope, galvanostatic charge/discharge, electrochemical impedance spectroscopy, and cyclic voltammetry. The results show that LiNbO coating not only protects the cathode material from the corrosion of electrolyte and HF but also improves the migration rate of Li in the interface region. Notably, the 5 wt% LiNbO-coated LiMnNiCoO exhibits capacity retention of 89.9% under 0.1 C after 100 cycles. Besides, it has a higher discharge capacity than LiMnNiCoO at different rates. LiNbO coating is an effective way to improve its cycle stability and rate performance of LiMnNiCoO.