Enhanced Electrochemical Properties of LiNi0.8Co0.1Mn0.1O2 Cathode Materials Modified with Lithium-Ion Conductive Coating LiNbO3

As a promising cathode material for lithium-ion batteries, nitrogen-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) attracts great attention for its high specific capacity, but the rapid capacity decline of NCM811 in the process of charge/discharge restricts its extensive application. To alleviate the capacity decline for NCM811, a solid electrolyte LiNbO3 material with lithium-ion diffusion and electron conduction activity was successfully coated on the surface of NCM811 by adopting a simple two-step method, and the amount of the LiNbO3 coating layer was investigated. Powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the as-prepared cathode materials. The experimental results revealed that the LiNbO3 played a role in reducing surface residual alkalis and protecting NCM811 from erosion by electrolyte. When the weight ratio of LiNbO3 and NCM811 was 1 %, the corresponding 1 wt % LNO@NCM material displayed the best cycle performance and rate capability, whose capacity retention at 1 C after 200 cycles, and discharge capacity at 10 C are 90.1 % and 122.7 mAh g(-1), respectively.