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

Abstract

AbstractAs 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.