Improvement of the Cycling Performance and Thermal Stability of Lithium-Ion Batteries by Coating Cathode Materials with Al2O3 Nano Layer

Forming uniform metal oxide nano-coating is a well-known challenge in the construction of coatingmaterials. Herein, we demonstrate the effectiveness of Al2O3 coating on different kinds of core cathode active materials by a simple, facile method, forming a uniform surface-coating layer with thicknesses achieving nanometers precision. Typically, the uniform, nano-sized and controllable Al2O3 coating layer endows LiNi0.5Co0.2Mn0.3O2 cathode material with superior high-voltage cycling and thermal stability. The superior cycling stability can be attributed to the reduced side reactions, decreased polarization and suppressed dissolution of transitionmetals. In addition, we also confirm the coating effect for LiMn2O4 and LiNi0.8Co0.15Al0.05O2, the results show a similar improvement in the electrochemical performance to LiNi0.5Co0.2Mn0.3O2 at high temperature and high operating voltage. (C) 2017 The Electrochemical Society.