Improvement of the Cycling Performance and Thermal Stability of Lithium-Ion Batteries by Coating Cathode Materials with Al₂O₃Nano Layer

Forming uniform metal oxide nano-coating is a well-known challenge in the construction of coating materials. Herein, we demonstrate the effectiveness of Al 2 O 3 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 Al 2 O 3 coating layer endows LiNi 0.5 Co 0.2 Mn 0.3 O 2 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 transition metals. In addition, we also confirm the coating effect for LiMn 2 O 4 and LiNi 0.8 Co 0.15 Al 0.05 O 2 , the results show a similar improvement in the electrochemical performance to LiNi 0.5 Co 0.2 Mn 0.3 O 2 at high temperature and high operating voltage.