AlF3-Al2O3 ALD Thin-Film-Coated Li1.2Mn0.54Co0.13Ni0.13O2 Particles for Lithium-Ion Batteries: Long-Term Protection.

Abstract

Improving the performance of existing cathode materials of lithium-ion batteries (LIBs) through surface modification has been proven to be an effective way to improve the performance of LIBs. However, it is a challenge to use a traditional method to prepare an effective coating film, which meets the requirements of uniformity, continuity, electrochemical stability, and strong mechanical properties. In this study, an ultrathin AlF3-Al2O3 film was coated on the surface of Li1.2Mn0.54Co0.13Ni0.13O2 (LRNMC) particles by atomic layer deposition (ALD) in a fluidized bed reactor. A cathode electrolyte interphase layer mainly composed of inorganic components was formed on the surface of AlF3-Al2O3-coated LRNMC during the charge/discharge cycling process, which led to the enhancement of capacity and cycling stability. In addition, the coating layer significantly increased the shelf life of the cathode particles. For LRNMC particles with one cycle of Al2O3 ALD and one cycle of AlF3 ALD coatings, there was no obvious degradation of electrochemical performance after being stored for more than 1 year, indicating long-term protection of ALD films for LIB cathode particles.