As a promising cathode material for the next generation of lithium-ion batteries (LIBs), Li-rich layered oxides can deliver discharge capacities of 250-300 mAh/g, which is most likely to meet the requirements of higher power density and higher efficiency for electric vehicles. However, the practical application of Li-rich layered oxides has been hindered due to several limitations, such as phase transition, migration of transition metal ions, voltage fade, hysteresis, impedance at low states of charge, poor rate performance. Surface modification has been proven to be an effective way to improve the electrochemical performance of Li-rich layered oxides. However, it’s 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 ultra-thin AlF₃-Al₂O₃ film was coated on the surface of Li_1.2Mn_0.54Co_0.13Ni_0.13O₂ (LRNMC) particles by atomic layer deposition (ALD). The XPS, SEM, and TEM results indicate that a cathode electrolyte interphase layer mainly composed of inorganic components was formed on the surface of coated LRNMC particles during the charge/discharge cycling process, which provided effective protection for the cathode material from the erosion of electrolyte, suppressed side reactions between the electrolyte and the electrode, decreased the dissolution of transition metal ions, and inhibited the transformation of layered phase to a spinel phase. The cycling stability, discharge capacity, and rate performance of AlF₃-Al₂O₃ coated LRNMC were significantly improved.