Li-rich manganese-based cathode materials are known as one of the most promising cathode materials for next-generation lithium batteries due to their high theoretical specific capacity. However, there are problems such as low specific capacity, poor rate performance, and fast decay rate during cycling. In this paper, spherical lithium-rich manganese-based cathode material Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ was prepared by co-precipitation method, and aluminum fluoride (AlF₃) was prepared by high temperature solid state reaction, so that AlF₃ was uniformly coated on lithium-rich manganese-based cathode. The results show that AlF₃ is uniformly coated on the surface of the spherical Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ material with a thickness of about 5~7 nm, and the material maintains the original layered structure without changing. The charge–discharge cycle test was carried out in the voltage range of 2.0~4.8 V, and the specific capacity of the Li-rich manganese-based cathode material coated with AlF₃ was significantly improved, reaching 283.3 mAh/g (Under the same preparation method and test conditions, this value is in the forefront of the 260–290 mAh/g that can be achieved by most of the current coating methods). The AlF₃ coating with the best retention performance is 4 wt% and still has a retention rate of 84.4% after 200 charge–discharge cycles. During the charging and discharging process, AlF₃ can maintain the stability of the main cathode material and inhibit the next transformation, thereby ensuring the high specific capacity and cycle stability of the material.

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