AbstractCapacity attenuation caused by Ni dissolution and interface instability during cycling is a major challenge because it limits the application of high Ni ternary cathode materials in Li‐ion batteries. In this paper, ternary LiNi0.85Co0.10Mn0.05O2 cathode with high nickel content was prepared by co‐precipitation method, and then was coated with perovskite La4NiLiO8 via the simple thermochemical method. The analysis of the images of transmission electron microscope (TEM) showed that the coating is uniformly covered on the surface of NCM85 material with a thickness of 5 nm. Compared to uncoated sample, the La4NiLiO8‐coated LiNi0.85Co0.10Mn0.05O2 material shows lower electrochemical impedance and better cyclic stability, the initial kinetic diffusion coefficient and the interface stability of the prepared material are greatly improved. Meanwhile, the problems of Li+/Ni2+ mixing are also been solved. This work provides a new strategy for improving the interface and thermal stability of the nickel cathode material of Li‐ion battery in the future.