Constructing Epitaxial Lattice Matching Rock‐salt Interface Toward High Structural Adaptability for Lithium‐Rich Manganese‐Based Oxides

Lithium‐rich manganese‐based oxides (LRMO) with high reversible energy densities are considered as a promising candidate for overcoming the energy density bottleneck of lithium‐ion batteries (LIBs). However, the volume variation associated with anisotropic lattice strain and stress during lithium (de)intercalation can lead to severe surface structure degradation and lattice oxygen loss in cathode materials, ultimately resulting in accelerated attenuation of energy density. Herein, we propose an epitaxial lattice matching strategy in which an epitaxial disordered rock‐salt layer is coherently grown on the surface to effectively restrain the extension of strain and displacement. Specifically, the disordered rock‐salt layer can alleviate lattice strain and inhibit irreversible oxygen release. While the incorporation of boron can adjust the electronic structure, enhance the interaction between transition metals and oxygen, and accelerate Li + diffusion. The modified LRMO cathode exhibits significantly enhanced cycling stability (83% capacity retention after 300 cycles at 1C vs. 64% for the LRMO), superior rate capability (183.5 mAh g −1 at 5C vs. 147.3 mAh g −1 ), and improved voltage retention. This study offers a powerful interface engineering strategy to fundamentally resolve the strain‐induced structural degradation, paving the way for the development of lithium‐rich cathode materials with high adaptability to interface structures.