In Situ Atomic Arrangement and Defect Engineering of Li-Rich Cathodes for Interface Stabilization

Coming research trends will move toward high-energy-density Li-rich manganese layered (LMR) cathodes (>900 Wh kg^-1). Nevertheless, their practical implementation is severely impeded by irreversible lattice oxygen release, progressive structural deterioration, pronounced capacity, and voltage decay. A critical unresolved issue arises from the absence of an effective atomic-scale design principle capable of stabilizing the interfacial structure and suppressing the layer-to-rock salt transformation, an instability pathway that is further aggravated in high-Ni LMR compositions. In this work, we establish an in situ atomic-level regulation strategy through La³⁺/W⁶⁺ codoping, which induces the formation of an interface-disordered phase while preserving the integrity of the layered framework. This strategy provides a direct resolution to this long-standing structural challenge by enabling controlled oxygen-vacancy generation and localized cation rearrangement at the near-surface region, thereby effectively suppressing detrimental phase transitions during electrochemical cycling and simultaneously enhancing Li⁺ transport kinetics. The introduction of robust La-O and W-O bonds further reinforces the interfacial oxygen framework and markedly improves thermal stability. As a consequence, the modified cathode demonstrates substantially enhanced electrochemical durability. Compared with the original sample, the capacity retention rate of LW-3 is 80.25%, which is significantly better than that of LMR (66.26%). Moreover, the results substantiate that high-Ni LMR compositions possess an intrinsic propensity toward layered-to-rock-salt transformation, which profoundly compromises structural and electrochemical stability. This work strengthens the structural integrity and mechanical resilience of LMR cathodes and offers a responsible strategy toward realizing high-energy, long-life Li-rich layered oxides suitable for next-generation energy storage technologies.