Multiscale Layered/Rocksalt Intergrown to Stabilize Surface and Local Micro‐Structure for Ultrastable Li‐Rich Oxide Cathodes

ABSTRACT Lithium‐rich manganese‐based (LMR) oxides are promising cathodes for next‐generation lithium‐ion batteries (LIBs) due to their high energy density and low cost. However, their practical use is limited by capacity and voltage decay, caused by structural distortion, lattice collapse, and surface degradation. Here, a multiscale layered/rocksalt intergrown (MLR) strategy is proposed to enhance both bulk and surface structural stability. The MLR cathode achieves outstanding capacity retention of 97.0% after 100 cycles at 0.1C and 99.8% after 200 cycles at 0.2C. Synchrotron‐based analyses reveal that the bulk intergrown structure stabilizes the lattice and suppresses phase transitions, while the surface intergrown layer protects against chemical and structural degradation. This work demonstrates that the multiscale intergrown approach can effectively stabilize the bulk long‐range and short‐range structure as well as the surface microstructure of layered oxide cathodes. This strategy is expected to accelerate the development of advanced cathode materials for next‐generation LIBs.