Boosting Anionic Redox Reactions of Li‐Rich Cathodes through Lattice Oxygen and Li‐Ion Kinetics Modulation in Working All‐Solid‐State Batteries

Abstract The use of lithium‐rich manganese‐based oxides (LRMOs) as the cathode in all‐solid‐state batteries (ASSBs) holds great potential for realizing high energy density over 600 Wh kg⁻¹. However, their implementation is significantly hindered by the sluggish kinetics and inferior reversibility of anionic redox reactions of oxygen in ASSBs. In this contribution, boron ions (B³⁺) doping and 3D Li₂B₄O₇ (LBO) ionic networks construction are synchronously introduced into LRMO materials (LBO‐LRMO) by mechanochemical and subsequent thermally driven diffusion method. Owing to the high binding energy of B─O and high‐efficiency ionic networks of nanoscale LBO complex in cathode materials, the as‐prepared LBO‐LRMO displays highly reversible and activated anionic redox reactions in ASSBs. The designed LBO‐LRMO interwoven structure enables robust phase and LBO‐LRMO|solid electrolyte interface stability during cycling (over 80% capacity retention after 2000 cycles at 1.0 C with a voltage range of 2.2–4.7 V vs Li/Li⁺). This contribution affords a fundamental understanding of the anionic redox reactions for LRMO in ASSBs and offers an effective strategy to realize highly activated and reversible oxygen redox reactions in LRMO‐based ASSBs.