Stabilizing Lattice Oxygen in Li-Rich Layered Cathodes by Boron-Doping Induced Anchoring Effect

Li-rich Mn-based layered oxides (LRMLOs) have emerged as promising cathode candidates owing to their exceptional specific capacity (>300 mAh/g), high energy density (>1000 Wh/kg), and elevated operating voltages (>3.5 V vs Li⁺/Li). Nevertheless, the sluggish kinetics and poor reversibility of oxygen anion redox reactions fundamentally limit their practical implementation. Herein, we propose an interstitial boron doping strategy that precisely incorporates B atoms into the interstices between lithium and transition metal layers, creating robust BO₄ coordination structures with enhanced B-O covalency. Multiscale characterization reveals that boron doping reduces oxygen Bader charges and increases oxygen vacancy formation energy, effectively suppressing the overoxidation of oxygen while stabilizing oxygen sublattices. Electrochemical evaluation demonstrates significantly improved cyclability with 63.6% capacity retention after 50 cycles at 0.05 C, a 19.3% enhancement compared to that of undoped counterparts. Density functional theory (DFT) calculations further verify that boron incorporation downshifts the O 2p-band center by 0.44 eV and reduces the average oxygen Bader charge, synergistically mitigating irreversible oxygen release. This atomic-level engineering approach establishes a viable pathway for achieving high activity yet stable oxygen redox in LRMLO cathodes.