Reinforcing Particle Architectural Stability of Li-Rich Cathode With Enhanced Anionic Redox Reaction Reversibility

Lithium-rich layered oxides (LRLOs) promise exceptional energy densities (∼1000 Wh kg^-1) but suffer from coupled structural and chemical instabilities that impede their commercialization. While atomic scale regulation of anionic redox reaction (ARR) reversibility has been extensively explored, the mesoscale architectural degradation, which is exacerbated by detrimental porous structures inherited from precursors, remains critical yet overlooked. Herein, a cross-scale synergistic strategy was introduced to simultaneously reinforce the mesoscale particle architecture and stabilize the atomic-scale charge compensation in LRLOs. By incorporating fluorine to modulate the local electronic environment, the surface energy of the active (010) facets is selectively lowered, driving a profound morphological transformation of primary particles from plate-like to equiaxed. This thermodynamic reconstruction effectively disrupts the adverse precursor-inherited porosity, yielding highly compact secondary particles with accelerated Li⁺ diffusion kinetics. Simultaneously, at the atomic scale, the strengthened transition metal-oxygen (TM-O) covalency suppresses excessive oxygen activation, thereby enhancing reversibility of the ARR. Benefiting from this synergistic architectural and chemical modulation, the cathode exhibits a 6.8% increase in Coulombic efficiency and delivers exceptional long-term stability with capacity retention of 88.8% after 950 cycles. For Ah-level full cells, 96.3% of reversible capacity after 1500 cycles under high-voltage is achieved.