Multiscale yttrium-stabilized pillaring and fluorinated interphase engineering enable fast Mn redox toward 5C-level layered sodium oxide

P2-type layered oxide cathode possesses great potential for sodium (Na)-ion batteries due to its high capacity and cost effectiveness. However, its practical utilization has been impeded by structural degradation, sluggish reaction kinetics, and interfacial side reactions. Herein, a synergistic strategy is adopted, involving yttrium (Y) pillar doping and methyl (2,2,2-trifluoroethyl) carbonate‌ (FEMC) electrolyte additive, to realize 5C-level Na_0.67MnO₂ cathode (denoted as NMYO-FEMC) with highly exposed {010} active facets and high interfacial stability. It is found that atomic-scale Y doping not only expands the interlayer spacing by 0.12 Å, exposing more {010} active facets, but also activates reversible Mn redox reactions through localized electron redistribution. Moreover, FEMC additive, forming a hybrid structure with propylene carbonate solvent, induces a thin yet robust fluorinated interphase to inhibit Mn dissolution and structural collapse. As a result, the optimized NMYO-FEMC cathode shows a high capacity of 113.9 mAh g⁻¹ with 82.8 % retention after 300 cycles at 5C, and also maintains an enhanced cycling stability even at high-temperature (55 °C). Most impressively, the fabricated NMYO-FEMC||hard carbon full cell realizes superior cycling stability with 84.7 % retention after 100 cycles and rate capability. This work elucidates the multi-scale influence mechanism of atomic doping on crystal structure and the crucial role of electrolyte additives in enhancing interfacial stability of layered oxide materials.