Lattice‐Bound Phosphorization Strategy Enables Long‐Term Cycling of High‐Voltage Sodium‐Ion Layered Oxide Cathode

ABSTRACT Fe‐based layered oxides cathode are highly promising cathode materials for high‐energy‐density sodium‐ion batteries, but their practical application is limited by voltage decay and structural degradation caused by uncontrolled lattice phase transitions (such as lattice oxygen escape and cation migration). Herein, we proposed a lattice‐bound phosphorization strategy that modulates the local environment of lattice oxygen and TM ions by implanting P‐atoms to regulate the surface, interface, and bulk phases. Specifically, the implantation of P‐atoms enhances the coordination interactions between ligands and anions as well as metal ions, thereby effectively suppressing lattice oxygen escape and TMO 6 octahedral distortion during the cycling process. Furthermore, the polyatomic interactions driven by lattice bonds intensify the hybridization of the Fermi level, thereby complicating the migration of sodium ions during the anion redox process. In parallel, the in situ formed amorphous coating layers provide high‐quality interface stability for the layered cathodes. Eventually, the corresponding P‐atoms implanted cathode (abbreviated as O3‐ p ‐NFNM) demonstrates an exceptional capacity retention of 74.2% at 0.5 C after 150 cycles, an outstanding rate capability of 59 mAh g −1 at 5 C, along with excellent dynamics and thermal stability. Clearly, the lattice‐bound modification strategy offers a “full‐featured” solution for sodium‐ion layered cathodes.