Anchoring Ligand Electron Enables Robust Metal‐Oxygen Coordination Toward 4.5 V O3‐Type Sodium‐Ion Battery Cathodes

(NFM) as a model system, we identify the origin of this instability as a detrimental feedback loop between σ-type oxygen redox and cation migration. We thus propose an "anchoring ligand electron (ALE)" strategy, employing a multi-level screening protocol to identify optimal anchor agents that confine oxygen redox to stable π-type configurations with robust metal-oxygen coordination. The ALE-engineered NFM cathode mitigates excessive oxygen ligand electron transfer, achieving record capacity retention at an ultrahigh voltage of 4.5 V after 300 cycles. The superior cyclic stability is demonstrated to be closely associated with the stable π-type oxygen redox and suppressed metal-oxygen decoordination. This ALE strategy expands the optimization pathway toward ultrahigh-voltage and high-energy-density cathodes.