Anchoring Nickel and Stabilizing Oxygen in Coherent LiNiO2@LiFePO4 Composite Cathode Materials for Rechargeable Lithium‐Ion Batteries

Abstract LiNiO 2 is an appealing cathode material for Li‐ion batteries because of high energy density and low cost but suffers from irreversible phase transition and surface instability. Herein, a ball‐milled LiNiO 2 @LiFePO 4 composite with oriented coherent combination is reported with enhanced structural stability and Li + diffusion. The coherent oriented channels are demonstrated to favor the reversible and rapid Li + intercalation during the H2‐H3 phase transition, which significantly alleviates structural strain accumulation. The covalent P─O bonds anchored on the LiNiO 2 surface stabilizes the Ni sites, mitigating surface reconstruction and lattice oxygen loss. The LiNiO 2 @LiFePO 4 cathode exhibits a specific capacity of 210 mAh g −1 and an initial Coulombic efficiency of 93.7% at 0.1 C, along with a remarkable rate capability of 156 mAh g −1 at 10 C. Furthermore, the full cells pairing LiNiO 2 @LiFePO 4 cathode and graphite anode deliver a considerable energy density over 280 Wh kg −1 and a remarkable capacity retention. This study offers an effective approach of phosphate coalesce to upgrade high‐capacity nickel‐rich oxide cathode materials.