Surface to Bulk Synergetic Modulation of Nickel‐Rich LiNi_0.83Co_0.06Mn_0.11O₂ via a Three‐in‐One Approach for Long‐Cycle Lithium‐Ion Batteries

Abstract Nickel‐rich cathode materials have gained popularity in the development of lithium‐ion batteries (LIBs) due to their high energy density, which exceeds 250 Wh kg⁻¹. However, the instability of bulk and surface structures has significantly limited their industrial application. In this study, a three‐in‐one approach to synergistically modulate the structure of LiNi_0.83Co_0.06Mn_0.11O₂ (NCM83) from surface to bulk by a phytic acid (PA) coating is proposed. This surface treatment leads to the spontaneous formation of an amorphous lithium phosphates coating layer on the outermost surface, a reconstructed NiO layer at the subsurface, and a gradient P doping in the NCM83 bulk. The resulting hierarchical and multifunctional structure provides a facilitated surface Li‐ion conduction, a NiO‐stabilized subsurface with strong resistance toward side reactions between the electrode and electrolyte, a fast Li ion bulk diffusion endowed by the enlarged LiO₆ slab due to the P doping, and an enhanced H2−H3 phase transition reversibility. As a result, the PA‐NCM83 sample exhibits excellent capacity retention with 72.4% after 300 cycles at 1 C within 2.8–4.45 V, and 69.8% after 200 cycles at an elevated temperature of 45 °C. This approach provides a facile and efficient method to stabilize Ni‐rich cathode materials for next‐generation high‐energy LIBs.