Architecturally Inspired Lattice Engineering Enables Long‐Life Ultra‐High Nickel Cathodes

Abstract Using state‐of‐the‐art ultra‐high nickel (UHN) layered oxides (LiNi x Co y Mn 1‐x‐y O 2 , x≥0.9) as battery cathodes is expected to push the boundaries of energy density. However, their structural instability, particularly the H2–H3 phase transition, drives rapid capacity fading. Here, a structural modulation strategy inspired by architectural mechanics is presented: a simple candle soot coating followed by thermal annealing induces a mortise‐like disordered surface phase and stabilizing “Ni 2+ columns” within Ni94 cathode. These features synergistically suppress intergranular stress and mitigate the H2–H3 phase transition. As a result, 4.5V‐Graphite||Ni94 pouch cell retains 80.2% of their capacity after 2000 cycles. STEM and operando electrochemical analysis, supported by DFT calculations, reveal the role of “Ni 2+ columns” in stabilizing the layered framework. This work introduces a novel approach to lattice engineering in ultra‐high nickel cathodes, offering a practical pathway toward long‐life, cobalt‐lean lithium‐ion batteries.