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

Using state-of-the-art ultra-high nickel (UHN) layered oxides (LiNi_xCo_yMn_1-x-yO₂, 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 “Ni²⁺ 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 “Ni²⁺ 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.