Superlattice Engineering Stabilizes Bulk-to-Surface Microenvironment in Single-Crystalline Ultrahigh-Ni Cathodes

Single-crystalline ultrahigh-Ni cathodes hold great promise for high-energy Li-ion batteries, but their practical adoption is hindered by sluggish delithiation kinetics and severe structural degradation. Although superlattice engineering has been established as an effective strategy to stabilize lattice oxygen and enhance Li-ion diffusion in polycrystalline counterparts, realizing ordered Li/Ni anti-site superlattices in micro-sized single-crystalline materials remains challenging, as their formation is largely restricted to the near-surface region. Herein, we report for the first time the construction of a bulk-locally-pinned and surface-even-distributed ordered Li/Ni anti-site superlattice structure in single-crystalline ultrahigh-Ni LiNi_0.93Co_0.02Mn_0.03Al_0.02O₂ cathodes via Mo-induced local microenvironment regulation during high-temperature lithiation. The resulting cathodes exhibit a 32% reduction in Li-ion diffusion energy barrier, a 23% decrease in lattice oxygen loss, and a 26% suppression of c-axis lattice contraction at 90% state of charge. Consequently, these improvements effectively alleviate stress concentration and substantially accelerate delithiation kinetics. The optimized cathode delivers an ultrahigh reversible capacity of 230 mAh g^-1 at 0.1C and achieves a cycle life exceeding 4500 cycles in Ah‑level pouch-type full cells.