Highly‐Dispersed Single‐Crystalline Ni‐Rich Cathodes with Low Li/O Loss for High‐Power and Long‐Life Li‐Ion Batteries

Abstract Highly‐dispersed single‐crystalline Ni‐rich cathodes with low Li/O loss are the key for high‐power Li‐ion batteries, but it is still a big challenge because an additional 60–110 °C higher synthesis temperature is required in comparison with the polycrystalline counterparts. Herein, a highly‐ordered and monodisperse single‐crystalline LiNi_0.83Co_0.12Mn_0.05O₂ (NCM83) cathode with an average size of 3.24 µm is reported by a Sr/Nb synergically controlling the grain surface energy strategy based on the Vegard's slopes of various ions. The solid‐phase lithiation temperature is reduced by ≈80 °C, greatly reducing Li/Ni disorder and oxygen vacancies with rapid Li‐ion diffusion kinetics and high structure stability. The introduced Sr/Nb ions remarkably increase the electron cloud density near the Fermi level, while alleviating the H2‐H3 phase transition with reduced lattice shrinkage. The as‐prepared single‐crystalline NCM83 cathode exhibits obvious increased capacity retention of 60% at 10C (vs. 0.1C) in coin‐type half‐cells and 89% after cycling 1000 times at 0.5C in pouch‐type full‐cells. The work sheds light on the low‐temperature synthesis of monodisperse and uniform single‐crystalline Ni‐rich cathodes for high‐power and long‐life Li‐ion batteries.