Dual-effect modification strategy to enhance the thermodynamic stability of high‑nickel single-crystal cathode materials

High‑nickel single-crystal materials hold promise for eliminating grain boundaries and enhancing cycle performance, thereby advancing the development of lithium-ion batteries (LIBs). However, challenges such as cation mixing, poor thermal stability, irreversible phase transition, and serious surface side reactions hinder their commercialization. Hence, we address the above problems by bulk phase Al doping and surface B coating strategies, fabricated the modified cathode LiNi 0.65 Co 0.15 Mn 0.20 O 2 (NCMAB). Benefiting from an excellent dual-effect modification strategy, the cation mixing degree of the NCMAB was effectively controlled, and its cycling performance (25 °C, 1C, 1000 cycles, 82 %) and thermal stability (60 °C, 1C, 250 cycles, 87.6 %) were significantly improved. Notably, visible microcracks and unfavorable phase transitions in the pristine cathode material after cycling were effectively avoided. This further promotes the prospect of high‑nickel single-crystal cathode materials at high temperatures.