Layered nickel-rich oxides, Li(Ni x Co y Mn 1 –x–y )O 2 ( x  ≥ 0.6), exhibit a high reversible capacity of over 200 mAh/g, ranking as one of the greatest attractive cathode materials for lithium-ion batteries. Nevertheless, their performance stability decreases with increasing Ni content, and conventional synthesis methods are difficult to control the lattice order, resulting in poor cyclic performance. To address above issues, this study aims skillfully to utilize CH 3 COOLi as the secondary lithium source combining with LiOH obtaining high-performance Li(Ni 0.8 Co 0.1 Mn 0.1 )O 2 single crystalline cathode material by a comparatively lower temperature solid-state route. The synthesized single crystal materials are represented by XRD, SEM, TEM, XPS, and electrochemical means to analyze physicochemical characteristics, along with benefits of CH 3 COOLi, are discussed. The research findings demonstrate that uniform particle size distribution with regular morphology, intact crystal structure, and relatively high level of crystallinity can be achieved without damage after sintering under the described conditions. The material exhibits a specific capacity of 205 mAh/g at a rate of 0.2 C, as well as retention of 92.68% after 100 cycles at 25 °C. This investigation offers new perspectives into the synthesis and application of single-crystal Ni-rich cathode materials, revealing valuable references for enhancing the performance of lithium-ion batteries.