Facet‐Stacking Coupling Accelerates Grain Growth During Synthesis of Single‐Crystal Ni‐Rich Cathodes

Abstract Grain growth induced by ions migration is crucial for the preparation of high‐performance single‐crystal Ni‐rich cathodes, which is closely related to the primary particle characteristics. However, the impact of these factors on ion migration is not clearly revealed. Herein, the grain fusion mechanism and its controlling factors, including the size, crystal plane exposure, and stacking configuration of primary particles, are systematically investigated. The results demonstrate that the primary particles with low {010}‐plane‐exposed and high [001]‐oriented stacking nanosheets accelerate grain growth and promote particle dispersion, owing to the reduced active planes minimizing lithium insertion, the retained molten salt filling intergranular gaps to enhance interfacial contact, and the lower ion migration energy barrier on (003) surfaces caused by oxygen coordination delocalization facilitating ion transport. This work provides new insights into the preparation of high‐performance single‐crystal Ni‐rich cathodes.