Homogenized Upcycling for Spent LiNi 0.5 Co 0.2 Mn 0.3 O 2 : Modulating O Vacancies toward Enhanced Structural Stability

Abstract Fascinated by the high value and low pollution, the direct recycling of spent LiNi 0.5 Co 0.2 Mn 0.3 O 2 (S‐NCM) has triggered plenty of exploring activities. Considering different industry sources, they always display various particle sizes and surface traits. Therefore, the simple recovery of chemical defects hardly meets the market demand. Herein, the homogenized strategy, containing physical crushing and chemical recovering, is introduced to regenerate morphology and components of S‐NCM, where the successfully regenerated samples displayed uniform particle size and stable chemical lattice. Assisted by physical crushing, the precursors show a large contacting area with oxygen during morphology reconstruction, accompanied by the effective repairing of the internal lattice. More significantly, the unique manner induces the repairing of oxygen vacancies (OVs) and the lowering of Li/Ni disorder, bringing about enhanced structural stability. Moreover, the lowering of oxygen redox activity and the improvement of oxygen binding energy are further revealed by theoretical calculations. The as‐optimized regenerated samples display a considerable capacity of 139.6 mAh g −1 with a remarkable capacity retention of 94% at 1.0 C. Even at 5.0 C, its capacity retention could be kept at ≈80.8% after 150 loops. Given this, this work is expected to provide effective guidance for different NCM regenerations, meanwhile offering an in‐depth understanding of morphology/lattice reconstruction.