Upcycling of Spent LiNi<sub>0.33</sub>Co<sub>0.33</sub>Mn<sub>0.33</sub>O<sub>2</sub> to Single-Crystal Ni-Rich Cathodes Using Lean Precursors
Hongpeng Gao, Qizhang Yan, Duc Tran, Xiaolu Yu, Haodong Liu, Mingqian Li, Weikang Li, Junlin Wu, Wei Tang, Varun Gupta, Jian Luo, Zheng Chen
Abstract
Lithium-ion batteries (LIBs) are widely applied in portable electronics, electric vehicles (EVs), and grid storage systems. They need sustainable end-of-life battery management to reduce greenhouse emissions and resource consumption to create a low-carbon future. Here, we report an efficient upcycling method, converting spent polycrystalline LiNi 0.33 Co 0.33 Mn 0.33 O 2 (NCM111) up to single-crystal LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) with lean input of precursors. A systematic investigation of the microstructure evolution in the upcycling process revealed an Ostwald ripening phenomenon during the particle transformation. Optimizing the sintering temperature and reaction time results in single-crystal particles showing uniform Ni element distribution and valence state, clean surface, and tunable sizes. Particularly, these structural features endow upcycled NCM811 with improved performance (198 mAh/g at C/10 and 173 mAh/g at 1 C) compared to commercial polycrystals while maintaining good cycling stability. This work demonstrates a feasible pathway toward affordable and efficient upcycling in today’s sustainable development of NCM cells, which paves the way for the next-generation LIB recycling and upcycling.