Upcycling of Spent LiNi0.33Co0.33Mn0.33O2 to Single-Crystal Ni-Rich Cathodes Using Lean Precursors

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 LiNi0.33Co0.33Mn0.33O2 (NCM111) up to single-crystal LiNi0.8Co0.1Mn0.1O2 (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.