Upcycling of Degraded Licoo2 Cathodes into High-Performance Lithium-Ion Batteries Via a Three-in-One Strategy

Faced with the forthcoming tide of retired lithium-ion batteries (LIBs), it is imperative to explore effective regeneration and upcycling strategy to alleviate the resource shortage, address environmental pollution, and cater the demand for high-energy-density cathode materials. Herein, a facile, non-constructive, one-stone-for-three-birds solid-phase sintering strategy is proposed to regenerate the degraded LiCoO2 (D-LCO) cathode and even upgrade its stability at high voltages, in which lithium supplement, surface reconstruction from Li2SO4 coating, and Mn, N, S co-doping into Co sites are simultaneously achieved. Benefiting from these favorable characteristics, the upcycled cathode not only yields high discharge specific capacity of 213.7 mAh/g at 0.2 C, but also delivers superior cycling performance with 92.5% of capacity retention after 100 cycles at 0.5 C and excellent rate capability at a high cutoff voltage of 4.5 V, superior to the freshly commercial counterpart. This work is expected to provide meaningful guidance for the upcycling of D-LCO into high-energy-density batteries with long-term cycling stability.