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 strategies to alleviate the resource shortage, address environmental pollution, and cater to 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 three birds, i.e., lithium supplement, Li2SO4 coating, and Mn doping into Co sites while N, S doping into Li-O slabs are simultaneously hit with one stone (one-pot solid-phase sintering). Benefiting from these favorable characteristics, the upcycled cathode not only yields high discharge-specific capacity of 188.2 mAh g(-1) at 0.2 C, but also delivers superior cycling performance with 92.5% of capacity retention after 100 cycles (86.4% after 300 cycles) at 0.5 C and excellent rate capability at a high cutoff voltage of 4.5 V, superior to a 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.