Direct upcycling of degraded LiCoO${}_2$ material toward high-performance single-crystal NCM cathode

The growing volume of spent lithium-ion batteries (LIBs) with degraded LiCoO${}_2$ (D-LCO) cathodes is arising as an environmental concern as well as a waste of strategic resources. Current recycling strategies for D-LCO materials primarily focus on metal extractions (Li and Co), which produce large quantities of wastewater and waste residues and consume substantial amounts of energy. Inspiringly, the rapid proliferation of electric vehicles has catalyzed the ever-increasing production of LIBs with ternary layered oxides as the prevalent cathode materials. Herein, this work reports a simple, green, and economic upcycling strategy for direct transformation of D-LCO into high-performance single-crystal LiNi${}_{1/3}$Co${}_{1/3}$Mn${}_{1/3}$O${}_2$ (NCM111) cathode materials. By simultaneous lithium replenishment, particle size reduction, and chemical composition engineering in the upcycling process, the NCM111 product delivers a high specific capacity (159.0 mAh g${}^{-1}$ at 0.1 C) and an excellent cycling stability (82.1% retention after 200 cycles at 1 C), outperforming those of commercial materials. This work highlights the immense potential of upcycling strategies in mitigating the environmental ramifications of spent LIBs and paves the way for the sustainable development of LIBs industry. (© 2024 Wiley‐VCH GmbH)