Spray pyrolysis technology-based closed-loop for regenerating single-crystal cathodes from spent lithium-ion batteries

Recycling of spent Li-ion batteries (LIBs) is an emerging global concern. Current recycling technologies generally include multiple purification operations and involve the use of lots of chemicals, which compromise their competitiveness in terms of both economic and environmental benefits. Herein, we propose a spray pyrolysis technology-based closed-loop for regenerating single-crystal cathodes from spent LIBs, which could simultaneously achieve the separation of Li and transition metals (TMs) and obtain high-quality precursors for the synthesis of single-crystal cathodes. As an exemplary study, spent LiCoO2 is first converted into chlorides through a chlorination process. More than 95% of Li is selectively leached out by the "spray pyrolysis-water leaching" process. Simultaneously, the Co3O4 leaching residue could be directly used as a precursor for synthesizing high-performance single-crystal LiCoO2, while the gaseous HCl produced in the pyrolysis process could be recycled in the chlorination process. Therefore, this closed-loop of Li, Co, and Cl holds great economic benefits as it gets rid of the complicated purification operations and precursor preparation processes (such as coprecipitation), opening a new avenue for LIBs recycling.