Water-aerosol-assisted roasting for selective lithium extraction from spent lithium-ion batteries

Selective extraction of lithium from spent lithium-ion batteries (LIBs) represents a promising solution for efficient lithium recovery. Herein, a water-aerosol-assisted roasting technology is proposed to selectively extract lithium from spent lithium transition metal oxides (LTMOs) cathodes. In an exemplary recycling of spent LiCoO 2 , the cathode material undergoes a low-temperature (350°C) chlorinating roast process to convert it into metal chlorides, followed by a higher-temperature (500°C) roasting to facilitate the selective pyrolysis of CoCl 2 . The presence of water-aerosol significantly enhances the selective pyrolysis process of CoCl 2 , reducing roasting time eightfold compared to conventional air roasting. Subsequent water-leaching effectively extracts 99.1 % of lithium as LiCl, while only 0.2 % of cobalt is extracted, ensuring selective lithium recovery. The resulting high-purity LiCl solution and Co 3 O 4 residue are directly utilizable for producing battery-grade Li 2 CO 3 and LiCoO 2 , respectively. Regenerated LiCoO 2 demonstrates excellent cycling stability, retaining 90.5 % of its capacity after 300 cycles at 1C rate. Moreover, this method is applicable to ternary cathodes (NCM) black mass, offering a sustainable, robust, and cost-effective approach for lithium extraction from spent LIBs.