Recycling cathode material LiCo1/3Ni1/3Mn1/3O2 by leaching with a deep eutectic solvent and metal recovery with antisolvent crystallization

Deep eutectic solvents (DESs) have been proposed as green alternatives for recycling lithium-ion battery (LIB) cathode materials. In the present work, a sustainable DES based on choline chloride and L-(+)-tartaric acid has been systematically investigated for leaching of a LIB cathode material (LiCo1/3Ni1/3Mn1/3O2) for the first time. Moreover, in a novel approach, antisolvent crystallization has been applied to recover metals from the DES leachate. The L-(+)-tartaric acid-based DES shows a good leaching capacity and a high leaching rate at 70 °C. Furthermore, antisolvent crystallization is shown to enable a high metal recovery efficiency of cobalt, nickel and manganese (>98.5%). The precipitate from antisolvent crystallization can be used as a precursor for the synthesis of new cathode material, while the remaining DES and antisolvent can be recovered for reuse in the process. This work presents a green, effective and closed-loop metal recovery strategy for recycling LIB cathode materials using a sustainable DES.