Recovery of Li and Co from Spent Li-Ion Batteries by Mechanochemical Integration with NH4Cl

Green, efficient, and cost-effective methods of recycling lithium (Li) and cobalt (Co) metals from lithium-ion batteries (LIBs) have attracted increasing attention. This study proposes the use of an NH4Cl-acid leaching system to recover Li and Co metals from spent lithium cobalt oxide (LCO) batteries through mechanochemical activation. The reductive leaching mechanism of Li and Co metals in the mechanochemical-NH4Cl-acid leaching system was explored through the study of the ball milling time, ball milling speed, acid concentration, NH4Cl concentration, leaching temperature, leaching time, solid-liquid ratio, and it was successfully employed. The characterization of the leaching residue was used to identify the leaching reaction mechanism, and the fitting of different kinetic models determined the leaching kinetics. Compared with the traditional acid leaching method, the leaching efficiencies of Li and Co increased from 66.38% and 32.96%, respectively, to 100% and 99.22%, respectively, following the leaching of LCO via mechanochemical activation in extremely low solubility NH4Cl and an acid solution for 120 min. This study proposes a leaching method that is more cost-effective, efficient, and environmentally friendly than traditional acid leaching methods for recycling Li and Co from spent LCO batteries.