High-efficiency leaching of Li and Ni from spent lithium-ion batteries based on sodium persulfate

Abstract

Herein, the preferential leaching of Li and Ni from spent lithium-ion batteries was put forward for the first time. Firstly, the stable structure of cathode material was destroyed by reduction roasting, and then Li and Ni in roasted product were leached in sodium persulfate solution. Through adjusting the redox potential and pH of the solution, Li and Ni could exist in the solution in the form of Li+ and Ni2+, while Co and Mn remained in the residue mainly in the form of Co3O4 and MnO2. The leaching efficiencies of Li and Ni were 95.07% and 96.02% under the optimized conditions, respectively. Kinetic analysis showed that the leaching process was controlled by surface chemical reaction. In addition, XPS, XRD, thermodynamic analysis, and SEM-EDS were used to explore the mechanism. This method could effectively simplify the recovery and separation process, providing a new thought for the utilization of spent lithium-ion batteries.