Recovery of lithium and cobalt from spent Lithium- Ion batteries using organic aqua regia (OAR): Assessment of leaching kinetics and global warming potentials

Lithium ion batteries (LIBs) are increasingly used in electrical products and are anticipated to generate 4 million metric tons of waste or spent LIBs globally from 2015 to 2040. To protect the environment and also recover valuable materials, such as lithium (Li) and cobalt (Co), our research employed an ultrasonication assisted hydrometallurgy process and demonstrated the leaching process of spent LIBs in Organic Aqua Regia (OAR) which could efficiently extract Li and Co ions after optimization of multiple factors such as leaching temperature, H2O2 dose, and pulp density. The leaching efficiency of 99% and 94% for Li and Co were obtained with a leaching rate of 0.0016 and 0.013 mg•mg−1•h−1, respectively, which are higher than those obtained with two common acid leachants, nitric and citric acids. To explore the leaching kinetics mechanisms, a multiple-factor formula was established to enable the prediction or the Monte Carol simulation of certainties in leaching efficiencies. Furthermore, our life cycle assessment (LCA) indicates that OAR elicits a similar global warming potential with nitric acid but much lower than citric acid in the leaching unit mass of Li or Co from spent LIBs