Recovery of Lithium, Nickel, Cobalt, and Manganese from Spent Lithium-Ion Batteries Using L-Tartaric Acid as a Leachant

Herein is reported a novel green process involving natural L-tartaric acid leaching, developed for the sustainable recovery of Mn, Li, Co, and Ni from spent lithium-ion batteries (LIBs). Operating conditions affecting the leaching efficiencies of Mn, Li, Co, and Ni, including the concentrations of L-tartaric acid (C4H6O6) and hydrogen peroxide (H2O2), pulp density, temperature, and leaching time, were investigated. The leaching efficiencies were 99.31% for Mn, 99.07% for Li, 98.64% for Co, and 99.31% for Ni under the optimized conditions (4 vol% H2O2, 2 M L-tartaric acid, 17 g/L pulp density, 70 degrees C, and 30 min). The leaching mechanism was studied preliminarily based on the structure of L-tartaric acid. The kinetics data for the leaching of Mn, Li, Co, and Ni fit best to the shrinking-core model of chemical control. For the first stage, the activation energies (E(a)s) for the leaching of Mn, Li, Co, and Ni were 66.00, 54.03, 58.18, and 73.28 kJ/mol, respectively. For the second stage, the E(a)s for the leaching of Mn, Li, Co, and Ni were 55.68, 53.86, 58.94, and 47.78 kJ/mol, respectively. The proposed hydrometallurgical process was found to be simple, efficient, and environmentally friendly.