Selective Recovery of Cobalt and Fabrication of Nano-Co3S4 from Pregnant Leach Solution of Spent Lithium-Ion Batteries

摘要

These days, innovative ideas in converting wastes to value-added materials are a solution for the fast-growing environment hazards of lithium-ion batteries (LIBs). The present paper introduces a novel method for synthesizing Co3S4 nano-powders from the pregnant leach solution (PLS) after acidic leaching of LIBs. For the first time, the cobalt along with nickel ions was selectively extracted from the PLS by a xanthate complex at room temperature. Then, the complex was washed with ammonia solution to obtain a pure cobalt complex. Finally, the complex was converted to uniform and pure nano-spheres of Co3S4 through a comparatively mild heat treatment (250 degrees C for 1 h). Characterization techniques (X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analyses) revealed high purity of the nano-architectures. Thermal analysis (TG-DSC) also confirmed the single phase of pure Co3S4 nano-articles, while the mean particle sizes were obtained 48 nm and 40 +/- 2 nm using XRD and transmission electron microscopy (TEM) analyses, respectively. Plus, the presence of high specific surface area (36.42 m(2)/g) using BET analysis for this nano-powder is in complete agreement with the electrochemical studies in which a relatively high insertion peaks (1.14 V) were observed for the first cycle of cyclic voltammetry and (1.00 V) for the seventh cycle (equilibrium cycle). Finally, we believe that the presented approach and its results can open up new avenues to the recycling industry of LIBs.