Cobalt and lithium leaching from waste lithium ion batteries by glycine

Waste lithium-ion batteries (LIBs) contain cobalt, lithium, and other valuable materials, which attracts the attention of a large number of researchers. Taking effective measures not only reduced environmental pollution but also maximizes economic benefits. In this work, an effective and environmental-friendly approach for leaching cobalt and lithium from LIBs by a green glycine was developed. The leaching rates of Co and Li were respectively 97.07% and 90.95% (300 g/L glycine, 10% H2O2, solid/IL ratio of 1:100, 353 K, 7 h). The results of leaching kinetics show that the leaching process is controlled by interfacial chemical reactions, and the activation energy of Co and Li is respectively 78.57 kJ mol(-1) and 56.20 kJ mol(-1). In addition, scanning electron microscopy (SEM) and x-ray diffraction (XRD) were applied to analyze the morphology and phase composition of waste LIBs before and after leaching, and the XRD results prove the leaching of LiCoO2 since its peak intensity decreased greatly, which indicated the decomposed of LiCoO2 after leaching. Therefore, the use of glycine, a green extractant, does not only result in a higher leaching efficiency, but also reduces the use of inorganic acids, providing a novel approach for the green recovery of waste LIBs in the future.