Study on the carboreduction of the cathode material present in spent LIBs to produce Li2CO3 and CoO

Abstract

The recycling of value metals from spent lithium-ion batteries (LIBs) have interesting benefits such as reduction of natural resources exploitation and minimization of energy consumption from mining operations. The aim of this work was to recover lithium, cobalt and manganese from the cathode material present in spent LIBs through a pyrometallurgical process of carboreduction. The method consisted in mixing the cathode material with carbon black and a subsequent heat treatment of the mixture under nitrogen atmosphere. The products obtained were separated by water leaching. To elucidate the reactions and the mechanism involved in the carboreduction process, different studies involving thermodynamic calculations, thermal gravimetric analysis (TGA), differential thermal analysis and X-ray diffraction (XRD) were carried out. The results indicated that Li2CO3, CoO and MnO are produced at temperatures lower than 600 °C. The results of atomic absorption spectrometry (AAS) showed that the extraction percentage of lithium was greater than 90% at temperatures between 550 and 600 °C. The products obtained through the process presented here could be used in either the manufacture of new batteries or other industrial applications.