Mechanochemical Process Enhanced Cobalt and Lithium\nRecycling from Wasted Lithium-Ion Batteries

Abstract

Cobalt\n(Co) and lithium (Li), rare and valuable elements, are mainly\nused to prepare lithium cobalt oxide (LiCoO₂) for applications\nin lithium-ion batteries (LIBs). Developing an effective method to\nrecover Co and Li from the waste LIBs is of great significance. In\nthe present study, Co and Li were extracted from pure LiCoO₂ powders and the extracted cathode materials powders from the waste\nLIBs after acid dissolution via a mechanochemical reduction process\nwith iron powders. For pure LiCoO₂ powders, the effects\nof Fe to LiCoO₂ mass ratio, rotation speed, and mechanochemical\nreduction time were examined. These parameters influenced positively\nthe extraction of Co, while they showed negligible effects on the\nleaching of Li. The X-ray diffraction (XRD) and scanning electron\nmicroscope (SEM) analyses indicated a promoted extraction of Li arising\nfrom the reduction of particle sizes, magnification of specific surface\narea, and change of the crystal structure of particles. For high-efficiency\nleaching of Co by the mechanochemical reduction process with iron\npowders, X-ray photoelectron spectroscopy (XPS) analysis indicated\nthe changes in the valence state of Co. The actual cathode materials\ndisassembled from the wasted LIBs pretreated by this novel mechanochemical\nreduction process were also explored. The results indicated that the\nleaching ratios of Li, Co, Mn, and Ni could reach 77.15%, 91.25%,\n100%, and 99.9%, respectively. This novel mechanochemical process\nwould be of great importance for the recovery of valuable metals from\nwaste LIBs.