An environmental friendly attempt to recycle the spent Li-ion battery cathode through organic acid leaching

Abstract

An environmentally friendly hydrometallurgical leaching process for the recovery of metal ions from the cathode active materials of spent lithium-ion batteries was investigated. The spent LIBs were first dismantled and separated by physical separation. The powder obtained after physical separation was subjected for leaching using easily degradable organic acids like nitrilotriacetic acid, adipic acid, and ascorbic acid. The leaching proceeds with a reductive-complexing mechanism and leaching occurs in about 6 h. The leaching rate constants (k) for Li and Co ions were determined by ‘cubic rate law’ plots. The formation of Co(III)– to Co(II)–Ligand during the leaching is confirmed from the UV–Vis spectra. The structural, morphology of the cathode materials before and after leaching was characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The amount of lithium and cobalt present in the leachate was determined by atomic absorption spectrophotometry (AAS). The presence of ascorbic acid in adipic acid solution is an active reducing agent compared to ascorbic acid in nitrilotriacetic acid solution because it enhances the leaching efficiency.