J. Manjanna
Rani Channamma University, India
Title: Recovery of Co and Li from Spent Li-ion Batteries using mild Organic acids
Biography
Biography: J. Manjanna
Abstract
Environmentally benign hydrometallurgical process is investigated for the recovery of Co and Li from the cathode active materials of spent lithium-ion batteries (LIBs). A mixture of chelating agent (L = citric acid, tartaric acid, iminodiacetic acid, maleic acid etc.) and reducing agent (ascorbic acid) are used to dissolve the typical cathode material, LiCoO2 collected from spent LIBs. Almost complete dissolution occurred in each case at 80 °C in about 4 h. The formation of Co(III)ï€ and Co(II)ï€L is evident from the UV-Vis. spectra of the dissolved solution as a function of dissolution time. Thus, the reductive-complexing dissolution mechanism is proposed here. In a typical case of citric acid and ascorbic acid mixture, the dissolution rate constants (k) are 3.1 × 10−3 min−1 for Li and 0.8 × 10−3 min−1 for Co ions as determined by ‘cubic rate law’ plots. The dissolved solution was subjected for selective precipitation of cobalt as Co-oxalate and lithium as LiF using oxalic acid and NH4F, respectively. The reducing agent, ascorbic acid, converts the dissolved Co(III)- to Co(II)-L thereby selective recovery of Co as Co(II)-oxalate is possible. The present study has a merit as we make use of mild organic acids as alternatives to mineral acids.