Recovery of lithium and cobalt from waste lithium-ion batteries through a selective isolation-suspension approach

This paper describes a selective thermal isolation-suspension process for the recovery of Li and Co from spent Lithium-ton Batteries (LIBs). The cathodic part of LIBs, which are mainly composed of Li, Al and Co, sourced from electronic waste (e-waste) was first subjected to a suspension stage for removing Al. XRD analysis of the cathodic sample free of Al (C1) revealed that C1 was in the form of LiCoO2. Thermal behavior of C1 was also examined against time and temperature using Thermogravimetric Analysis (MA). Thermal isolation of C1 was carried out via reduction in argon atmosphere using activated carbon at temperature in the range of 600 degrees C to 800 degrees C for 30 min. Al 600 degrees C, no dissociation of the initial compound of LiCoO2 was observed. At 800 degrees C Li totally liberated from the sample in form of gas and cobalt oxide was reduced to the metallic cobalt. However, at 700 degrees C, Li was thermally isolated in form of solid lithium carbonate and separated from Co. Temperature of 700 degrees C was selected as the optimum temperature for thermal isolation of Li which resulted in dissociation of LiCoO2 into Co, CoO and Li2CO3. After thermal isolation at 700 degrees C, the resulting mixture (C2) was dispersed into distilled water, placed in a cold-water bath with temperature of 0 degrees C and was allowed to gradually dissolve in water for 1 h. After filtration and washing using a centrifuge, the solution was subjected to ICP analysis and the undissolved particles were dried in an oven overnight prior to further reduction at 700 degrees C for full reduction of cobalt oxide to metallic cobalt The simple and environmentally friendly approach proposed in this work for the recovery of Li and Co from spent LIBs can potentially help in addressing the problems associated with waste LIBs and depletion of natural resources. (C) 2019 Elsevier B.V. All rights reserved.