Co recovery from spent Li-ion battery by acid leaching - a comparative study

We investigated and compared leaching processes with different acids for the recovery of cobalt from the cathode active materials of spent lithium-ion batteries. The active substances separated from the cathode of spent lithium-ion batteries were dissolved in each acid solutions, and precipitated as CoC2O4•2H2O. The structural morphology of the cathode materials before and after leaching were characterised by X-ray diffraction (XRD). The amount of Co present in the leachate was determined by atomic absorption spectrophotometry (AAS). The experimental study shows that 93% of Co (mass fraction) can be dissolved in the solution of 1.5 M HCl, 2.0% H2O2(volume fraction), and S:L of 20 g/L−1results the highest efficient recovery within 60 min at 90°C comparing other acids in this study.