An atom-economic process for the recovery of high value-added metals from spent lithium-ion batteries

Abstract

With the surge of spent lithium-ion batteries (LIBs) generated worldwide, resource utilization of these exhausted batteries will be desiderated to alleviate the resource depletion and environmental pollution. Herein an atom-economic process combined with reductive leaching and selective precipitation was explored to recover valuable metals from waste cathode materials of spent LIBs in this study. Waste cathode materials were firstly dissolved using citric acid and d-glucose as leachant and reductant, respectively. About 99%, 91%, 92% and 94% Li, Ni, Co and Mn could be leached under the following optimized conditions: retention time – 120 min, reaction temperature – 80 °C, concentration of citric acid – 1.5 mol/L, pulp density – 20 g/L and reductant dosage – 0.5 g/g. High value-added metals were then separated and recovered by selective precipitation method. It was also discovered that the residual leachate after metals recovery can be re-utilized as leaching reagent with potentially excellent performance as fresh leachant. In addition, the leaching and precipitation mechanism was also tentatively investigated in terms of glucose oxidation pathway and materials recovery. Finally, atom utilization efficiency was calculated and the atom utilization efficiency can achieve as high as 98% for the whole recovery process. Both experimental and theoretical results obtained can support a sustainable and desirable process for a comprehensive recovery of metal values from spent LIBs in a closed-loop manner.