Novel electrochemically driven and internal circulation process for valuable metals recycling from spent lithium-ion batteries.

Abstract

The sustainable recycling of valuable metals from spent lithium-ion batteries (LIBs) is impeded by the issues of extensive chemicals consumption, tedious separation process and deficient selectivity. Here, novel electrochemically driven and internal circulation strategy was developed for the direct and selective recycling of valuable metals from waste LiCoO2 of spent LIBs. Firstly, the waste LiCoO2 can be efficiently dissolved by generated acid (H2SO4) during electro-deposition of Cu from CuSO4 electrolyte. Then, Co2+ ions in the lixivium can be electrodeposited and recovered as metallic Co with a coinstantaneous regeneration of H2SO4 and regenerated acid can be reused as leachant without obvious shrinking of leaching capability based on circulating leaching results. Over 92% Co and 97% Li can be leached, and 100% Cu and 93% Co are recovered as their metallic forms under the optimized experimental conditions. Results of leaching kinetics suggest that the leaching of Co and Li is controlled by internal diffusion with significantly reduced apparent activation energies (Ea) for Li and Co. Finally, Li2CO3 can be recovered from Li+ enriched lixivium after circulating leaching. This recycling process is a simplified route without any input of leachant and reductant, and valuable metals can be selectively recovered in a closed-loop way with high efficiency.