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

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 (E_a) 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.