Hydrometallurgical recycling of valuable metals from spent lithium-ion batteries by reductive leaching with stannous chloride

A reductant counts for much in the hydrometallurgical recycling of valuable metals from spent lithium-ion batteries (LIBs). There is limited information about SnCl₂ as a reductant with organic acid (maleic acid) to recover value metals from spent LiCoO₂ material. The leaching efficiencies were 98.67% and 97.59% for Li and Co with 1 mol L^-1 of maleic acid and 0.3 mol L^-1 of SnCl₂ at 60°C and 40 min. And the kinetics and thermodynamics of the leaching process were inquired in the article to study the mechanism of leaching process clearly. According to the comparison of H₂O₂ on the leaching efficiency, optimal leaching parameters and the activation energy, it is feasible to replace H₂O₂ with SnCl₂ as a leaching reducer in the leaching process. In addition, when SnCl₂ is used in the acid-leaching process, Sn residue in leachate may has a positive effect on the re-synthesis of nickel-rich cathode materials. Therefore, the present study can provide a new direction for reductants selection for the hydrometallurgical recovery of valuable metals from spent LIBs