The reductant is a critical factor in the hydrometallurgical recycling of valuable metals from spent lithium-ion batteries (LIBs). There is limited information regarding the use of SnCl₂ as a reductant with organic acid (maleic acid) for recovering valuable metals from spent Li-CoO₂ material. In this study, the leaching efficiencies of Li and Co with 1 mol·L⁻¹ of maleic acid and 0.3 mol·L⁻¹ of SnCl₂ were found to be 98.67% and 97.5%, respectively, at 60°C and a reaction time of 40 min. We investigated the kinetics and thermodynamics of the leaching process in this study to better understand the mechanism of the leaching process. Based on a comparison with H₂O₂ with respect to leaching efficiency, the optimal leaching parameters, and the activation energy, we determined that it is feasible to replace H₂O₂ with SnCl₂ as a leaching reductant in the leaching process. In addition, when SnCl₂ is used in the acid-leaching process, Sn residue in the leachate may have a positive effect on the re-synthesis of nickel-rich cathode materials. Therefore, the results of this study provide a potential direction for the selection of reductants in the hydrometallurgical recovery of valuable metals from spent LIBs.

还原剂是从废锂离子电池 (LIB) 湿法冶金回收有价值金属的关键因素。关于使用 SnCl ₂作为有机酸（马来酸）的还原剂从废 Li-CoO ₂材料中回收有价值金属的信息有限。在本研究中，1 mol·L ^-1马来酸和 0.3 mol·L ^-1 SnCl ₂对 Li 和 Co 的浸出效率分别为 98.67% 和 97.5%，在 60°C 和反应时间40分钟。我们在本研究中研究了浸出过程的动力学和热力学，以更好地了解浸出过程的机制。基于与 H ₂ O ₂的比较相对于浸出效率，最佳浸出参数和活化能，我们确定是可行的代替H ₂ ö ₂与的SnCl ₂作为在浸出过程中浸出还原剂。此外，在酸浸过程中使用SnCl ₂时，浸出液中的Sn残留物可能对富镍正极材料的再合成产生积极影响。因此，本研究结果为从废锂离子电池湿法冶金回收有价金属中还原剂的选择提供了潜在的方向。