ABSTRACT

Failure to recycle valuable metals from lithium-ion batteries (LIBs) could directly lead to various environmental issues, such as ecological toxicity with inevitable impacts on environment and society health. This study presents a green process for selective recovery of Li from spent LIBs based on a ternary deep eutectic solvent. The effects of solid-to-liquid ratio, temperature, and variations of deep eutectic solvent (DES) component concentrations on the selectivity of the leaching process were studied. A ternary DES based on choline chloride, urea and ethylene glycol was found to be more selective than conventional binary DESs and made it possible to extract the Li in the lower temperatures (75–100°C). In such temperatures, DESs present better viscosity and higher stability. In the optimum conditions, 92.83%, 1.61%, 0.72%, and 0.42% recoveries were obtained for Li, Co, Ni, and Mn, respectively. Kinetic modeling indicates that mixed control models were best fitted to all data. Moreover, the results indicated that the activation energy for Li extraction is 21.15 KJ/mol. Pearson correlation assessment relieved that L/S was the most effective factor with a positive impact (r > +0.5) on Li recovery among all variables. Furthermore, temperature impacts the selectivity of the leaching process. The illustrated selectivity coupled with biodegradability and the possibility of re-utilization of the DESs opens a novel way for the greener recovery of values from wastes.

摘要

未能从锂离子电池 (LIB) 中回收有价金属可能会直接导致各种环境问题，例如生态毒性，对环境和社会健康造成不可避免的影响。本研究提出了一种基于三元低共熔溶剂从废锂离子电池中选择性回收锂的绿色工艺。研究了固液比、温度和低共熔溶剂 (DES) 组分浓度变化对浸出过程选择性的影响。发现基于氯化胆碱、尿素和乙二醇的三元 DES 比传统的二元 DES 更具选择性，并且可以在较低温度（75–100°C）下提取锂。在这样的温度下，DES 表现出更好的粘度和更高的稳定性。在最佳条件下，92.83%、1.61%、0.72% 和 0。Li、Co、Ni 和 Mn 的回收率分别为 42%。动力学建模表明混合控制模型最适合所有数据。此外，结果表明，锂提取的活化能为 21.15 KJ/mol。Pearson 相关性评估表明 L/S 是最有效的因素，对所有变量中的锂回收具有积极影响 (r > +0.5)。此外，温度影响浸出过程的选择性。所示的选择性加上生物降解性和 DES 再利用的可能性为从废物中更绿色地回收价值开辟了一条新途径。15 KJ/摩尔。Pearson 相关性评估表明 L/S 是最有效的因素，对所有变量中的锂回收具有积极影响 (r > +0.5)。此外，温度影响浸出过程的选择性。所示的选择性加上生物降解性和 DES 再利用的可能性为从废物中更绿色地回收价值开辟了一条新途径。15 KJ/摩尔。Pearson 相关性评估表明 L/S 是最有效的因素，对所有变量中的锂回收具有积极影响 (r > +0.5)。此外，温度影响浸出过程的选择性。所示的选择性加上生物降解性和 DES 再利用的可能性为从废物中更绿色地回收价值开辟了一条新途径。