Abstract The recycling of spent lithium-ion batteries remains a challenging task due to the complexity of the leach liquors, which contains several metals in acidic solution. The recovery of valuable metals, viz. Co, Li, Mn, Ni, is also difficult due to the similar chemical behavior of the divalent metal ions. Solvent extraction is mainly used for the separation of these metals, but the conventional extractants used in combination with molecular diluents usually lack of selectivity. We report a new solvent extraction system based on N,N,N',N'-Tetra-n-octyldiglycolamide (TODGA) diluted in the room temperature hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Up to 99% of manganese can be extracted in one step with separation factors in the range 40–60 for Mn/Co separation and higher than 200 for the other metals. The mechanism of extraction was detailed. Cobalt separation was done using the ionic liquid tri-hexyltetradecylphosphonium chloride. More than 90% of cobalt can be extracted with very high separation factors. Nickel and lithium separation was carried out by deep eutectic solvents (DESs) based on lidocaine and carboxylic acids. The use of a DES made of decanoic acid and lidocaine shows a high extraction efficiency for nickel while lithium is left in solution.

中文翻译：

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使用离子液体和低共熔溶剂对锰、钴、镍和锂进行溶剂萃取分馏

摘要 由于浸出液的复杂性，废锂离子电池的回收仍然是一项具有挑战性的任务，浸出液在酸性溶液中含有多种金属。有价金属的回收，即。由于二价金属离子的化学行为相似，Co、Li、Mn、Ni 也很难。溶剂萃取主要用于这些金属的分离，但与分子稀释剂结合使用的常规萃取剂通常缺乏选择性。我们报告了一种基于 N,N,N',N'-Tetra-n-octyldiglycolamide (TODGA) 在室温疏水性离子液体 1-丁基-3-甲基咪唑鎓双（三氟甲基磺酰）亚胺中稀释的新溶剂萃取系统。一步可提取高达 99% 的锰，Mn/Co 分离的分离系数在 40-60 之间，其他金属的分离系数高于 200。详细介绍了提取机制。使用离子液体三己基十四烷基氯化鏻进行钴分离。90% 以上的钴可以通过非常高的分离系数被提取出来。镍和锂的分离是通过基于利多卡因和羧酸的低共熔溶剂 (DES) 进行的。使用由癸酸和利多卡因制成的 DES 显示出镍的高提取效率，而锂则留在溶液中。镍和锂的分离是通过基于利多卡因和羧酸的低共熔溶剂 (DES) 进行的。使用由癸酸和利多卡因制成的 DES 显示出镍的高提取效率，而锂则留在溶液中。镍和锂的分离是通过基于利多卡因和羧酸的低共熔溶剂 (DES) 进行的。使用由癸酸和利多卡因制成的 DES 显示出镍的高提取效率，而锂则留在溶液中。