In view of the complex problems for the ionic liquids (ILs) recovery with the system containing ILs and TBP, this work proposed a NaNTf₂-based synergistic extraction system, NaNTf₂ + TBP, which could realize the effective reutilization of the extraction system without reducing the lithium separation ability. Under the optimal extraction parameters, the extraction efficiency of Li⁺ exceeded 98%, while that of Mg²⁺ was only ~1%. The results of mass spectrometry (ESI-MS) and slope analysis showed that two TBP molecules involved in the extraction process of Li⁺, and the Li⁺ extraction mechanism obeyed the cation-exchange process. According to the red shift of the FT − IR peak of PO in TBP and the chemical shift changes of P in ³¹P NMR, the interaction strength between TBP and different metal ion followed the sequence: E_TBP−H >> E_TBP−Li > E_TBP−Mg > E_TBP−K > E_TBP−Na. It was also found that after a three−stage countercurrent extraction process, [Li⁺]_org was 0.42 g L⁻¹, and the total recovery efficiency of Li⁺ was about 98%. The saturated extraction capacity for Li⁺ could be as high as 5.4 g L⁻¹, and Li⁺ could be stripped with the aqueous solution containing 0.2 mol L^-1 HCl. In addition, the extraction efficiency of Li⁺ was almost not attenuated after 6 extraction cycles. This new extraction system shows a certain industrial application prospect for Li⁺ separation from the salt lake bine with high Mg/Li ratio.

针对含ILs和TBP的体系在离子液体（ILs）回收中存在的复杂问题，本工作提出了一种基于NaNTf ₂的协同萃取体系NaNTf ₂  + TBP，该体系无需降低锂分离能力。在最优提取参数下，Li ⁺的提取效率超过98%，而Mg ²⁺的提取效率仅为~1%。质谱（ESI-MS）和斜率分析结果表明，有两个TBP分子参与了Li + 的提取过程，Li ⁺的^提取机理服从阳离子交换过程。根据 P 的 FT - IR 峰的红移^{TBP中的O和31} P NMR中P的化学位移变化，TBP与不同金属离子的相互作用强度依次为：E _TBP-H  >>  E _TBP-Li  >  E _TBP-Mg  >  E _TBP-K  >  E _TBP-Na。还发现经过三级逆流萃取过程，[Li ⁺ ] _org为0.42 g L ^-1，Li ⁺的总回收率约为98%。^{Li +}的饱和萃取容量可高达 5.4 g L ^-1，而 Li ^{+可用含 0.2 mol L -1} HCl的水溶液汽提。此外，Li ⁺的萃取效率在 6 次萃取循环后几乎没有衰减。这种新的萃取系统在高镁锂比盐湖沼液中分离锂离子具有^一定的工业应用前景。