Enabling an ultraefficient lithium-selective construction through electric field–assisted ion control
- Yan Zhao
- Xue Yan
- Lei Xia
- Yangbo Qiu
- Shuang Zheng
- Gang Lu
- Yaoming Wang
- Yang Zhang
- Jiangnan Shen
- Xi Zhang
- Xing Yang
- Jefferson Zhe Liu
- Raf Dewil
- Congjie Gao
- Bart Van der Bruggen
2025-07-16
Membranes with precise ion transport behaviors are regarded as an alternative for lithium (Li) extraction from water streams. Current membranes demonstrate limited viability due to the lack of efficient Li + -selective architectures. We propose an electric field–assisted ion control hypothesis in reinforcing ultraefficient Li + -selective membranes, in which an ionized zeolitic imidazolate framework layer (Q-PEI@ZIF) is constructed via polyethylenimine (PEI) in situ confinement conversion and subsequent quaternization of 2,3-epoxypropyl trimethyl ammonium chloride. In electrodialysis at 5 milliampere per square centimeter, the resulting membrane Q(5%)-PEI(1.0)@ZIF#CEM shows that the ion permeation rates follow the order of K + ~ Li + > Na + > Ca 2+ ~ Mg 2+ , corresponding to 0.31, 0.30, 0.25, 0, and 0 mole per square meter per hour in 120 minutes, respectively. With a 25-millimolar Li + /Mg 2+ mixed solution, it exhibits an unprecedented Li + /Mg 2+ permselectivity of 20,000 and 99.99% purity of Li + product in 120 minutes. This study expands the hypothesis of electric field–assisted ion control in enabling an ultraefficient Li + -selective construction.