Polystyrene Sulfonate Threaded through a Metal–Organic Framework Membrane for Fast and Selective Lithium‐Ion Separation |
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| Authors: | Dr Yi Guo Dr Yulong Ying Dr Yiyin Mao Prof Xinsheng Peng Prof Banglin Chen |
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| Institution: | 1. State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China;2. Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX, USA |
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| Abstract: | Extraction of lithium ions from salt‐lake brines is very important to produce lithium compounds. Herein, we report a new approach to construct polystyrene sulfonate (PSS) threaded HKUST‐1 metal–organic framework (MOF) membranes through an in situ confinement conversion process. The resulting membrane PSS@HKUST‐1‐6.7, with unique anchored three‐dimensional sulfonate networks, shows a very high Li+ conductivity of 5.53×10?4 S cm?1 at 25 °C, 1.89×10?3 S cm?1 at 70 °C, and Li+ flux of 6.75 mol m?2 h?1, which are five orders higher than that of the pristine HKUST‐1 membrane. Attributed to the different size sieving effects and the affinity differences of the Li+, Na+, K+, and Mg2+ ions to the sulfonate groups, the PSS@HKUST‐1‐6.7 membrane exhibits ideal selectivities of 78, 99, and 10296 for Li+/Na+, Li+/K+, Li+/Mg2+ and real binary ion selectivities of 35, 67, and 1815, respectively, the highest ever reported among ionic conductors and Li+ extraction membranes. |
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| Keywords: | lithium-ion separation membranes metal– organic framework membranes sulfonate networks transport properties |
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