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Salt lake brines have become the main source of lithium owing to their abundant reserves and low extraction costs. The low absolute concentration of Li+ and the complexity of accompanying ions in the brines are crucial issues, thereby inspiring the development of a variety of lithium extraction technologies. Among them, electrodialysis (ED) enables acceptable separation performance, reduced energy consumption, and near-zero pollution toward salt lake brines with a high Mg2+/Li+ mass ratio. Most recently, the rapid advancement of integrated ED technologies and emerging strategies for membrane material fabrications are conducive to facilitating the implementation of this technology. The newly proposed processes can achieve higher energy utilization and enhance the concentration of lithium salt products. For membrane materials, the superior permselectivity between lithium and magnesium is still the current pursuit. The key metrics for developing membranes involve tuning the materials’ hydrophilicity, pore size, and charge. Among them, due to the rise of lithium-specific recognition materials, it is believed that coupling them with ED technology to achieve efficient and precise extraction of lithium will be the future development direction.

Charge-governed ion transport is of significant importance to industrial development, and advanced membrane materials with fast and selective ionic transport are essential components. In cell membranes, ionic transport is mainly determined by the charge-governed protein channels, representing an architecture with functional differentiation. Inspired by this, a novel class of membranes was developed by ionically crosslinking sulfonated (poly[ether ether ketone]) and quaternized poly (2,6-dimethyl-1,4-phenylene oxide) to construct the cationic conductive biomimetic nanochannels. Ionic crosslinking was tailored to realize nanophase separation and efficient ion transport mainly based on surface chemistry without altering the scaffold feature of polymeric pore channels. The best-performing ionic crosslinking membrane exhibited a high ionic permeation (2.23 molÁm À2 Áh À1 for K + ) and high cationic selectivity (7.91 for K + /Mg 2+ ), which were comparable with the commercial monovalent cation permselective CIMS membrane, owing to the negligent surface resistance toward monovalent cations but strong positively charged repulsion against divalent cations.

In this study, a superhydrophobic composite hollow fiber membrane consisting of a fluorinated silicification layer (fSiO 2 ) upon a poly(vinylidene fluoride) (PVDF) substrate was developed via in situ silicification integrated with surface hydrophobic modification for bromine resources recovery from brine via membrane distillation (MD). The re-entrant hierarchical structure was established via surface silicification, after which (1H,1H,2H,2H-heptadecafluorodecyl) silane was introduced to transfer the surface property to be hydrophobic by reducing the surface energy with long fluorinated chains. The resultant fSiO 2 / PVDF composite membrane exhibited a superhydrophobic property with a water contact angle of 147°, which effectively prevents wetting when conducting MD, and performed a high permeating flux of 0.62 kg•m −2 •h −1 . In a long-term stability test of 10-day operation duration, the fSiO 2 /PVDF composite membrane remained decent, with flux declines of 1.8% and 38.3% when treated by the aqueous bromine solution and real brine, respectively. This work sheds insight into the fabrication of novel inorganic/organic composite membranes for bromine resource extraction from brine.