An efficient lithium extraction pathway in covalent organic framework membranes

Lithium extraction is one of the most important techniques in the energy-storage field, which plays a crucial role for the sustainable development of lithium batteries. In Matter, Ma, Sun, and colleagues developed a COF-based membrane implanted with oligoether side chains to provide a selective lithium ion-diffusion pathway. Thanks to the precise control over the structure and surface chemistry of the nanopores in COF, the oligoether-functionalized COF membrane allows efficient transport of Li⁺ whereas obstructs the passing through of other ions, leading to an improved Li⁺/Mg²⁺ separation factor up to 64. This work highlights the significance of pore-environment engineering for developing customized membrane materials for ion sieving and lithium ion extraction.