Fluorine-Rich Supramolecular Nano-Container Crosslinked Hydrogel for Lithium Extraction with Super-High Capacity and Extreme Selectivity

Extraction and recovery of lithium from reserves play a critical role in the sustainable development of energy due to the explosive growth of the lithium-battery market. However, the low efficiency of extraction and recovery seriously threatens the sustainability of lithium supply. In this contribution, we fabricate a novel mechanically robust fluorine-rich hydrogel, showing highly efficient Li⁺ extraction from Li-containing solutions. The hydrogel was facilely fabricated by simple one-pot polymerization of supramolecular nanosheets of fluorinated monomers, acrylic acid and a small amount of chemical crosslinkers. The hydrogel exhibits a remarkable lithium adsorption capacity (Q_m Li⁺=122.3 mg g⁻¹) and can be reused. Moreover, it can exclusively extract lithium ions from multiple co-existing metal ions. Notably, the separation of Li⁺/Na⁺ in actual wastewater is achieved with a surprising separation factor of 153.72. The detailed characterizations as well as calculation showed that the specific coordination of Li−F plays a central role for both of the striking recovery capability and selectivity for Li⁺. Furthermore, an artificial device was constructed, displaying high efficiency of extracting lithium in various complex actual lithium-containing wastewater. This work provides a new and promising avenue for the efficient extraction and recovery of lithium resource from complex lithium-containing solutions.