LAUSR

This study proposes a novel strategy for enhancing Li+ extraction from brines by π‐electron donor‐based ionic liquid (IL) extractant systems. The binary extractant system of [A2MIM][Tf2N] and tri‐isobutyl phosphate was experimentally selected, with a single‐stage extraction efficiency of up to 95.87% and separation selectivity of Li+/Mg2+ of 817.15, respectively. The molecular‐level mechanism for Li+ extraction was unraveled by quantum chemical calculations and molecular dynamics simulations. It is found that enhancing Li+ extraction with the π‐electron donor‐based IL serves two main aspects of increasing the hydrogen bond interaction of the IL–cation and H2O resulting in Li+ hydration (Li+···O‐H) disruption and improve Li+ transfer into the organic phase by more competitive coordination of Li+‐[Tf2N]− (Li+···O=S), namely, the so‐called “Li+ hydration disruption‐phase transfer enhancement induced by π‐electron donor‐based ILs” effect. This work provides a theoretical guidance for developing high‐efficiency IL‐based extractants for Li+ extraction.