Ultrafast Ionic Cross‐Phase Transport in Nanofluidics for Simultaneously Boosting Osmotic Energy Conversion and Lithium Recovery

The implementation of an integrated system adept at simultaneously harvesting energy and recovering resources from currently abandoned environments represents an effective and strategic approach. Herein, we conceive a proof-of-concept ion-cross-phase system, capable of simultaneously harvesting osmotic energy and recovering lithium resources, a dual function not achieved by previous nanofluidics systems which normally focus on one aspect in aqueous environments. This process provides a synergistic driving force originating from ionic solvation energy during cross-phase transport and salinity gradient energy across concentration gradients, facilitating the transport of lithium ions from the organic phase to the aqueous phase. Molecular dynamics simulations validate that the enhanced lithium transport rate is activated by a reduction in the free energy, resulting from the coupling of cross-phase ionic solvation energy, and salinity gradient energy. Consequently, the system could harvest energy in treatment of organic industrial wastewater, which generates 7.2 kWh of electricity per day. Meanwhile, the lithium ions could be enriched in aqueous and converted into Li₂CO₃ products, with a purity greater than 99%. This work exemplifies a first strategic approach to the holistic recovery of sustainable energy and critical resources from organic-aqueous cross-phase industrial wastewater.