Highly efficient separation of lithium isotopes using an EMC-based electromigration system

Efficient separation of lithium isotopes is crucial for nuclear energy, isotope geochemistry, and advanced energy storage. This study developed an electromigration system that uses organic solvents as the separation medium. The system investigated the effects of solvent type, lithium salt species, and migration path length. The EMC-based system demonstrated superior isotopic selectivity, achieving a separation factor exceeding the industrial benchmark of 1.050 under conditions of 16 V, 0.1 mol∙L −1 LiTFSI anolyte, a 10 cm path length, and 3 h of operation. In contrast, the DMA-based system exhibited significantly higher Li + flux due to weaker coordination, albeit with lower isotope selectivity. Molecular dynamics simulations revealed distinct solvation behaviors. EMC formed dense LiTFSI clusters that enhanced isotope selectivity but impeded ion transport, whereas DMA formed looser complexes that facilitated faster ion migration. Radial distribution functions and coordination numbers confirmed stronger Li + interactions with EMC compared to DMA. These findings establish a mechanistic understanding of the trade-off between isotopic separation efficiency and ion flux, providing both theoretical and experimental guidance for designing high-performance lithium isotope separation systems.