Selective membrane for Li recovery from Na-rich solutions

CMI Highlight: Selective membrane for Li recovery from Na-rich solutions

Illustration of a single-stage electrodialysis cell.
illustration of a single-stage electrodialysis cell.

CMI researchers at University of South Florida and Idaho National Laboratory conducted the research for this highlight

Li+/Na+, Li+/K+, and Li+/Mg2+ selectivity and recovery using the functionalized membrane at room and elevated temperature.
Li+/Na+, Li+/K+, and Li+/Mg2+ selectivity and recovery using the functionalized membrane at room and elevated temperature.

Innovation 
Novel graphene–polysulfone membranes optimized with crown-ether nanochannels selectively trap Na⁺ while allowing Li⁺ to permeate. 

Achievements
The new membrane has been integrated with electrodialysis to outperform commercial membranes and deliver unprecedented Li⁺/Na⁺ selectivity:

  • >2× higher selectivity at 25 °C compared with commercial membranes
  • >11× higher selectivity at 60 °C
  • DOI: 10.1016/j.seppur.2026.138352

Significance and Impact

  • Sustainable path to critical mineral recovery
  • Enables Li recovery from complex feedstocks
  • Scalable membrane fabrication using cheap graphite

Hub Target Addressed 
Highly selective extraction and separation
 

Li⁺ purity, Li+/Na+ selectivity, and recover yield across three sequential electrodialysis stages at elevated temperature.
Li⁺ purity, Li+/Na+ selectivity, and recover yield across three sequential electrodialysis stages at elevated temperature.