Preliminary studies of lithium recovery technology from seawater by electrodialysis using ionic liquid membrane

Lithium (Li) procurement is becoming a matter of importance worldwide. I propose a new method for recovering Li from seawater by electrodialysis, wherein Li selectively permeates from the anode side to the cathode side through an organic membrane impregnated with an ionic liquid (PP13-TFSI). Measurements of the ion concentration at the cathode side as a function of dialysis duration showed that the Li concentration increased to 5.94% after 2 h with an applied electric voltage of 2 V. Moreover, the other ions in the seawater did not permeate the membrane. With both ends of the impregnated membrane covered with a Nafion 324 overcoat to prevent outflow of the ionic liquid, the Li concentration increased to 22.2%. This new recovery method shows good energy efficiency and is easily scalable and thus is suitable for use in seawater desalination plants.