Development of technology for recovering lithium from seawater by electrodialysis using ionic liquid membrane

•I propose a new method for Li recovery from seawater by electrodialysis using an ionic liquid.•The divalent ions were removed for producing concentrated seawater.•Almost all Li ions remain on the anode side, whereas the other ions in the concentrated seawater permeate to the cathode side through the ionic liquid with an applied electric voltage of 2–3 V.•The Li survival ratio remained high and was 63% after electrodialysis.

Tritium fuel for fusion reactors is produced by reacting lithium-6 (6Li) with neutrons in tritium breeders. This study demonstrates a method for Li recovery from seawater, wherein Li does not permeate from the anode side to the cathode side through an ionic liquid N,N,N-trimethyl-N-propylammonium–bis(trifluoromethanesulfonyl) imide. Almost all Li ions remain on the anode side (seawater), whereas the other ions in the seawater permeate to the cathode side through the ionic liquid with an applied electric voltage of 2–3 V.