The researchers described seawater storage systems as a derivative of rechargeable sodium-ion batteries (NIB), which offer a series of advantages in terms of raw material costs and safety. However, they also have limited ability to hold a charge after repeated cycles of charging and discharging.

“In addition, using other ion-selective membranes would enable elemental harvesting within the context of lithium extraction,” they said. “Alternatively, nonselective membranes would boost the performance in seawater because cations beyond sodium would be removed.”

They said seawater batteries could easily replace some seawater reverse-osmosis components and might also be useful to extract sodium ions from seawater.