Ion Tide
A surprisingly simple change to sodium-ion battery electrodes opens the door to simultaneous energy storage and seawater desalination. Na⁺ ions intercalate into the crystal lattice during each charge cycle — pulling them out of seawater and leaving fresh water behind, one tide at a time. August 2026.
voltage3 V
sea Na⁺ 28fresh Na⁺ 4🔋 0%
Seawater salinity
~35 g/L NaCl
Drinking water
<0.5 g/L Na⁺
Battery type
Sodium-ion (Na-ion)
Mechanism
Ion intercalation
vs Li-ion cost
Lower — Na abundant
Energy recovery
~60–80% round-trip
Electrode material
Prussian blue analogue
Key insight
Dual-use single cycle
Dual-use cycle · Na-ion battery + desalination