Keeping Water Inside Sodium-Vanadium Oxide Doubles Battery Power and Enables Desalination

University of Surrey researchers found that preserving the natural water in sodium vanadium oxide almost doubles sodium-ion battery capacity and enables seawater desalination.

Scientists at the University of Surrey investigated nanostructured sodium vanadate hydrate, a sodium-vanadium oxide that naturally incorporates water molecules. By retaining this water rather than heat-treating the compound, they achieved roughly double the charge capacity of conventional sodium-ion cathodes, rapid charging and reliable performance for more than 400 cycles. When tested in salt water, the hydrated cathode continued to operate and simultaneously removed dissolved sodium, while a graphite electrode captured chloride, illustrating an electrochemical desalination process.

Lead researcher Daniel Commandeur noted that the discovery challenges the long-standing belief that moisture harms battery components. The breakthrough points to sodium-ion batteries as a lower-cost alternative to lithium-ion technology that could also produce fresh water, especially in coastal areas. Commercial application will require further development and scaling.