Scientists left water inside a battery and nearly doubled its power

Scientists have discovered that leaving natural water content in a sodium-based battery material significantly enhances its performance, potentially offering a more sustainable energy storage solution. Sodium is a common and widely available element found in seawater, salt deposits, and many minerals, making it an attractive candidate for lower-cost energy storage compared to lithium-ion batteries.

Sodium ion batteries operate similarly to lithium-ion batteries, with charged sodium particles moving between two electrodes during charging and discharging. However, many sodium ion materials have struggled to match the performance of lithium-ion technology in terms of charge storage, charging speed, and longevity. In a study published in the Journal of Materials Chemistry A, researchers at the University of Surrey found that keeping the water content in a specific sodium vanadium oxide material, known as nanostructured sodium vanadate hydrate, led to dramatic improvements.

This hydrated material stored almost twice as much charge as typical sodium-ion materials and charged much faster while remaining reliable for over 400 charge cycles. The water-containing version also demonstrated electrochemical desalination capabilities, effectively removing dissolved salt from the surrounding water. This dual functionality—energy storage and water treatment—could have significant implications for coastal regions with limited access to fresh water but abundant seawater and renewable energy resources.

The researchers noted that this discovery could potentially lead to future devices that combine energy storage with water treatment, using seawater as a safe, free, and abundant electrolyte while simultaneously producing fresh water. However, further testing is needed before this approach can be applied to commercial batteries or large-scale desalination systems.