The King Abdullah University of Science and Technology’s (KAUST) Center of Excellence for Renewable Energy and Storage Technologies (CREST) has identified a key molecular factor limiting the wider adoption of aqueous rechargeable batteries, a safer and more cost-effective option for large-scale energy storage.

Published in Science Advances, the study reveals that free water molecules inside batteries can trigger unwanted chemical reactions, damaging internal components and reducing their lifespan.

The researchers found that adding zinc sulfate, an inexpensive and widely available salt, reduces these water molecules and extends the battery’s lifespan more than tenfold.

One of the most affected components is the anode, which is essential for storing and releasing energy. Excess free water reacts with the anode, causing energy loss. The researchers explained that zinc sulfate acts like “water glue,” binding the water molecules and preventing these harmful reactions.

“Our findings highlight the importance of water structure in battery chemistry, a key parameter that has been previously overlooked,” said Professor Husam Alshareef, Chair of CREST and principal investigator of the study.

While the research focused mainly on zinc-based batteries, early findings indicate that sulfate salts could have a similar stabilizing effect on other metal anodes. This suggests the potential for a universal approach to enhancing the durability of aqueous battery systems.

“Sulfate salts are cheap, widely available, and chemically stable, making our solution scientifically and economically viable,” added KAUST Research Scientist Yunpei Zhu, who led most of the experiments.

Aqueous batteries are gaining attention as a sustainable option for grid-scale energy storage, especially as countries work to integrate renewable sources such as solar power.

The global market for aqueous batteries is projected to exceed $10 billion by 2030, aligning closely with Saudi Arabia’s clean energy ambitions.