JEDDAH: Scientists at King Abdullah University of Science and Technology’s Center of Excellence for Renewable Energy and Storage Technologies have identified a key molecular barrier preventing aqueous rechargeable batteries from becoming a safer, cost-effective option for sustainable energy storage, the Saudi Press Agency reported on Saturday.
The findings, published in the peer-reviewed journal Science Advances, show how water shortens battery life and performance — and how adding low-cost salts such as zinc sulfate can counter this effect, extending battery life more than tenfold.
“A major factor in battery lifespan — aqueous or not — is the anode, where energy-generating chemical reactions occur. However, parasitic reactions at the anode degrade it over time,” the SPA reported. The study reveals that free water fuels these parasitic reactions, while zinc sulfate reduces free water levels, mitigating damage and improving performance.
Free water refers to water molecules not strongly bonded to others, making them more reactive. This state enables them to trigger unwanted reactions that consume energy and degrade the anode, according to the SPA.
“Our findings highlight the importance of water structure in battery chemistry — a key factor that has been largely overlooked,” said Husam Alshareef, KAUST professor, center chair, and the study’s principal investigator.
Sulfate was found to stabilize the bonds of free water, acting as what the KAUST team describes as “water glue,” altering water molecule dynamics to reduce parasitic reactions.
Most of the KAUST team’s experiments involved zinc sulfate-based batteries, but early results suggest sulfate has a similar stabilizing effect on other metal anodes. This points to a potentially universal solution for extending the lifespan of aqueous batteries.
“Sulfate salts are cheap, widely available, and chemically stable, making our solution both scientifically and economically viable,” said KAUST research scientist Yunpei Zhu, who led the experiments.
Aqueous batteries are attracting global attention as a sustainable solution for large-scale energy storage, with the market reportedly projected to surpass $10 billion by 2030.
Unlike the lithium batteries commonly used in electric vehicles, aqueous batteries “offer a safer, more sustainable option for integrating renewable energy sources like solar power into electrical grids — a key goal in Saudi Arabia’s energy transition,” according to the SPA’s report.
KAUST professors Omar Mohammed, Osman Bakr, Xixiang Zhang, and Mani Sarathy also contributed to the study.
