Improving the Performance of Rechargeable Aqueous Batteries

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Researchers at the University of Alberta have developed a new method to significantly improve the performance of environmentally friendly, water-based rechargeable batteries.

These “aqueous” batteries use a water-based electrolyte, offering a safer and potentially cheaper alternative to conventional lithium-ion batteries. However, they have long suffered from limitations such as low energy density and limited storage capacity.

The research is published in Nature Communications.

Pressurized electrodes lead to performance gains

Led by Xiaolei Wang, a professor of chemical and materials engineering, and graduate researcher Zhixiao Xu, the research team focused on improving the electrochemical performance of these water-based batteries by redesigning the electrode materials.

Aqueous batteries have been used since the 19th century, with the lead-acid battery being a well-known example. Despite their long history and safe profile, their inability to match the power and longevity of lithium-ion systems has limited their application in areas like electric vehicles and large-scale renewable energy storage.

The new innovation enhances aqueous batteries in multiple performance metrics, including energy density, charge capacity and thermal stability. By optimizing the composition and structure of the electrodes, the researchers improved the chemical reactivity and electrical conductivity of the battery, while maintaining mechanical strength and adhesion.

Unlike lithium-ion batteries, which use organic solvents as electrolytes, aqueous batteries rely on water-based electrolytes. While safer, these batteries typically struggle with conductivity and energy storage due to the poor electrical performance of organic electrode materials. To address this, the Alberta team introduced structural changes that allow the battery to store and release energy more efficiently.

Lab-scale success with potential for industrial application

The team tested their innovation using small-scale prototypes, including coin-sized batteries and a larger cell comparable in size to a sandwich bag. These models showed improved performance, including faster charging, higher energy retention and extended operational life compared to other organic battery designs.

While these findings represent a meaningful advance in battery technology, further development is required to scale the system for industrial or vehicular applications. 

The research team’s goal is to enable the use of this safer, more sustainable battery technology for broader applications, including grid-scale energy storage systems. The researchers note that achieving cost parity and safety improvements over existing lithium-ion systems could make aqueous batteries a viable option for more widespread use.

Reference: Xu Z, Xu Y, Qiu Y, et al. Pressurized organic electrodes enable practical and extreme batteries. Nat Commun. 2025;16(1):4561. doi: 10.1038/s41467-025-59892-y