Researchers in engineering at the University of Alberta have developed a method that significantly improves the performance of water-based rechargeable batteries, positioning them as a safer and more affordable alternative to traditional lithium-ion batteries.

Water-based batteries (aqueous batteries) have existed since the 19th century, with the lead-acid battery invented in 1859 being a famous example still widely used to start internal combustion engine vehicles today. However, water-based batteries have long suffered from serious limitations, such as low energy density, limited voltage, and insufficient storage capacity, making them unsuitable for powering electric vehicles or reliably storing renewable energy such as solar or wind power.

In contrast, lithium-ion batteries offer advantages including high energy density, fast charging, long lifespan, and light weight, but they also come with significant risks of fire or explosion and high costs.

Now, materials scientists Wang Xiaolei and PhD student Xu Zhixiao from the Department of Chemical and Materials Engineering at the University of Alberta announced a breakthrough that narrows the performance gap between water-based batteries and lithium-ion batteries. Their research details a redesigned electrode structure that improves key performance metrics of water-based batteries, including energy density, charging speed, and lifespan.

Wang Xiaolei explained that water-based batteries are cheaper because they use only water, making them easy to handle, non-toxic, and non-flammable. However, performance has always been their challenge. Organic material batteries like aqueous batteries typically have poor conductivity. Adding extra carbon can compensate for this, but it reduces the space for actual energy storage materials, further limiting energy capacity.

The Wang Xiaolei team solved this problem by redesigning the battery electrodes (the components that store energy). Unlike lithium-ion batteries that rely on organic solvents, water-based batteries use water-based electrolytes to transport current between the cathode and anode. The team's developed pressurized organic electrodes have made significant progress, enhancing chemical reactivity, electrical conductivity, thermal stability, mechanical strength, and adhesion properties. Wang Xiaolei stated that this enables the battery to charge faster, last longer, and store more energy, with performance nearly surpassing all other organic batteries.

Currently, the team has demonstrated the technology using coin-sized batteries and larger prototypes about the size of a small sandwich bag. Although the laboratory results are encouraging, Wang Xiaolei acknowledged that scaling up to larger battery sizes remains a key challenge.

In the next phase, the team will seek industry partners to help expand the technology for practical applications. Wang Xiaolei said the goal is to manufacture batteries for large-scale (industrial) energy storage. If it can achieve performance comparable to electric vehicle batteries at lower cost and with lower safety risks, that would also be a good outcome.

Currently, the university team is seeking commercial partners to bring the pressurized organic electrode design to market, marking a potential step forward in the search for safer and more scalable energy storage solutions.