Australian scientists have developed a groundbreaking water-based redox flow battery that could drastically change how we store rooftop solar energy.
Redox Flow Battery Could Change How We Store Solar Energy
The world needs clean energy, and that means finding better ways to store it. Solar and wind power are great, but the sun doesn’t always shine, and the wind doesn’t always blow. That’s where energy storage comes in. One promising technology is the redox flow battery (RFB), which is like a rechargeable battery on a much larger scale.
Scientists at Monash University in Australia have created a water-based “flow battery” that promises to make storing rooftop solar energy easier, safer, and cheaper for household use. This new type of battery could outperform the current expensive lithium-ion batteries, which can cost about $10,000. Unlike traditional flow batteries that are large and slow to charge, this new design uses a special membrane that lets it charge quickly and work efficiently in homes.
Why is This Battery Better?
The key improvement lies in the membrane, which controls how ions—tiny charged particles—move inside the battery. The team designed a membrane that lets good ions pass quickly while blocking others that could slow down or damage the battery. This results in faster charging times and longer-lasting performance. In fact, tests showed it could handle more than 600 high-current charging cycles with almost no loss of capacity.
Why Redox Flow Batteries?
RFBs offer several key advantages. First, they’re scalable, meaning you can build them to store enormous amounts of energy. Second, they tend to have a long lifespan compared to other batteries. Third, they’re safer because they typically use non-flammable electrolytes, reducing fire risks. However, traditional vanadium RFBs are expensive. This is where innovative research steps in.
The Rise of Organic Redox Flow Batteries (ORFBs)
Organic redox flow batteries (ORFBs) are emerging as a more cost-effective and environmentally friendly alternative. They use organic compounds instead of expensive metals like vanadium. One example uses 2,6-dihydroxyanthraquinone (2,6-DHAQ) and potassium ferrocyanide (K4Fe(CN)6) – readily available and relatively cheap materials. This makes them a much more appealing option for large-scale energy storage.
Nevertheless, ORFBs face their own set of hurdles. One major issue is electrolyte crossover, where the different chemicals mix, shortening the battery’s life. Current membranes, such as Nafion, are both expensive and potentially environmentally harmful. Consequently, researchers are developing better membranes to solve this problem. This is where new materials science comes into play.
Superior Performance
The Monash team’s flow battery boasts exceptional performance. In testing, it outperformed the industry-standard Nafion membrane in both speed and stability, completing 600 high-current cycles with minimal capacity loss. This is a significant leap forward for this type of battery technology. The researchers successfully achieved a crucial balance between safety, affordability, and speed—a feat rarely seen in other existing systems.
A Breakthrough in Membrane Technology
Recently, scientists have made a significant breakthrough by developing a new type of membrane using a sulphonated hyper-crosslinked polymer. This innovative membrane allows for faster transport of certain ions while effectively blocking the crossover of the active redox molecules. This significantly improves the battery’s performance and lifespan. Importantly, this new membrane is also much cheaper and easier to produce than existing options. This development has the potential to accelerate the adoption of ORFBs for large-scale energy storage, paving the way for a cleaner energy future.
Key Benefits of SPEEK-SX2 Membranes
- Selective Ion Transport: The membrane lets sodium ions pass quickly while blocking larger redox molecules like 2,6-DHAQ and Fe(CN)64−, stopping them from crossing over.
- High Stability: It supports battery cycles at high current densities (up to 160 mA/cm2) for hundreds of charges and discharges without degrading performance.
- Cost-Effective & Scalable: Made from abundant materials with an easy manufacturing process suitable for large-scale production.
The Future is Bright
This research highlights the incredible potential of ORFBs. This breakthrough is part of larger efforts to support renewable energy worldwide. Flow batteries like this one can help more people store solar energy efficiently and reduce dependence on fossil fuels. Projects at Monash University already use big flow battery systems to help power their campus sustainably, with goals set toward net zero emissions by 2030.
Reference
- Liang, W., Ghasemiestahbanati, E., Eden, N. T., Acharya, D., Doherty, C. M., Majumder, M., & Hill, M. R. (2025). Flow Battery with Remarkably Stable Performance at High Current Density: Development of A Nonfluorinated Separator with Concurrent Rejection and Conductivity. Angewandte Chemie International Edition, 64(25). https://doi.org/10.1002/anie.202505383
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Neha Adikane holds a Master’s degree in Environmental Science from Pune University, bringing a unique blend of scientific expertise and creative writing skills to her craft. She specializes in creating engaging, insightful, and impactful content across various niches. With a passion for translating complex ideas into simple, relatable narratives, she excels at crafting blogs, articles, website content, and social media posts that captivate readers and drive engagement. Neha’s background in environmental science adds depth to her writing, allowing her to effectively cover topics related to sustainability, eco-awareness, and scientific innovations.