
Australian researchers have unveiled a new water-based “flow battery” that could revolutionize how households store rooftop solar power—at a fraction of today’s costs. Developed at Monash University, the system uses a redesigned membrane that makes flow batteries, once considered too bulky and slow for home use, fast and compact enough to compete with lithium-ion technology. Unlike lithium systems, which can cost up to $10,000, the new liquid battery is inexpensive, non-toxic, and non-flammable—making it safer and more accessible for everyday households.

The breakthrough lies in the team’s custom membrane, which improves ion selectivity and allows stable, high-speed operation across hundreds of charge cycles. In tests, the Monash design outperformed the industry-standard Nafion membrane, maintaining capacity through 600 high-current cycles. Researchers are now 3D-printing prototypes for real-world trials, with commercial availability expected within a few years. By combining affordability, safety, and long-term stability, this innovation could accelerate solar adoption in homes and push Australia—and the world—closer to a cleaner, more energy-independent future.

Source: 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.

Non-toxic, affordable, and fast: this new liquid solar battery could solve the worst problems with renewable energy.