DeepTech Talk: The Future of Aqueous Zinc Flow Batteries

Chris

Welcome back to DeepTech Talk, the podcast where we unpack the technologies reshaping the industrial and energy future. I’m Chris, and today, we’re diving into one of the most promising contenders in the grid-scale storage space: aqueous zinc flow batteries. If you’re following energy storage trends, you know lithium-ion dominates the market, but it also comes with baggage—fire risks, resource constraints, and supply chain headaches. Sarah, what do you think about the current state of energy storage?

Sarah

Hi, Chris! It’s great to be here. I think the current state of energy storage is fascinating, but it’s also a bit daunting. Lithium-ion batteries are everywhere, but the issues you mentioned are real. I’ve heard that aqueous zinc flow batteries are offering a safer and more sustainable alternative. Can you tell us more about why they are so promising?

Chris

Absolutely, Sarah. Aqueous zinc flow batteries are a game-changer because they address many of the shortcomings of lithium-ion. According to a report from BIS Research, the market for these batteries is projected to grow from $259.6 million in 2024 to $2.16 billion by 2034, with a compound annual growth rate of 23.6%. This isn’t just a marginal improvement; it’s a significant shift toward large-scale, stationary storage systems that are safer, more cost-effective, and better suited for long-duration storage. What do you think is driving this growth?

Sarah

Hmm, that’s a huge market potential. I think the driving factors could be the safety and sustainability of these batteries. For instance, they are non-flammable, which makes them ideal for densely populated areas or near critical infrastructure. Plus, the materials used—primarily zinc and water-based electrolytes—are abundant, non-toxic, and inexpensive compared to lithium or vanadium. Do you have any specific examples of how this safety aspect is being leveraged?

Chris

Great points, Sarah. One example is the 20 MWh aqueous zinc battery project in California. It’s now seen as a benchmark for replacing diesel peaker plants. This project provides multi-hour discharge capability, ideal for smoothing solar and wind intermittency. In Asia, utility companies in South Korea and Japan are also piloting zinc flow batteries for backup storage at data centers and industrial parks, particularly where fire risk is a concern. These applications highlight the real-world benefits of these batteries. What other aspects of safety and sustainability do you think are important to consider?

Sarah

Hmm, I think the modular and scalable design is another crucial aspect. The ability to adjust power and energy ratings independently makes these batteries suitable for everything from microgrids to utility-scale installations. This flexibility is a significant advantage. Can you explain how this modular design works in more detail?

Chris

Certainly, Sarah. Unlike conventional batteries where energy is stored in solid electrodes, flow batteries store energy in liquid electrolytes housed in external tanks. In zinc flow systems, one side typically uses a zinc electrode, and the other side can vary—some use bromine, others nickel or air-based cathodes. The aqueous setup uses water-based electrolytes, which are inherently safer and enable operation under a wider range of temperatures. The result? High cycle life, minimal degradation, and enhanced safety. This makes them perfect for long-duration storage needs in renewables-heavy grids. Any thoughts on the real-world applications of this technology?

Sarah

Umm, I’m curious about the commercial traction. You mentioned Zinc8 Energy Solutions, which completed testing of a zinc-nickel flow battery that increased energy density by nearly 40%. That’s a major breakthrough. Are there other companies making significant strides in this space?

Chris

Absolutely, Sarah. Key players in this space include Zinc8 Energy Solutions, Primus Power, and ViZn Energy. Eos Energy is also a notable player, though they focus on zinc hybrid cathodes. Startups and legacy players alike are investing in new chemistries and manufacturing models. One big focus right now is simplifying system architecture to reduce costs and improve round-trip efficiency, which currently sits around 70–80%. The policy environment is also shifting in zinc’s favor, with grid operators and regulators pushing for non-lithium storage alternatives. How do you see policy and regulatory support impacting the growth of these batteries?

Sarah

I think policy and regulatory support are crucial. The U.S. Department of Energy has named zinc-based chemistries as a ‘priority pathway’ for long-duration storage under its Energy Earthshots Initiative. This kind of support can really accelerate the adoption of these technologies. What do you think are the biggest hurdles in scaling up the manufacturing of these batteries?

Chris

The biggest hurdle is indeed manufacturing scale. But if companies can bring down the cost per kilowatt-hour to competitive levels—say under $200 for long-duration systems—zinc flow could carve out a significant share of the storage market, especially in applications where lithium just doesn’t fit the risk profile. Innovations in manufacturing processes and materials are key to achieving this. Any final thoughts on the future of aqueous zinc flow batteries, Sarah?

Sarah

I think the future looks very promising. With strong policy support, rising interest from utilities, and ongoing innovations, aqueous zinc flow batteries are stepping into the commercial mainstream. They offer a compelling trifecta—safety, scalability, and sustainability. It’s exciting to see how these technologies will continue to evolve and reshape the energy storage landscape. Thanks, Chris, for this insightful discussion!

Chris

Thank you, Sarah. That’s it for today’s episode of DeepTech Talk. For more insights, check out the full BIS Research report on the aqueous zinc flow battery market. I’m Chris—thanks for tuning in, and we’ll catch you next time with more on the deep tech powering our future.