The larger the electrolyte supply tank, the more energy the flow battery can store. Flow batteries can serve as backup generators for the electric grid. Flow batteries are one of the key pillars of a decarbonization strategy to store energy from renewable energy resources.
China and Russia dominate the market for vanadium, the metal that makes flow batteries durable and easy to maintain. “The supply chain for vanadium is extremely precarious,” said Kara Rodby, a battery analyst at the investment firm Volta Energy Technologies. Still, flow batteries are making their debut in big real-world projects.
“It looks like flow batteries are finally about to take off with interest from China,” said Michael Taylor, an energy analyst at the International Renewable Energy Agency, an international group that studies and promotes green energy.
A new iron-based aqueous flow battery shows promise for grid energy storage applications. A commonplace chemical used in water treatment facilities has been repurposed for large-scale energy storage in a new battery design by researchers at the Department of Energy's Pacific Northwest National Laboratory.
A model of the flow battery system run by the Hokkaido Electric Power Network. But experts say there might be better options. Lithium-ion batteries are perfect for smartphones because they’re lightweight and fit in small spaces, even if they don’t last long and have to be replaced frequently.
Iron-based flow batteries designed for large-scale energy storage have been around since the 1980s, and some are now commercially available. What makes this battery different is that it stores energy in a unique liquid chemical formula that combines charged iron with a neutral-pH phosphate-based liquid electrolyte, or energy carrier.