XL Batteries is a Marlborough, Massachusetts startup building an Organic Flow Battery for grid-scale, long-duration energy storage. Spun out of Columbia University chemistry research, the company uses proprietary organic molecules dissolved in pH-neutral water instead of vanadium in acid - producing a non-flammable, non-toxic, non-corrosive battery assembled from commodity pumps, tanks and tubes. The pitch: safe, scalable storage that can run for 10, 20, even 50 hours by simply enlarging the tanks, at costs targeted below lithium-ion for long durations.
Thomas Sisto is the CEO and co-founder of XL Batteries, a Marlborough, Massachusetts startup commercializing water-based organic flow batteries for long-duration, grid-scale energy storage. A synthetic organic chemist by training, Sisto discovered the company's core molecule during a Columbia University postdoc - a compound he originally designed for solar cells that turned out to be extraordinarily stable in pH-neutral saltwater. He spun XL out of Columbia in 2019 and has since steered it from a lab curiosity to its first commercial pilot, betting that cheap, abundant organic chemicals can break China's grip on the battery supply chain.