# Thomas Sisto

> 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.

- **Role:** CEO & Co-Founder at XL Batteries
- **Organizations:** XL Batteries, Columbia University, University of Oregon
- **Nationality:** American
- **Education:** B.A. in Chemistry, Colby College, M.S. in Organic Chemistry, Boston University, Ph.D. in Organic Chemistry, University of Oregon, Postdoctoral Fellowship, Organic Chemistry & Device Fabrication, Columbia University
- **Known for:** Co-founded and leads XL Batteries, which has raised over $20 million for non-lithium long-duration energy storage, Discovered an organic molecule that set a record for accepting the highest number of electrons into a single molecule, Translated a Columbia lab discovery into a working grid-scale battery architecture using pH-neutral saltwater

## Career timeline

- **2009-2010** — Taught chemistry at Fryeburg Academy, where he established an organic chemistry course for seniors
- **2010-2015** — Graduate student / Ph.D. researcher in organic chemistry at the University of Oregon
- **2015-2019** — Postdoctoral research fellow at Columbia University in the Nuckolls group, developing organic molecules for solar cells
- **2019** — Co-founded XL Batteries, spinning the technology out of Columbia, and became CEO
- **2025** — Commissioned XL Batteries' first commercial pilot with Stolthaven Terminals in Houston and partnered with Prometheus Hyperscale for data-center storage

## Achievements

- Co-founded and leads XL Batteries, which has raised over $20 million for non-lithium long-duration energy storage
- Discovered an organic molecule that set a record for accepting the highest number of electrons into a single molecule
- Translated a Columbia lab discovery into a working grid-scale battery architecture using pH-neutral saltwater
- Shipped XL Batteries' first commercial unit and launched a pilot with petrochemical-storage firm Stolthaven Terminals
- Secured a partnership with Prometheus Hyperscale to deploy long-duration storage at data centers

## Latest updates

- **2025-04** — XL Batteries commissioned its first grid-scale organic flow battery pilot with Stolthaven Terminals in Houston.
- **2025-05** — XL Batteries was tapped to provide long-duration onsite energy storage for data-center developer Prometheus Hyperscale.
- **2025-07** — Sisto publicly discussed lithium-ion supply-chain risks and a domestic path to energy resilience.

## Links

- Website: https://xlbatteries.com
- LinkedIn: http://www.linkedin.com/in/thomas-sisto-07330a172
- Twitter/X: https://twitter.com/tjsisto
- YouTube: https://www.youtube.com/watch?v=l4QJjTW-lGU

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Profile page: https://yespress.io/thomas-sisto
Published by YesPress — https://yespress.io
Last updated: 2026-06-21