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RedoxBlox raising funds for thermochemical battery

Jan 16, 2024
Illustration of a cube with a glowing power bolt.

Illustration: Gabriella Turrisi/Axios

Energy storage startup RedoxBlox is in the process of raising the second tranche of its Series A round of at least $13 million to build larger versions of its modules.

Why it matters: The company is targeting two huge sectors with large greenhouse gas footprints: industrial heat and natural gas power.

Catch up quick: The San Diego-based company announced last week that it had raised $25 million in funds in a combination of grants from the Department of Energy and the California Energy Commission, and the first tranche of its Series A round, led by Khosla Ventures.

  • Breakthrough Energy Ventures and Red Cedar Ventures also participated in the first part of the Series A.
  • BEV led the startup's seed round, and ARPA-E funded two of its projects.

How it works: RedoxBlox, which was spun out of Michigan State University in 2021, has developed metal oxide pellets made up of low cost Earth-abundant materials.

  • When electricity flows through the material and heats it up, a chemical reaction releases oxygen and stores heat in the form of chemical energy.
  • The company says its modules have energy density comparable to lithium-ion batteries but for a much lower cost.
  • Its goal is to provide long-duration grid-scale storage at a levelized cost of energy storage at less than 5 cents per kilowatt hour electrical, said James Klausner, co-founder and executive chairman.

Zoom in: RedoxBlox is looking to sell the modules to both power companies as a drop-in replacement for natural gas combustors and companies that use industrial heat, such as cement, aluminum and steel makers.

  • "We have half a dozen customers who said when we have a product, they'll buy it," said RedoxBlox Vice President of Business Development Scott McNally.
  • RedoxBlox has operated a 100 kWh prototype reactor in a lab and is in the process of building a 2 MWh system, followed by two 10 MWh projects.

Big picture: In recent years an increasing number of startups focused on novel forms of energy storage have emerged including those making thermal batteries like Fourth Power, Antora Energy, and Rondo Energy.

  • The Inflation Reduction Act has unlocked tax credits for thermal storage.
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