ESS Tech / Alsym Energy partnership — 8.5 GWh of US-made non-lithium (sodium-ion) BESS cells and modules; ESS to integrate Alsym's sodium-ion chemistry into a broadened short/medium-duration storage platform alongside its iron-flow Energy Base; positioned for AI/data-center and grid-firming applications across the US

ESS Tech, Inc. (NYSE: GWH) signed a Letter of Intent with sodium-ion startup Alsym Energy to deploy 8.5 GWh of non-lithium BESS over the next several years — the largest non-lithium BESS partnership announced in the US to date. The deal pulls ESS into the short/medium-duration segment historically dominated by lithium-ion. ESS frames the move as creating a "unified non-lithium platform" spanning hours-long firming, daily energy shifting, and long-duration applications. Notable as a hedge against China-dominated lithium supply chains and a vote of confidence in sodium-ion commercialization.

Deal Details

Deal Type

Strategic Partnership / Supply LOI

Seller / Sponsor

ESS Tech, Inc. (Wilsonville, OR)

Buyer / Financier

Alsym Energy (Woburn, MA — sodium-ion cell developer)

Offtaker

Alsym Energy (Woburn, MA — sodium-ion cell developer)

Stage

Development

ISO/RTO

US

Source

BusinessWire / ESS Tech