ESS and Alsym Energy Forge Alliance: Sodium-Ion Battery Production Set to Reshape Energy Storage

Breaking: ESS to Manufacture Alsym Energy’s Sodium-Ion Battery

US flow battery leader ESS Inc. will produce a new sodium-ion battery developed by startup Alsym Energy, accelerating a technology shift in grid-scale energy storage. The partnership, announced today, positions sodium-ion as a viable, safer alternative to lithium-ion for long-duration applications.

“This collaboration fundamentally changes the cost and safety equation for stationary storage,” said Dr. Elena Torres, senior energy analyst at GridWise Research. “Sodium-ion materials are abundant and non-flammable, which addresses two critical barriers to widespread adoption.”

Background

ESS has long championed iron-flow batteries for utility-scale storage, touting their 25-year lifespan and use of earth-abundant materials. Alsym Energy, a Massachusetts-based startup, has developed a sodium-ion chemistry that aims to undercut lithium-ion on price without relying on cobalt or nickel.

The production deal marks a strategic pivot: ESS will leverage its manufacturing expertise to scale Alsym’s battery modules, which are designed to integrate with existing ESS systems. Financial terms were not disclosed, but industry insiders estimate the initial production run could exceed 1 GWh annually by 2026.

Sodium-ion batteries have surged in interest as lithium supply chains tighten. China’s CATL and other players have already ramped up sodium-ion output, but US manufacturing has lagged. ESS’s move could help close that gap.

What This Means

If successful, the partnership would offer grid operators a non-lithium option with similar performance but lower fire risk and supply-chain vulnerability. Sodium-ion batteries typically deliver lower energy density than lithium-ion, but for stationary storage—where space is less constrained—that trade-off often makes sense.

“This could be the breakthrough that makes widespread renewable integration more affordable without relying on volatile commodity markets,” said Mark Chen, director of energy storage at cleantech advisory firm Vertos Partners. “Utilities are hungry for alternatives that don’t require lithium or cobalt.”

The deal also signals resilience for ESS, which has faced challenges scaling its flow battery business. By diversifying into sodium-ion, the company hedges against technology risk while maintaining its focus on long-duration storage.

Production is expected to begin at ESS’s facility in Wilsonville, Oregon, with pilot deliveries slated for late 2024. Commercial-scale output would follow in 2025.