Alsym Na-Series Non-Flammable Sodium-Ion Batteries

Alsym Energy is an American battery technology company based in Malden, Massachusetts, founded by technology industry veterans including CEO Mukesh Chatter. It develops non-flammable, high-performance sodium-ion batteries for stationary storage as an alternative to lithium-ion, with a supply chain built on the US and free-trade partners.

The Na-Series uses a proprietary NFPP+ polyanionic cathode chemistry designed with a physics-informed AI platform that the company says speeds development 15 times. The cells reach 250 Wh/L, cannot enter thermal runaway, operate from minus 40 to 60 degrees Celsius with passive cooling and can be discharged to 0% state of charge. Target uses include AI data centres, utilities, mining, industrial sites, microgrids, defence and commercial buildings.

• NFPP+ chemistry: proprietary sodium-ion cathode with 250 Wh/L energy density.
• Non-flammable: no thermal runaway, tested to UL 9540A at cell level.
• Wide temperature range: minus 40 to 60 degrees Celsius with passive cooling only.
• Full depth of discharge: safe discharge and shipping at 0% state of charge.
• Data centre ready: handles millisecond transients and 800 VDC architectures.
• AI-driven development: physics-informed AI platform for faster battery design.

Data centre operators in Vietnam could deploy non-flammable storage inside or near server halls. Mining and cement sites with high ambient temperatures could replace diesel backup with passive battery systems. Commercial buildings in dense city centres could install storage where lithium-ion permits are difficult.

Non-flammable chemistry allows deployment in places where lithium-ion fire risk is unacceptable, without fire suppression systems. The company notes HVAC and fire-safety components can account for 23-30% of LFP project costs, which passive designs avoid. A 20-year system life supports 15,000 cycles without augmentation, and 100% usable capacity improves asset utilisation.

Concerns over lithium-ion fires and concentrated supply chains are driving interest in sodium-ion for stationary storage. Hot climates and dense urban sites in Southeast Asia add value to batteries that need no active cooling and can be placed close to loads such as data centres and factories.

Headquartered in Malden, Massachusetts. Named one of Fast Company's Next Big Things in Tech 2026. Partnerships in 2026 include a 9 GWh agreement with ERITY for mining, cell production scale-up with Re:Build Manufacturing and a 500 MWh deployment with Juniper Energy.