A three-person clean energy team in Seattle is chasing China in pursuit of an increasingly popular alternative to traditional lithium-ion batteries. Emerald Battery Labs, a startup working out of the University of Washington, recently raised just under $1.1 million in a pre-seed round to continue scaling its sodium-ion battery technology.
The burgeoning energy storage option avoids the use of lithium, which is highly sought, difficult to extract and has limited U.S. production. Sodium, by comparison, is much cheaper and comes from the same element that’s in table salt. The sodium-ion batteries also last longer and present fewer fire concerns.
Battery demand is rising rapidly as these systems pair with renewable, intermittent sources like sun and wind; enhance hydro dam capacity; provide backup power for data centers; power drones and defense devices; and work with EV charging stations to reduce grid strain during peak demand.
“As battery chemistries evolve, as technology evolves, people are going to find new ways to use energy storage technology,” said David Bell, Emerald’s co-founder and chief product officer.
Growing interest
A recent Sightline Climate survey of investors and entrepreneurs in climate tech selected sodium-ion batteries as a top-pick for a 2026 breakthrough technology, coming in just behind the use of AI for clean tech materials discovery.
But there’s already a clear leader in the space.
“China, with its powerful EV industry, has led the early push” into sodium-powered batteries, according to MIT Technology Review.
Chinese auto and battery makers Contemporary Amperex Technology Co. Ltd., or CATL, and BYD are in hot pursuit of the technology, MIT reports. CATL claims to have a sodium-ion battery line operating at scale, while BYD is building its own massive production facility.
U.S. competitors include Peak Energy, Nanode Battery Technologies and Unigrid.
While this alternative chemistry offers numerous benefits, there’s an important trade off: it’s less energy dense — meaning sodium-ion batteries need to be larger than competing technologies to deliver the same amount of power.
Emerald’s path forward
Emerald is operating out of the UW’s CoMotion Labs and using the university’s Clean Energy Testbeds for fabrication work. The startup is scaling production and looking for partners to pilot test its products.
It plans to hire additional employees in the coming year. Emerald’s investors include Seattle-based E8, a network of angel investors that backs clean-tech companies; network members who directly invested; and an undisclosed family venture office.
Emerald’s founders bring deep battery experience:
- Bell led product management and customer programs at Group14, which is manufacturing next generation silicon-anode materials for lithium-ion batteries, and worked at Ionic Materials.
- Kjell Schroder, CEO and chief technologist, held leadership roles at Form Energy, Ionic and EnPower.
- Aric Stocks, chief operating officer, is a trained materials engineer and former global business development leader at Group14.
