PV Magazine: Northvolt acquires lithium-metal battery start-up Cuberg

The technology developed by a business spun out of Stanford five years ago could deliver an electrolyte with energy density of more than 1 kWh/l.

This article orignally appeared in PV Magazine.

Marian Willuhn – Swedish battery manufacturer Northvolt is continuing to expand–this time outside Europe. The company has acquired U.S. lithium-metal battery start-up Cuberg and plans to open an R&D center in Silicon Valley. With the acquisition, Northvolt can integrate the start-up's electrolyte technology into its battery systems for considerably improved energy density. Until now, Northvolt has operated in Sweden, Germany, and Poland.

Cuberg – which currently looks to supply the electric aviation sector – claims its batteries deliver 70% more range and capacity than other lithium-ion devices developed for electric aviation. The startup aims to work with Northvolt to mature its technology sufficiently to offer cells with an energy density exceeding 1 kWh/l by 2025. In June, the start-up had its technology tested by Idaho National Laboratory on behalf of the U.S. Department of Energy. The laboratory tested the 5-ampere-hour cells of Cuberg and found they had specific energy of 369 Wh/kg and specific power of 2,000 W/kg.

Lithium-metal batteries substitute heavy graphite in the anode with a lighter metal to cut down on weight, and thus improve gravimetric energy density. Swapping graphite from the anode renders conventional electrolytes unusable, however. A problem that Cuberg claims to have solved with its electrolyte technology that provides stability comparable to that offered by solid-state batteries in its devices.

The start-up was spun out of Stanford University in 2015 and has already attracted high-level customers and investors. The client list includes aviation companies Boeing, BETA Technologies, Ampaire, and VoltAero and Cuberg's backers include Boeing venture capital arm HorizonX Ventures, Activiate.org, the California Energy Commission, the U.S. Department of Energy, and the TomKat Center for Sustainable Energy at Stanford.

“The Cuberg team has shown exceptional ability to develop world-class technology, proven results and an outstanding customer base in a lean and efficient organization,” said Northvolt CEO and co-founder Peter Carlsson. “Combining these strengths with the capabilities and technology of Northvolt allows us to make significant improvements in both performance and safety while driving down cost even further for next-generation battery cells. This is critical for accelerating the shift to fully electric vehicles and responding to the needs of the leading automotive companies within a relevant time frame.”

Northvolt says it can scale the Cuberg technology using its lithium-ion battery manufacturing lines and the partners plan to ship their first batteries to the electric aviation industry within three years. The Silicon Valley research center aims to develop lithium-metal cells further and bring together research from Europe and North America.

“We are very excited to join forces with Northvolt to build the future of clean energy together,” said Cuberg CEO and co-founder Richard Wang. “Northvolt brings incredible technology and manufacturing capabilities that will accelerate the commercialization and adoption of our lithium metal technology. Their deep engineering experience and bold spirit perfectly complement Cuberg's own culture of rapid innovation.”

Northvolt recently announced a $200 million expansion of its production site in Gdansk, Poland, to raise annual production capacity from 5 to 12 GWh. With that step, the factory is on track to become Europe's largest.