Finnish startup Donut Lab’s battery proven to be lithium-ion

A Finnish battery startup that claimed to have achieved a breakthrough in energy storage technology is facing allegations of a major fraud, with a new investigation concluding its product is a conventional lithium-ion battery, not the revolutionary solid-state cell it promised. The findings, based on electrochemical evidence reviewed by more than 20 independent experts, raise serious questions about claims that attracted millions in investment and briefly propelled the company's valuation to over a billion euros.

The company, Donut Lab, unveiled its so-called "Donut battery" at the CES trade show in January 2026, announcing it as the world's first production-ready solid-state battery. The company claimed the sodium-ion cell offered an energy density of 400 watt-hours per kilogram, a 100,000-cycle lifespan, and ultra-fast charging. It promoted the technology as the power source for a limited batch of Verge TS Pro electric motorcycles, with deliveries expected in the first quarter of 2026.

Skepticism emerged quickly, and an investigation led by battery researcher Ryan Inis Hughes, known online as Ziroth, has now presented technical evidence that the battery is lithium-ion. The...