Solid-State Battery Shows Major Breakthrough
Donut Lab's new solid-state battery has demonstrated impressive performance in independent testing, retaining 97.7% of its charge after 10 days. The minimal self-discharge rate is a strong indicator of its potential for long-duration applications in electric vehicles and grid storage.
The recent self-discharge test was the third in a series of independent validations for Donut Lab, conducted by the VTT Technical Research Centre of Finland. Previous tests have already confirmed the battery's capability for ultra-fast charging—reaching 80% in 4.5 minutes—and stable performance at high temperatures up to 100°C. While a typical lithium-ion cell can lose 5% of its charge in the first 24 hours, the Donut Lab battery's voltage drop stabilized significantly after the first few hours of the 10-day test. The cell's voltage only dropped by 12 millivolts over the final 230 hours, indicating a very low steady-state self-discharge rate, a crucial factor for long-term energy storage. This validation adds to a list of bold claims from the company, including a cell-level energy density of 400 Wh/kg and a lifespan of 100,000 cycles. These two key metrics, which would far surpass current industry standards, have not yet been independently tested by VTT. Solid-state technology's core innovation is the replacement of the flammable liquid electrolyte found in conventional lithium-ion batteries with a solid material. This architectural change is what enables the potential for higher energy density, faster and safer charging, and a longer operational life. The Finland-based Donut Lab aims to be the first to bring a production-ready solid-state battery to market. The company has already signed commercial contracts with over ten OEMs and plans its initial deployment in Verge Motorcycles' TS Pro and Ultra models. The company's development is backed by a €25 million seed funding round completed in July 2025. Its board includes notable figures like Risto Siilasmaa, the former chairman of Nokia, lending significant industry credibility to the startup. Major auto and battery manufacturers like Toyota, Samsung, CATL, and QuantumScape are also racing to commercialize solid-state batteries. However, widespread adoption is still hindered by significant challenges in scaling up complex manufacturing processes and reducing the high cost of materials compared to traditional lithium-ion technology.
