A recent investigation by YouTuber Ryan Hughes of the Ziroth channel has cast significant doubt on claims made by Finnish startup Donut Lab regarding its alleged breakthrough in solid-state battery technology. The company had promised a production-ready battery capable of five-minute charging, extreme longevity, and high energy density without rare earth materials. However, evidence suggests the startup may have been rebranding existing high-end lithium-ion cells. While Donut Lab maintains that its technical data is accurate, experts and internal reports point to a lack of fundamental battery chemistry knowledge and misleading sourcing from third-party firms.
The controversy centers on the ambitious performance metrics Donut Lab touted for its batteries, which were intended to power Verge Motorcycles. The startup claimed an energy density of 400 watt-hours per kilogram, a figure far exceeding current industry standards. Battery experts have long viewed solid-state technology as the “holy grail” for electric vehicles, but mass production is not expected until the end of the decade. The industry remains skeptical that a small startup could achieve such a feat ahead of major global manufacturers with significantly larger research and development budgets.
Technical analysis provided by Hughes, including data from Finland’s VTT Research Institute, suggests the cells in question behave exactly like standard lithium-ion batteries. Specifically, the expansion curves—which track internal pressure changes during charging—show a distinctive pattern characteristic of graphite-anode lithium-ion cells. Furthermore, the calculated energy density of the tested cells was approximately 298 watt-hours per kilogram, falling well short of the company’s 400 watt-hour claim. These performance metrics are consistent with advanced lithium-ion technology already utilized by major automotive manufacturers, rather than a revolutionary solid-state breakthrough.
The investigation also highlighted internal dysfunction, citing accounts from former affiliates who claimed the company lacked a deep understanding of battery manufacturing. Despite these findings, Donut Lab continues to defend its work, stating it remains on schedule with its technology development. Meanwhile, the broader battery industry continues to advance, with major players like Toyota and CATL pursuing legitimate solid-state research, while current lithium-ion technology continues to see rapid improvements in charging speeds and energy density.