Donut Lab presents first data on controversial solid-state battery
During its premiere at CES , the Finnish company shared only limited data about its potentially groundbreaking product. Key figures included an energy density of 400 Wh/kg, a charging time of five minutes for a full charge (not just 10–80%), and a lifespan of 100,000 cycles. The combination of these figures raised eyebrows—historically, significant improvements in energy density and charging speed have required trade-offs in durability.
What is happening
However, as the trade show in Las Vegas only featured mock-ups of the alleged solid-state battery and no further details from the company, many questions about how Donut Lab achieved these impressive figures remained unanswered. In the aftermath, experts and YouTubers cast doubt on the development, while battery manufacturers expressed scepticism. "All the parameters contradict each other… Anyone with even a basic understanding of this technology would think it’s a scam," said Yang Hongxin, CEO of the Chinese battery manufacturer Svolt. "If we had presented full third-party validation right away, the controversy wouldn’t have ended—it would have simply shifted," says Marko Lehtimäki, CEO and co-founder of Donut Lab.
Why this matters for transport
"If certain people don’t like the conclusion, they simply move the goalposts. If we had proven the technology works, they would have questioned its scalability. And scalability is the perfect breeding ground for doubt because it takes months or years to provide irrefutable evidence." Such persistent scepticism would have made it significantly more difficult to secure funding for actual scaling. For this reason, Donut Lab made a deliberate decision ahead of the technology’s launch.
What to watch next
"We let the loudest voices in the industry speak first and spread the narrative that this technology simply cannot exist today. This way, everyone outside the battery sector can understand the magnitude of the breakthrough we aim to bring to market," explains Lehtimäki. The logic is that Donut Lab can then silence these sceptics by presenting proof of its technology.