A Finnish startup's claim to have developed a production-ready solid-state battery has collapsed under independent testing.
Donut Lab raised $25 million and reached a $1.25 billion valuation on the basis of those claims. Third-party tests found its cells use standard lithium-ion chemistry — not the solid-state chemistry the company had advertised. The startup is valued at roughly 50 times what it raised, a multiple that now rests on contested ground.
Investors have funded solid-state battery startups on the premise that someone will eventually crack the chemistry that incumbent lithium-ion can't match. The argument for those valuations requires the claimed technology to actually exist. A gap between advertised chemistry and tested chemistry isn't a delayed timeline — it's a different category of problem.
At $1.25 billion, someone signed off on due diligence. It would be worth knowing what it said.