An Intertek lab in the UK found just 3.4 ppm of lithium in a sample of Donut Lab’s “solid-state” battery, and the Finnish startup is now using that result to argue its cell is neither lithium-ion nor sodium-ion.

But the report measured just two elements, on a cell Donut Lab took apart itself. And nine months after CES, there’s still no production vehicle running on the battery.

Donut Lab has published a new independent test claiming its battery reached an energy density of 409 Wh/kg and 805 Wh/L, the first energy-density figure the company has put on record after months of scrutiny.

But the number lands against a promise the company has already broken: that this “solid-state” cell was in production and ready to power a production EV by the end of Q1 2026. It isn’t, and it wasn’t.