Donut Lab Simply Turned Up the Warmth on Stable-State Battery Expectations, and the Outcomes are Shocking.

Donut Lab, a Finnish firm, not too long ago launched some spectacular check knowledge demonstrating how their solid-state battery handles excessive temperatures that standard lithium-ion cells would battle to take care of. The check outcomes come from a collection of measurements performed by the VTT Technical Analysis Centre of Finland, a revered, government-backed analysis group. They wanted to determine exactly how excessive the warmth might attain earlier than this Donut Lab cell, rated at 3.6 volts and 26 amp-hours, blew up in smoke (or another method), so that they determined to place it by way of its paces.

The engineers first established a baseline at a cushty 20°C, at which level the cell delivered 24.9 amp-hours of capability throughout a regular 1C discharge (or, to place it one other method, the cell was chucking out a whopping 24 amps in a single hour), however then they ramped up the temperature to 80°C, or ‘excessive warmth’ to you and me, and discharged the cell once more on the similar fee. To their shock, the cell managed to muster 27.5 amp-hours, which is round 110.5% of what it might handle at ambient temperature, after which outperformed that at 100°C (although at a decrease 0.5C fee of 12 amps to maintain issues steady). There, the cell produced 27.6 amp-hours, or 107.1% of the start quantity.

The clear upshot of all of that is that when the temperature elevated, the interior resistance within the stable electrolyte decreased, permitting the ions to maneuver about extra freely, which elevated the battery’s helpful power output considerably. After each excessive discharges, they returned the cell to ambient temperature and recharged it usually; happily, no everlasting injury was found from {the electrical} angle. Not so excellent news: at 100°C, the pouch cell misplaced its vacuum seal, almost definitely owing to gasoline buildup or materials weakening, though it nonetheless functioned correctly.

Standard lithium-ion batteries use liquid electrolytes that develop into wobbly when temperatures rise above 60-70°C, inflicting quite a lot of issues equivalent to vaporisation, swelling, speedy degradation, and, within the worst-case state of affairs, the dreaded thermal runaway, through which the cell turns into so scorching that it’s primarily a fireplace ready to occur. Stable-state designs exchange the liquid with a non-flammable stable, which, for apparent causes, eliminates the supply of all the issues. Donut Lab’s model seems to be capitalising on this benefit, remodeling what can be a significant challenge for different batteries into a little bit however important profit.

This check provides to the proof Donut Lab is utilizing to assist the declare that their battery know-how is appropriate to be used in the actual world. Donut Lab unveiled their Donut Battery as the primary all-solid-state battery pack prepared for vehicles at CES 2026, and it wasn’t only a pipe dream, as they claimed some fairly spectacular numbers, together with 400 watt-hours per kilogram power density, full costs in 5 minutes, and a mind-boggling 100,000 cycles with virtually no fade. The cells are actually powering numerous Verge Bikes fashions that may hit the street this quarter, with the boast that they’ll maintain greater than 99% of capability from -30°C to 100°C.