The Donut Story Continues.

[KevinRS]

SS battery tech is years away from any practical use.

With the amount of heat generated per cell, I'd say it's a car fire spreading to a house fire waiting to happen.

Donut Lab’s ‘miracle’ solid-state battery confirms 0-80% charge in 4.5 min — but there’s a catch.....

https://electrek.co/2026/02/23/donut-lab-vtt-solid-state-battery-test-results-fast-charging/

Well, that much heat is from charging 80% in 5 minutes, I think any battery architecture is going to have heat on that order charging that ridiculously fast. Charging that fast for a 4 wheeled vehicle scale battery would need a really high powered charger, with high voltage and current on heavy cables, would need some active cooling at high rates as well.
That is the part no one was really saying was impossible, but the capacity and charging cycles don't seem to be compatible, especially with those rates. The electrolyte is solid, and if it cracks from the heat cycling you've got a problem.

 

[NMNeil]

A supercapacitor doesn't have a voltage curve like that when charging. It would be a straight line. This voltage curve slopes up at the top just like a battery normally would. A supercapacitor would also be the size of a large car battery to take that much energy.

But claiming 100,000 cycles does put it in super capacitor territory and Nordic Nano develops materials for super capacitors and they joined forces with Donut.
It'll be interesting if they ever actually offer a battery for sale then we can take it apart and see what's inside, but I can't see that happening anytime soon.

 

[KevinRS]

Supercapacitors do have a large cycle life and fast charge/discharge rate. But they have lower voltage limits, and lower charge densities than batteries. That is the thing about their claims. It's like they cherry picked the best theoretical stats of several different technologies and claimed to be able to match them all at once.

 

[bartflossom]

 

[bartflossom]

 

[bartflossom]