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]

 

[NMNeil]

 

[sodamo]

Am I the only one that finds it annoying that someone will post a link without the fore thought to provide at least a sentence of why we should open it? To me that says there was likely nothing of interest, so I don’t.

 

[metroshot]

Am I the only one that finds it annoying that someone will post a link without the fore thought to provide at least a sentence of why we should open it? To me that says there was likely nothing of interest, so I don’t.

That's called clickbait in social media circles.

 

[E90400K]

I'll just say, until this magical donut hole solid state battery is available in the Slate Truck for sale to me, I really don't care.

At this point it's all just internet fodder.

 

[RetiredOnPaper]

The solid state battery story so far; As a lab curiosity it shows the promise of very fast charging, high energy density, safe, light battery. But as a scaled up economical production solution it has been elusive. (It's why chemical engineers earn the big bucks. (or should). Skepticism is healthy and will lead to EV people want to own. You say you got it...prove it.

 

[E90400K]

The solid state battery story so far; As a lab curiosity it shows the promise of very fast charging, high energy density, safe, light battery. But as a scaled up economical production solution it has been elusive. (It's why chemical engineers earn the big bucks. (or should). Skepticism is healthy and will lead to EV people want to own. You say you got it...prove it.

After 20 years and millions of man-hours and billions of dollars of R&D and so far, no real solution for EV. Exactly.

 

[sodamo]

After 20 years and millions of man-hours and billions of dollars of R&D and so far, no real solution for EV. Exactly.

Not exactly limited to EV world. For a few years I followed about every promised advancement in home wind generators, given up. PV wins

 

[RetiredOnPaper]

Not exactly limited to EV world. For a few years I followed about every promised advancement in home wind generators, given up. PV wins

I have a DIY solar generator at our weekend get away. It has run continually for over 3 years. I considered wind but moving parts = problems. I run it separate from the mains, runs my security system, charges my golf cart, ebikes, lawn tractor and soon (I hope) my Slate. Battery pack is LFP 6.5 kwh, set to draw from the mains only when it gets to <5% SOC. I hope to add a few more panels this summer.

 

[E90400K]

I have a DIY solar generator at our weekend get away. It has run continually for over 3 years. I considered wind but moving parts = problems. I run it separate from the mains, runs my security system, charges my golf cart, ebikes, lawn tractor and soon (I hope) my Slate. Battery pack is LFP 6.5 kwh, set to draw from the mains only when it gets to <5% SOC. I hope to add a few more panels this summer.

What brand of lawn tractor do you have? Assuming it's electric.