Why Donut labs solid state battery could be real

[HC_79]

Donut Labs has just released an independent report on their new battery. According to Donut Labs, the first independent test of the Donut Solid State Battery (see link), conducted by VTT Technical Research Centre of Finland, evaluates its charge performance under demanding conditions without active cooling. The cell was tested at both 5C and extreme 11C charge rates, confirming previously stated fast-charging targets, including a 0–80% charge in just 4.5 minutes at 11C. The results demonstrate exceptional charging capability alongside stable thermal behavior, providing verification of the battery’s high-power performance.

• VTT testing confirmed the Donut Battery charges from 0–80% in 4.5 minutes at 11C rates without active cooling
• The battery retained 98.4–99.6% of charged capacityafter rapid charging at extreme speeds
• No special compression or active cooling is required, simplifying battery pack design and reducing costs
• At 5C charging rates, the cell reached 100% in just over 12 minutes with full capacity available on discharge

I Donut Believe - Presenting Third Party Results

The place where independent analysis of Donut Lab’s solid-state battery claims, with public test data, reports, and technical commentary is released.

idonutbelieve.com

Every Monday, Donut Labs will release results of VTT's testing of its battery. If the independent testing confirms Donut Labs claims, this battery will revolutionize EVs.

I'm still skeptical and just because you can push it to 11C in testing doesn't mean that will ever happen in the real world due to maintaining battery longevity etc. Also, the tests are still conducted in a very controlled scenario and don't reflect real world use. I'm sure other companies making Solid State batteries can yield the same results on internal testing but they've stated numerous times that's not the problem. The challenge has always been about getting it in the real world and scaleable.

QuantumScape on the other hand has delivered 4C charging and shown the battery retaining 95% health after 1000 charging cycles

QuantumScape’s solid-state battery cell achieves milestone in testing: 1,000 charging cycles

In recent A-sample tests at the laboratories of PowerCo, the Volkswagen Group’s battery company, a solid-state battery from QuantumScape achieved more than 1,000 charging cycles while retaining more than 95 percent capacity. This translates to a potential battery life of 500,000 km with no...

chargedevs.com

 

[HC_79]

If it can be reliably manuactured in large enough quantities.

. Any company can show off what they're doing in a controlled environment. Come back to us when you've learnt how to manufacture it at scale!

 

[LuHart]

yup, lots of IFs, but potentially very promising.

 

[limtless]

Donut Labs has just released an independent report on their new battery. According to Donut Labs, the first independent test of the Donut Solid State Battery (see link), conducted by VTT Technical Research Centre of Finland, evaluates its charge performance under demanding conditions without active cooling. The cell was tested at both 5C and extreme 11C charge rates, confirming previously stated fast-charging targets, including a 0–80% charge in just 4.5 minutes at 11C. The results demonstrate exceptional charging capability alongside stable thermal behavior, providing verification of the battery’s high-power performance.

• VTT testing confirmed the Donut Battery charges from 0–80% in 4.5 minutes at 11C rates without active cooling
• The battery retained 98.4–99.6% of charged capacityafter rapid charging at extreme speeds
• No special compression or active cooling is required, simplifying battery pack design and reducing costs
• At 5C charging rates, the cell reached 100% in just over 12 minutes with full capacity available on discharge

I Donut Believe - Presenting Third Party Results

The place where independent analysis of Donut Lab’s solid-state battery claims, with public test data, reports, and technical commentary is released.

idonutbelieve.com

Every Monday, Donut Labs will release results of VTT's testing of its battery. If the independent testing confirms Donut Labs claims, this battery will revolutionize EVs.

What's the energy density? All the rest is standard capacitor rates. Until they put it in an EV and drive more than 100ft this doesn't really mean anything. I am going to guess it has no range and would empty rapidly once you tried to draw significant voltage.

 

[DeaneG]

What's the energy density? All the rest is standard capacitor rates. Until they put it in an EV and drive more than 100ft this doesn't really mean anything. I am going to guess it has no range and would empty rapidly once you tried to draw significant voltage.

The cell under test looked to me to be very roughly 15cm x 6cm x 1cm, or about 0.1L. Capacity was about 100Wh, so very roughly about 1000Wh/L energy density. NMC lithium cells are usually in the 500-700Wh/L range.

 

[LuHart]

Donut Labs claims energy density of 400 Wh/kg

 

[LuHart]

So that’s about 2x NMC lithium cells. But testing by VTT will confirm all the technical details and claims.

 

[Dolphins4ever]

I'm still skeptical and just because you can push it to 11C in testing doesn't mean that will ever happen in the real world due to maintaining battery longevity etc. Also, the tests are still conducted in a very controlled scenario and don't reflect real world use. I'm sure other companies making Solid State batteries can yield the same results on internal testing but they've stated numerous times that's not the problem. The challenge has always been about getting it in the real world and scaleable.

QuantumScape on the other hand has delivered 4C charging and shown the battery retaining 95% health after 1000 charging cycles

QuantumScape’s solid-state battery cell achieves milestone in testing: 1,000 charging cycles

In recent A-sample tests at the laboratories of PowerCo, the Volkswagen Group’s battery company, a solid-state battery from QuantumScape achieved more than 1,000 charging cycles while retaining more than 95 percent capacity. This translates to a potential battery life of 500,000 km with no...

chargedevs.com

Yes, this is all future charger infrastructure, except maybe if in semis and they build out megawatt level chargers. Otherwise about 2.3c roughly is what a 400kw (rare still today) is what a 175kwh pack could charge, but that is about the very rough energy a pack could be in Lucid’s gravity lots of assumptions, but based on the size of the cell and average volume capacity of a pack/cells ratio. So, potentially gravity could have 50% more range and at the 400 kw charger do a 0-80% in just over 20 minutes and a 0-100 in just under 30 minutes. All for supposedly the current battery cost. YES, more data needed, but this shows a very battery like charge and discharge pattern, so not a super capacitor. You can rough an energy density of about 895 wh/l. This was the big unknown and really strong like a ssb should be, but they ignored answering questions about this metric, so people thought - yeah higher power but crap density, which appears incorrect now. Did this come out as good as what donut touted at ces, no…but the difference in full charge being 5 minutes or 7 minutes isn’t a big miss until we can charge at that capacity. I want to see 400 wh/kg verified, which just weighing that cell could have given that info, oh well next week maybe. Cycle life, degradation, discharge rate, temp effects, elements confirmed, production error rate/% usable product and this is real and now and most other battery tech is worthless because nothing slated to come online for the next 5-10years can match on performance, composition elements, cost or some combination of the three. There is billions of reasons catl is calling this bs as there business would go to zero rapidly

 

[Dolphins4ever]

. Any company can show off what they're doing in a controlled environment. Come back to us when you've learnt how to manufacture it at scale!

My understanding is they are supplying it in about 30,000 motorcycles starting now and their ces announcement was they can make gigawatt amount now for any orders and can “easily scale more.” Nobody else is doing even semi ssb at this capacity now. This would be leaked as bs by now with every battery using manufacturer would be seriously talking with them and getting contracts lined up, touring manufacturer facilities, etc. all under nda, but generality that it is vaporware would leak.

 

[Dolphins4ever]

What's the energy density? All the rest is standard capacitor rates. Until they put it in an EV and drive more than 100ft this doesn't really mean anything. I am going to guess it has no range and would empty rapidly once you tried to draw significant voltage.

Stored energy is stored energy. If their 400 wh/kg holds combined with the demonstrated ~895 wh/l. It should supply energy as any energy storage. Does it dissipate quickly overnight, probably not, but I expect that type of data to come. The charge/discharge curve looks like a battery and not a capacitor. A few more very key studies, but charging at rates where today’s tech would at best ail and worst undergo thermal runaway is impressive, because it is on the order of what they originally disclosed at ces. That is a step in boosting their credibility for the other claims. Also, not hearing any leaked I saw donut’s manufacturing and it is bs. There must be 100s that have done diligence on this since ces and by now I think bs would be leaking into journalism by now.

 

[gaskiller]

They didn't demonstrate in a car, why a motorcycle? I'm not convinced.

 

[borski]

They didn't demonstrate in a car, why a motorcycle? I'm not convinced.

Because it worked in a motorcycle and that's a smaller problem.

I have no idea if it's going to work at scale.

But I sure hope it does. I'm all for lighter EVs with faster charging. Hell yeah.

 

[tmichael]

I believe it is an issue of when, not if, the technology arrives in production automobiles. My grandkids and I just took a walk through the Henry Ford Museum of American Innovaton in Dearborn, MI. The development of steam engines to internal combustion to electric power for automobiles took over a hundred years.

However, technology has increased speed of development at logarithmic speeds. I have a glass topped table in my office at home with computer storage devices displayed. It starts with a 10 MB hard drive, coated with magnetic material showing obvious bad sectors where the coating didn't adhere to the disc. The mechanical examples end with a highly polished 100 GB, small form factor, mirror finished drive. Then comes the early Silicon of PCI days, ending in mini SD drives of 256 GB. The time between the pieces is about 30 years.

We aren't at the beginning of new battery technology - it might not be in the next 5 years for mass production, but it sure isn't going to take 20 years...

America at its best!

 

[DeaneG]

Hopefully, science at its best. Donut Labs is based in Finland, and may be using technology from Nordik Nano, also Finnish.
BTW the first hard drive I ever designed into a product was 5MB, kind of a big deal, we could store dozens of files on it at a time.

 

[tmichael]

Hopefully, science at its best. Donut Labs is based in Finland, and may be using technology from Nordik Nano, also Finnish.
BTW the first hard drive I ever designed into a product was 5MB, kind of a big deal, we could store dozens of files on it at a time.

I still have 160K floppies and started playing on a Sinclair in England, running basic.

Of course, that was before software bloat....

Did I mention that I had to walk to school, uphill both ways, with only newspapers for shoes?

 

[Dolphins4ever]

They didn't demonstrate in a car, why a motorcycle? I'm not convinced.

I don’t know, but probably an opportunity to make revs and also get along with their major investor - who also is a major investor in the motorcycle company. VCs arrange these relationship deals all the time specifically to make both of their investments more valuable, Occam’s razor, but could be other reasons. I have a trust but verify attitude (and with the released data from a 3rd party verification so far supporting their claims, it earns more trust in my book), but that is just me.

 

[scal_air]

I still have 160K floppies and started playing on a Sinclair in England, running basic.

Of course, that was before software bloat....

Did I mention that I had to walk to school, uphill both ways, with only newspapers for shoes?

You forgot that it was deep snow going to school.and blazing hot sun going home.

Article regarding independent testing results (so far)
https://electrek.co/2026/02/23/donut-lab-vtt-solid-state-battery-test-results-fast-charging/

My often used example is the flat screen TV. 42" Philips plasma for $15K circa 1998. Now, less than 30 years later, you can find one starting at $150. Let that sink in....

 

[Pragmatic]

At least you had newspapers.

 

[borski]

I still have 160K floppies and started playing on a Sinclair in England, running basic.

Of course, that was before software bloat....

Did I mention that I had to walk to school, uphill both ways, with only newspapers for shoes?

What’s a newspaper

Is that like a blog

 

[tmichael]

You forgot that it was deep snow going to school.and blazing hot sun going home.

Article regarding independent testing results (so far)
https://electrek.co/2026/02/23/donut-lab-vtt-solid-state-battery-test-results-fast-charging/

My often used example is the flat screen TV. 42" Philips plasma for $15K circa 1998. Now, less than 30 years later, you can find one starting at $150. Let that sink in....

...and for you youngsters, that is around $30K in current dollars.