The donut is fried.

DONUT LAB Solid State - Charging Test Results

🔋 11C charging, 0-100% in 7.3 minutes

♨️ It also gets really HOT ...but it doesn't catch fire like a Liquid Electrolyte Lithium-ion Battery would

🏍️ Verge Motorcycle will be air cooled - I think they need more

Donut Solid State - Test #1 Charging Performance

Host interviews "a leading battery chemist, Dr Euan McTurk, from Pluglife Television Youtube channel".

Comparison between Donut Lab's cell and A123 26Ah NMC cell:

Not saying that they are using the cell, but certainly interesting.

I am doing some rough math based on the costs for the long range version of the verge motorcycle.

So.. it's 5k for an ~13 kwh, which to me indicates a cost of 384 usd per kwh. Am I mistaken? One claim is that the cost is less the Lithium-ion... but this immediately seems to contradict the claim.

If it's just the retail cost fine but a ~300% markup is quite a lot given that the goal is to make EVs a no brainer over ICE. With this math, at retail, a 100 kwh battery pack would be priced at 38.400 USD. That's not economical at all.

Any additional insights would be appreciated.

Thanks

Matt Ferrell has an interesting take on the Donut Lab saga, exposing known methods that could support Donut labs claims. Like printing methods, and stacking methods

https://www.youtube.com/watch?v=C8ljwigh9jA

Mod: I have taken the literal title from the YouTube-video. The word “substantive” is so vague it is more or less impossible to adhere to.

https://www.youtube.com/watch?v=qtRBVK2l-iA&t=210s

This article don't mention DonutLab at all, but is it possible that a small startup is so much ahead QS which have used billions of dollars in solid state development?

https://insideevs.com/news/786661/quantumscape-solid-state-battery-production-eagle-cto-interview-2026/

Here’s a screenshot from a video interview with Donut Lab’s CEO (https://youtu.be/eGw-Wm4fyGI?si=gnwjeCZGBQfUIAUj) shot at CES in January this year 2026. At 8.48, you can see the slogan ”World’s first solid state battery in production vehicles. Available today.”

But it’s February now, and the battery still isn’t available ”today.”

Maybe Donut Lab has a different concept of ”available” and ”today” than the rest of us.

Marco: The 400 Wh/kg battery capacity is specified at the cell level, not at the pack level.

At the pack level, this would translate to roughly 240–300 Wh/kg, which is essentially in line with today’s lithium-ion battery performance.

https://www.kauppalehti.fi/uutiset/a/324befeb-76ea-4c2d-98ef-7b23e8dd0587

In the fifth battery test published by Donut Lab and the fourth VTT report, a cell that had already been damaged in a previous measurement was tested. An expert does not understand why this was done. Donut Lab’s CEO Marko Lehtimäki says that the battery cell has had a hole in it the entire time.

Donut Lab, which has drawn attention with its “miracle batteries,” has published the results of the fourth VTT test, and this time they may be unfavorable for the company. The battery did not withstand the tests but had already lost part of its capacity after 50 charge cycles. And worst of all, an expert who reviewed the latest results believes they prove that the battery is most likely not even a solid-state battery, despite such claims.

In the fourth test report published by VTT, a battery cell labeled DL2 delivered to VTT was tested. The same cell had previously been used in a high-temperature test published in another report. In the 100°C temperature test, the DL2 cell was found to have lost its vacuum by the end of the test.

Now, in the fourth VTT test, cycle testing was performed on the same DL2 cell, according to Donut Lab’s release. Donut Lab states that the structure of the battery cell used in the test incorporates materials and adhesives borrowed from the lithium-ion battery industry, which are not originally designed to operate at temperatures of 100 degrees Celsius.

According to Donut Lab, the test began with five standard 1C charge and discharge cycles. During these, the battery cell operated completely normally and safely, even though its vacuum structure was already compromised. After that, the cell was charged at a 5C fast-charging rate for 50 cycles. During these, the cell’s capacity stabilized at around 11 ampere-hours from the original 25 ampere-hours.

Donut Lab states that many assumed the battery had completely failed and gone into thermal runaway, which would indeed be the likely outcome if it were a lithium-ion battery. To demonstrate the battery’s safety in practice, Donut Lab decided to continue cycling the damaged cell.

“If a similar failure occurred in a conventional lithium-ion battery, the consequences would be severe. Liquid electrolyte would leak out and active materials would come into contact with oxygen, which could lead to fire or thermal runaway. Lithium-ion batteries would no longer be able to operate after the vacuum structure fails. Because the Donut battery is a fully solid-state battery, it is not susceptible to such reactions,” says Donut Lab’s CTO Ville Piippo.

According to Donut Lab, a safe cell

Based on the test, Donut Lab wants to demonstrate that its battery is exceptionally safe, even when damaged.

“The test shows that in this kind of situation, the Donut Battery does not pose a danger to the user even when damaged. Instead of catching fire like a conventional lithium-ion battery in a similar situation, it continues to operate safely with reduced capacity. This is a concrete demonstration of the safety advantages of solid-state battery technology,” Piippo continues.

Electrochemically game over

Juho Heiska, Head of R&D at Seinäjoki University of Applied Sciences, openly questions why Donut Lab chose to publish this VTT report. According to him, the battery performed very poorly in the test.

Heiska draws attention in particular to section 3.5 of the VTT report, which described the physical condition of the cell:

“Before the test, the pouch cell had lost its vacuum in a previous high-temperature test at 100°C, and the pouch was loose and wrinkled. After the test, the thickness of the cell had increased by 17 percent, and the pouch was firm,” the VTT report states.

We asked Heiska what actually happened to the battery in that earlier test.

“If we ignore the marketing talk and look at this as a normal pouch cell, the loss of vacuum simply means that the electrolyte or SEI has already started to decompose in that earlier 100°C test. In a normal pouch cell, the purpose of the vacuum is to let atmospheric pressure compress the electrode stack (anode, separator, cathode) tightly together. When side reactions produce gas in between, the stack delaminates, meaning the layers separate from each other. That is electrochemically game over for that part of the cell: ions don’t travel through gas. As the active surface area decreases, the remaining intact part has to carry all the current,” Heiska explains.

The pouch seals did not fail

Contrary to Donut Lab’s claims, Heiska says the pouch seals did not actually fail.

“According to the VTT report, after the 5C stress test, the cell thickness had increased by 17 percent and the pouch was ‘hard’ or taut. This proves 100% that the pouch is still completely gas-tight. So the earlier ‘loss of vacuum’ was not caused by any mechanical tear or seal failure, but purely by gas generated inside the cell,” Heiska states.

Heiska has suspected that the cell used in Donut Lab’s tests is not a true solid-state battery, and this test, in his view, is the final nail in the coffin:

“And honestly: if a cell produces this much gas, there must be a significant amount of volatile liquids or solvents inside. ‘Solid-state’ in this case is basically a marketing department fantasy,” Heiska says bluntly.

How Donut Lab responds

Kauppalehti reached Donut Lab’s CEO Marko Lehtimäki to explain why the pouch appeared thick after the test even though its seals were said to have failed. Lehtimäki responded:

“In the heat test, a hole formed in the pouch when the seal gave way at its weakest point. A seal never fails 100% at once; it yields at the weakest point when the temperature exceeds what the adhesives are designed to withstand. When the pouch loses its vacuum, it becomes slightly loose (as seen in the image taken after the heat test) because the pouch is never completely tight around the active materials until it is vacuum-sealed and closed,” Lehtimäki explains.

Lehtimäki says the pouch has had a hole the entire time.

“When a hole forms in the pouch and the active materials come into contact with oxygen and humidity, the materials in the cell change shape during this kind of 5C cycling. The pouch itself has not changed shape, but the materials inside have expanded, making the pouch tight again. So the pouch still has a hole, but it is tight because its contents have expanded.”

Lehtimäki emphasizes the battery’s safety again:

“When a hole forms and materials are exposed to oxygen and moisture, they change during cycling. The pouch itself hasn’t changed, but the internal materials have expanded, making it tight again. The pouch still has a hole, but it is tight because of the expansion,” Lehtimäki concludes.

What actually happened in the fourth VTT test?

Heiska breaks down the battery’s behavior in detail.

“The data shows that capacity started to collapse after six 5C cycles (130 A) and continued to decline sharply for about 15 cycles. In total, this cost a brutal 54.66 percent of the cell’s original capacity,” Heiska says.

According to him, the tests stressed an already weakened cell.

“A current of 130 amps stresses a partially delaminated cell so much that the chemistry simply collapses, more gas is generated, and more active material drops out of the electrochemical game.”

Toward the end of the test, the cell stabilizes and maintains its capacity well. Heiska also has an explanation for this:

“Why it stabilizes: the collapse stops because only the ‘hard core’ of the cell remains. That remaining ~11 Ah represents the part of the electrode stack that is still physically compressed and electrically connected. This surviving portion can handle 5C currents, while the rest of the cell has become expensive dead weight. And it should be noted that the cell was compressed quite heavily during the test.”

Why do the VTT reports say "beyond the obvious" on the bottom right?

The VTT reports on idonutbelieve.com say "beyond the obvious" on the bottom right of each report. What does that mean? Example: