Posted on 02/25/2026 8:02:48 AM PST by GenXPolymath
Donut Lab commissioned VTT to validate its bold solid-state claims, and the results show near-full capacity retention even after ultra-fast charging...
Rapid charging under test
VTT Technical Research Centre ran the tests in what engineers described as a worst-case scenario.
The lab did not use active temperature controls. It also let the cell’s heat rise freely at high charging rates.
Experts measured performance using C-rates, where 1C equals a one-hour charge from empty to full.
Under that scale, 5C roughly equals a 12-minute charge, and 11C is about a five- to six-minute charge.
The process began with a standard discharge test at 1C. Rapid charging followed at 5C and 11C under both cooling configurations.
At 5C, the battery held up well, reaching 80% state of charge in about 9.5 minutes and 100% in just over 12 minutes.
After discharge, the cell retained all its stored energy. These results align with the five-minute charge claim the company previously announced.
Extreme speeds, full capacity
Donut Lab then pushed the cell to even higher charging rates. At an 11C rate, the battery reached 80% charge in 4.5 minutes. It hit full capacity in just over seven minutes.
When discharged after this rapid charge, the cell retained between 98.4% and 99.6% of the energy it had stored.
These figures show the battery’s ability to handle intense power input without huge losses.
Unlike many solid-state concepts being developed in labs, Donut Lab’s design performed these tests without requiring active cooling systems.
It also did not need unusual pressure or compressive force on the cell to work effectively.
The curve should look like a lithium chemistry because it is.
The take away should be they did it without active liquid cooling or having to hold the cell in a pressure binding to keep it from swelling and venting gases. 11C is no joke that’s 5 min full charges again you only go to 80% in lithium chemistry because of the way the ions stack up in the anode as it gets close to full they jam in and things start to shift at the atomic level repeatedly doing this causes degradation of the anode. This is gonna be true of most lithium anodes be them metal, carbon,graphite,silicon, silicon carbide, it’s a function of the lithium ion itself.
11C while not the 66C aluminum graphene cells have demonstrated is still plenty good for consumer devices. That’s a smartphone off a USB 3 charger from zero to full(80%) in 5 min. That alone makes for a huge global market. The fact that it’s 400wh/kg vs 160 or 220 is icing on the cake. That nearly doubles you smartphones capacity.
It was not all that long ago that lithium was 100wh/kg and those cells launched the modern smartphone era. Each generation of lithium has been better than the last, this is the next logical step. Take out the flammable liquid electrolyte and put in nanoglass or ceramic. The anode and cathode chemistry is well known already.
The secret sauce is how to get lithium ions through said nanoglass or ceramic from the anode to the cathode.
My problem is it is an extreme claim and little is known, no papers actually spelling out the science behind it and where are the patent claims?
Am I missing something or do the papers and patent claims exist?
Awful big leap with little supporting it. Nice seeing an independent study but why does this come across so sketchy as well? There seems to be a lot missing in this article.
I have not been keeping up with this closely. Was Donut Labs claiming they did not use lithium?
This was a major point in the video I saw. I'll see if I can find that video again. It was one of the well known youtubers.
Oksay, then why wasn’t that the headline?
+1.
I’ll wait until they know what the life of that battery is before getting excited.
People who don’t own or use an EV or lots of portable devices lack the knowledge to know that lithium chemistry is really 20% to 80% state of charge SOC.
This is properly called it’s operating window. Outside this window and SOH state of health degrades at a much faster rate.
LFP cells do 0-100% windows but that cuts the cycle life down to 3000 or so doing 100-50 which is 50% DOD cycles the cycle life jumps to 20,000 at 1C drop that to 1/4C discharge and charge rates and it’s 30,000 a ten times increase.
https://www.powertechsystems.eu/new-high-performance-lithium-lifepo4-cells/
This is why having 98-99% after an abusive 11C uncooled charger is impressive.
Donut showed SOH curves for regular 1 & 5C rates they go asymptotic after the first few hundred cycles. They extrapolated it out to 100,000 cycles until 80% SOH
No surprise there is little to break or degrade in a solid anode, solid nanoglass, solid cathode system only the ions need to move and if you have strong ion cages they can law a looooooonnnnggggg time.
For comparison sodium ion cells have hit 50,000 cycles due to Prussian Blue cathode’s cages being smaller than the sodium ion entering them there is virtually zero atom stresses.
Thanks for posting this.
“Does the last 20% take far longer time?”
It takes long enough they don’t want to talk about it.
Are the SS batteries a fire hazard like the lithium ion batteries?
Why do they not give the time for 100% charge? Does the last 20% take far longer time? Always question why they report in this manner, because there is a reason that they report it as they do.
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They did, you have to read more than the first line to see it though. This is from the article:
“Donut Lab then pushed the cell to even higher charging rates. At an 11C rate, the battery reached 80% charge in 4.5 minutes. It hit full capacity in just over seven minutes.”
Yes, I just looked they are nanoglass really a ceramic matrix and sodium is the charge carrier they didn’t show if it’s the ion form or metal form in the anode. Either would work in a solidus matrix of glass or ceramic.
Sodium and lithium are in the same column on the periodic table which is really just a electron shell org chart. Sodium has very similar electrochemical properties but a slightly larger electron shell radius which means it’s ionic radius is also larger you need bigger “cages” in your cathode and if it’s not metal anode then an ion receptor cage there too.
Sodium changes the game from a resource limit view. Even more exciting with sodium in the mix.
Sodium charge curves should look like lithium it’s blood brother being so close in electron shell config.
What this really does is light the fire under BYD and CATL to up their game. Both have the manufacturing giant plants to crank out cells by the gigawatts worth. Donut could just licence them the rights and take it to the bank. Honestly that’s what I would do. Sell the rights get super rich off it and retire to an island in the Southern hemisphere so when the nukes fly the Hadley cell keeps all that fallout in the Northern hemisphere.
That makes it more exciting as sodium chloride is pennys per kg vs $$ for lithium carbonate.
“Are the SS batteries a fire hazard like the lithium ion batteries?”
No there is nothing to burn they are solid like rocks or glass.
Battery fires are liquid electrolyte fires the solid anode and cathodes don’t tend to burn. I mean graphite if you get it hot enough can burn but so can plastic and even aluminum for that matter. Ask the Brits about aluminum hulled ships.
BS! I’ve seen so much con and fraud in these claims, I don’t believe a word of it.
I agree, and thank you for pointing out how sodium would appear so similar to lithium in it's charge/discharge profile.
Sodium is far more plentiful and easy to obtain than lithium.
We may be facing a future in which we have actually good batteries with better capacity, far greater life expectancy, and just a better storage system all around.
A lot of my concerns about Electric Vehicles may be suddenly getting addressed and resolved.
Of course we still have "the government controlling them" problem, which won't be resolved through chemistry.
“I’ll wait until they know what the life of that battery is before getting excited.”
They have shown SOH aka capacity retention curves for 1C and 5C they are into the 100,000 cycles range.
Given that existing sodium Prussian Blue cells have demonstrated 50,000 cycles and those are with liquid electrolyte which degrades over time.
These sodium solid state cells would have little to degrade. Most batteries fail from either the anode or.cathode getting damaged at the atomic level from.cramming ions in and out or the electrolytes degrade and breakdown from heat and age. Solid state cell eliminate the latter and without having to be bathed in acidic or basic fluids under heat and pressure the anode and cathode is in much more friendly environment. No shock that a solid state sodium cell could do 100,000 cycles to it’s 80% SOH and “end of service life”
There is a while market for second life cells once cells reach 80% SOH they are pulled form service in an EV pack. Those cells get grouped by internal ohms of resistance so they will charge balance and turned into powerwalls where they do another 3000+ cycles down to 50% SOH and then they go to Redwood Inc to be shredded into black mass and the lithium, nickel and cobalt recovered. Fun fact Redwood is run by former Tesla battery engineers who unsurprisingly recycle EOL lithium cells. They take any cell not just EV they have a mail in program for any cell, former power tools, laptops, phones, tablets. They are the largest domestic source of battery chemicals in the USA right now. You import them or you ask nicely for redwood to sell you some.
What size was the battery and capacity? i mean was it a AA cell? An EV size battery? Not enough info unless i skiopped a paragraph....I’ll try tio look it over again.
This is what my wife needs for her cell phone. She is always running her battery down, constantly recharging it.
“BS! I’ve seen so much con and fraud in these claims, I don’t believe a word of it.”
I guess you missed this was the third party independent testing to show hey we at least have a lab grade device.
The real question is are they going to sell the rights and who buys them can sit on them or not. This very much threatens BYD and CATL they could just buy it and sit on it till they are ready to do solid state cell themselves or they could buy it and bring them by the gigawatts hours worth to the market and dominate it. Given they already dominate the lithium and now sodium ion markets I expect them to buy it steal this tech and run with it. This is a trillion dollars plus market the world runs on energy storage devices.
I give it a year before one or both BYD and CATL announce they too have sodium solid cells that fast charge how they get there is only a matter of money and/or espionage
Either way these types of cells are coming Toyota has some in 2027 slated for production use they are testing them now.
Benz bought a competing group and is also doing testing right now as preproduction.
This is just the next step in battery evolution.
Nicads gave way to Ni metal hydride then Dr Goodenough and his team invented lithium ion which the whole world said was impossible and you will never cross 100wh/kg they won the Nobel Prize in chemistry for it. Those 100wh cells sparked the modern world with smartphones, and laptops that were impossible. Lots and lots of crow was eaten. Those lithium ion actual ion cells gave way to NMC then LFP joined the party. Now sodium ion are roaring into the scene CATL is the world leader. -40C and no loss of charge, 10000-50000 cycle lifetimes and sodium ions can’t thermal runaway. Guess what sodium solid state is not coming it’s here the only question is who brings it to the trillion dollars plus market first.
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