Donut Lab alleged Solid State Battery launched at CES 2026

[EEVblog]

There's actually quite a lot of publicly funded research in the EU (and Britain) into sodium ion capacitors and hybrids. Nordic Nano not part of it, but they likely used that as inspiration for their pitch.

So there is, but I thought the energy density was poor compared to even regular lithium ion, and so they aren't really a practical thing?

[Marco]

This might also be in the too good to be true region, but this paper claims a hybrid with 247 Wh per kg (made possible mostly by the cathode surface area).

https://www.sciencedirect.com/science/article/abs/pii/S2405829724001958

[Randy222]

Judging on the "charging demo" clip , their technology is a Resistor. This is the only technology the "demonstrated"  charging profile fits (no change in voltage and no change in current over the charging cycle).

But there are IC's for supercap charging that can do CC and CV modes. Having both I and V stuck on a # does not make sense though.

https://www.mouser.com/datasheet/2/256/MAX17701-1888136.pdf

[tszaboo]

There's actually quite a lot of publicly funded research in the EU (and Britain) into sodium ion capacitors and hybrids. Nordic Nano not part of it, but they likely used that as inspiration for their pitch.

So there is, but I thought the energy density was poor compared to even regular lithium ion, and so they aren't really a practical thing?

Around 1500mAh in a 18650 cell, with 3v average voltage.
It's not an energy density champion, but the price can drop very low with volume. I think they already going into electric cars in China. And it has other benefits.

[Electrodynamic]

Maybe they call it "solid-state" because what they have does not meet the well-known definition of battery.

There are only two ways to store energy in this case, either electrostatic (SuperCap), or in electrochemical form (battery). It's either one or the other.

Agreed but there could more to it imo.

Imagine your hands are the flat electrodes of a capacitor and in between them the electrolyte forming a dual layer capacitor. The capacity is limited because the electrode surface area is limited. Now imagine we could engineer the electrode material with specific peaks and valleys like our fingers being interlocked. We could easily quadruple the surface area and capacity. If we made the engineered material of something like porous graphene then the total surface area could be what's outside our interlocked fingers and inside them.

In other words, we don't know what the maximum capacity per unit volume is because we don't know how far we can extend the surface area inward. We could have smaller peaks and valleys on the surface of the larger peaks and valleys all within a three dimensional porous framework.

I think it could be done with something like roll to roll CVD graphene followed by high speed laser etching/lithography. The science is sound and the technology known.

[Randy222]

Maybe they call it "solid-state" because what they have does not meet the well-known definition of battery.

There are only two ways to store energy in this case, either electrostatic (SuperCap), or in electrochemical form (battery). It's either one or the other.

Perhaps, but neither of them are solid-state things. To call a supercap "solid-state" or a "battery" is just wrong.
If there are hybrid versions, then the thingy pack should be labeled according to 1) how the electrons are created, and 2) how the useable charge is stored.

I think the best way to frame this cap tech, is to start with some agreed-upon definitions, go from there.

What is solid-state?
Solid-state is a common descriptor used to refer to electronic components, devices and systems based entirely on semiconductor materials such as silicon, germanium or gallium arsenide. The term solid-state was especially prevalent in the late 1950s and early 1960s, during the transition from vacuum tube technology to the diode and transistor.

[Randy222]

There's actually quite a lot of publicly funded research in the EU (and Britain) into sodium ion capacitors and hybrids. Nordic Nano not part of it, but they likely used that as inspiration for their pitch.

So there is, but I thought the energy density was poor compared to even regular lithium ion, and so they aren't really a practical thing?

Around 1500mAh in a 18650 cell, with 3v average voltage.
It's not an energy density champion, but the price can drop very low with volume. I think they already going into electric cars in China. And it has other benefits.

I thought the Li stuff was plentiful, easy to get at, and easy to convert into a energy dense toxic batt pack, which by now should be driving down prices on a daily basis. I guess we were lied to.

So in grand scheme of tech, is it now supercap vs HFCEV ? I know Toyota is working on system where the 'gas' tank is just water, and the drive system is fuel-cell or HICE or HICE-hybrid.

The issue with supercap is the sudden release of energy, like when Li packs light up and cut vehicle in half. We don't have that problem if the fuel is a tank of water. The more energy dense and bigger the supercap gets, the more dangerous it becomes. The bigger the water tank gets, the heavier the vehicle is.

IMHO,..... batt pack of any kind for cars and trucks, is nothing more than CD just waiting to kill DAT. Already a dying fad, etc.

[SteveThackery]

So in grand scheme of tech, is it now supercap vs HFCEV ? I know Toyota is working on system where the 'gas' tank is just water, and the drive system is fuel-cell or HICE or HICE-hybrid.
<... >
The bigger the water tank gets, the heavier the vehicle is.

I'm confused. What is the water for? As a source of hydrogen? Where does the energy come from to hydrolise it?

[Electrodynamic]

There's actually quite a lot of publicly funded research in the EU (and Britain) into sodium ion capacitors and hybrids. Nordic Nano not part of it, but they likely used that as inspiration for their pitch.

So there is, but I thought the energy density was poor compared to even regular lithium ion, and so they aren't really a practical thing?

Around 1500mAh in a 18650 cell, with 3v average voltage.
It's not an energy density champion, but the price can drop very low with volume. I think they already going into electric cars in China. And it has other benefits.

I thought the Li stuff was plentiful, easy to get at, and easy to convert into a energy dense toxic batt pack, which by now should be driving down prices on a daily basis. I guess we were lied to.

So in grand scheme of tech, is it now supercap vs HFCEV ? I know Toyota is working on system where the 'gas' tank is just water, and the drive system is fuel-cell or HICE or HICE-hybrid.

The issue with supercap is the sudden release of energy, like when Li packs light up and cut vehicle in half. We don't have that problem if the fuel is a tank of water. The more energy dense and bigger the supercap gets, the more dangerous it becomes. The bigger the water tank gets, the heavier the vehicle is.

IMHO,..... batt pack of any kind for cars and trucks, is nothing more than CD just waiting to kill DAT. Already a dying fad, etc.

A tank of water running a fuel cell?. You do understand it takes "energy" to split the water into hydrogen for the fuel cell don't you?. Or is this one of those vehicles powered by water? .

Super capacitors are by far the best solution because they can be built from common materials like graphene from carbon and almost any conductor like copper or aluminum. Couple super capacitors with a brush-less Rare Earth-Free Electric Motor and it's game over for all the competition.

https://kittybnk.com/mahles-rare-earth-free-electric-motor-a-sustainable-innovation/

[Randy222]

A tank of water running a fuel cell?. You do understand it takes "energy" to split the water into hydrogen for the fuel cell don't you?. Or is this one of those vehicles powered by water? .

Super capacitors are by far the best solution because they can be built from common materials like graphene from carbon and almost any conductor like copper or aluminum. Couple super capacitors with a brush-less Rare Earth-Free Electric Motor and it's game over for all the competition.

https://kittybnk.com/mahles-rare-earth-free-electric-motor-a-sustainable-innovation/

Using the energy from water to split water for use, is rather simple. The pitfall, not unlike a ice-EV hybrid, you need a little energy (H or from batt) to get things started.  But yep, the system will split the water to get at H. There's no physics violations, you consume water (some of it) to keep the system running. When the water goes dry the system stops.

Some shocking math.
1gal of water can make 4707 litres of H, which is approx 422g worth
The Toyota Mirai goes 647km per 5.6kg H

I wave the magic math wand at it, that's about 30mi per 1gal of water.
A 20gal tank of water has in it 600mi worth of H, when the system used is the Mirai HFCEV.

BUT

With current tech, the use-to-make ratio is approx 1.58:1
1.58gal of water needed to split 1gal of water.
For every 2.58 H atoms coming out of electrolysis, 1.58 has to be fed back to the electrolysis process, and 1 part goes to the HFCEV propulsion system.

So, that means you need to consume 2.58gal water to go 30mi, thus a 20gal water tank can take vehicle approx 232mi.

Even with that dismal 1tank range, I am ok pulling over to fill up 20gal from a garden hose. Make tank 30-40gal, then you have great range.

BUT

HFCEV is only about 38% efficient currently. However, I already included that hit by using the Mirai system, it's range per kgH aleady includes the 38% efficiency factor.

Avg water gal cost in US (online stats) is 3c/10gal, or 0.3/gal.
20gal =232mi = 6 cent.
Crazy yet true.

H is the future, period.

btw, check my math.

The elephant though is, such vehicle will likely be costly up front, so the total cost (TCO/mi) over say 10yrs or 300kmi, is perhaps higher per mile than existing gasoline or EV, but build costs will come down over time. Recall the very first BluRay players, probably cost 10-20x more then vs now.

[tszaboo]

Using the energy from water to split water for use, is rather simple. The pitfall, not unlike a ice-EV hybrid, you need a little energy (H or from batt) to get things started.  But yep, the system will split the water to get at H. There's no physics violations, you consume water (some of it) to keep the system running. When the water goes dry the system stops.

Some shocking math.

This is not what's happening in a hydrogen fuel cell car, you are way off with your understanding of that technology.
Please look it up, and get a bit of extra understanding on it.

A tank of water running a fuel cell?. You do understand it takes "energy" to split the water into hydrogen for the fuel cell don't you?. Or is this one of those vehicles powered by water? .

Super capacitors are by far the best solution because they can be built from common materials like graphene from carbon and almost any conductor like copper or aluminum. Couple super capacitors with a brush-less Rare Earth-Free Electric Motor and it's game over for all the competition.

https://kittybnk.com/mahles-rare-earth-free-electric-motor-a-sustainable-innovation/

"wireless power transmission to energize its rotor"
Oh no they re-invented the asynchronous motor, 200 years after it was first made.

[shapirus]

Using the energy from water to split water for use, is rather simple.

Sure it is: raise water to a sufficient height, then pour it from there onto a wheel or turbine, which will drive an electric generator. Then use the electric energy it produces for electrolysis to split water into hydrogen and oxygen, job done.

[Randy222]

Using the energy from water to split water for use, is rather simple.

Sure it is: raise water to a sufficient height, then pour it from there onto a wheel or turbine, which will drive an electric generator. Then use the electric energy it produces for electrolysis to split water into hydrogen and oxygen, job done.

There's no need to lift the water. And we're not talking about gravitational potential.

Energy that is in water, just like joules that are trapped in gasoline.

 You only need to start the system, hence you need some stored H to run through HFC or HICE to get the electric end going. Perhaps the vehicle totes a small car batt too, just in case the H goes completely dry you can used the batt to get some H from electrolysis, then that H is used to "start" the system

No free lunch here, it consumes 1.58 gal to split 1gal. However, the eco side of the process is 100% clean.

The piece not talked about yet, how to make electrolysis speedy and more efficient. Duke Univ has been working on that problem.

[shapirus]

Energy that is in water, just like joules that are trapped in gasoline.

Yeah, but to release the joules you need to spend at least as much energy to split the water to produce H and O as you're going to get back when combining hydrogen and oxygen back together.

Water is the lowest-energy, stable combination of hydrogen and oxygen. You cannot extract any more energy from it, at least chemically (but you can in a fusion reactor).

Gasoline is different. It's unstable and still has chemical energy that can be released. When you burn gasoline, it produces energy plus a number of stable substances that (when fully burnt) can no longer release energy, just like hydrogen, when burnt, produces energy plus water, which can no longer burn.

Come on, are you trolling or something? This is middle school chemistry and physics and fundamental laws thereof.

You only need to start the system, hence you need some stored H to run through HFC or HICE to get the electric end going. Perhaps the vehicle totes a small car batt too, just in case the H goes completely dry you can used the batt to get some H from electrolysis, then that H is used to "start" the system

No free lunch here, it consumes 1.58 gal to split 1gal. However, the eco side of the process is 100% clean.

The piece not talked about yet, how to make electrolysis speedy and more efficient. Duke Univ has been working on that problem.

Nonsense. You always spend more energy on electrolysis that you can get back from burning hydrogen and making water again. That's it, there's no way around it.

[Randy222]

Yeah, but to release the joules you need to spend at least as much energy to split the water to produce H and O as you're going to get back when combining hydrogen and oxygen back together.

Water is the lowest-energy, stable combination of hydrogen and oxygen. You cannot extract any more energy from it, at least chemically (but you can in a fusion reactor).

Gasoline is different. It's unstable and still has chemical energy that can be released. When you burn gasoline, it produces energy plus a number of stable substances that (when fully burnt) can no longer release energy, just like hydrogen, when burnt, produces energy plus water, which can no longer burn.

Come on, are you trolling or something? This is middle school chemistry and physics and fundamental laws thereof.



Nonsense. You always spend more energy on electrolysis that you can get back from burning hydrogen and making water again. That's it, there's no way around it.

To extract means to get from. We get lots of energy out of gasoline when it burns.
We get useable potential energy in form of H by splitting water. We then consume (process) H to get energy out of it.

And yes, I already listed the math, it takes 1.58x more H to make 1H.

1.58H consumed to get back 1H.

As H is produced, 1.58H is sent back to electrolysis, the other 1H is sent to the propulsion system.

Heck, round it over to 2:1, that's a 3gal system, takes 2 to make 1.

For every 1gal split for propulsion, 2gal is consumed in splitting that 1gal. 30gal tank, 20gal used to convert 10gal for propulsion.

Edit: will stop here on H.
The supercap stuff is cool, has some applications, but it's dead tech for cars, truck, forklifts, etc.

[Bud]

Judging on the "charging demo" clip , their technology is a Resistor. This is the only technology the "demonstrated"  charging profile fits (no change in voltage and no change in current over the charging cycle).

But there are IC's for supercap charging that can do CC and CV modes. Having both I and V stuck on a # does not make sense though.

https://www.mouser.com/datasheet/2/256/MAX17701-1888136.pdf

No, that is just a constant current controller, it switches to constant voltage at the end of the charging cycle, they show this in the diagrams.

[SteveThackery]

There's no need to lift the water. And we're not talking about gravitational potential.

Energy that is in water, just like joules that are trapped in gasoline.

 You only need to start the system, hence you need some stored H to run through HFC or HICE to get the electric end going. Perhaps the vehicle totes a small car batt too, just in case the H goes completely dry you can used the batt to get some H from electrolysis, then that H is used to "start" the system

No free lunch here, it consumes 1.58 gal to split 1gal. However, the eco side of the process is 100% clean.

I'm struggling to understand this. But as far as I can tell, it is complete drivel from start to finish. The first thing to say is that there is no chemical energy in water.

Splitting water into H2 and O2 by electrolysis consumes more energy than even a 100% efficient hydrogen fuel cell can produce by consuming the liberated hydrogen. Why? Because electrolysis of water has a maximum theoretical efficiency of 83%, and a maximum practical efficiency of around 60%.

You made this really weird statement:

"... it consumes 1.58 gal to split 1gal"

What do you mean by "consumed"? Let me repeat:

It uses more hydrogen to "split" (electrolyse) water than is liberated by the electrolysis.

There is simply no way to "release" the energy that is in water, because there isn't any. Your claims are so ridiculous and brain-dead I can only assume they are a joke? If not, then you have an astonishing lack of understanding of basic science.

[Bud]

I think there is no reason for debating if we agree Donut's "charging demo" clip is s fake. If this was a fake, everything else is likely to be the same.
I have no idea why would they want this fake. Did not they realize engineers would be looking at it?

[SteveThackery]

For every 1gal split for propulsion, 2gal is consumed in splitting that 1gal. 30gal tank, 20gal used to convert 10gal for propulsion.

You seem to misunderstand. That 2 gallons of water does not have energy sitting in it ready to use for splitting the other 1 gallon. Electrolysis does not liberate energy, it consumes energy.

Let me ask you a simple question. If we can liberate energy from water in the way you suggest, why are we fucking around with digging gas and oil out of the ground? With solar panels and wind turbines?  Water is abundant - why aren't we just using that?

You know what? This conversation is so surreal I'm certain someone is either a moron or taking the piss.

[thm_w]

I think there is no reason for debating if we agree Donut's "charging demo" clip is s fake. If this was a fake, everything else is likely to be the same.

I would agree unless you can show some obvious screw up. The PSU says its always in CV mode which is odd, but it might be a quirk of that specific psu.. Normally a PSU would show CC when voltage setpoint is not reached, as the current is capped at 270A.

You can do frame-by-frame (, and .) the first voltage is 2.7V, 1ms later once power is on it jumps to 3.6V, then sits at 4V from 1s on.

Here is a smaller 100A li-ion capacitor where they charge it at 100A and you can see voltage is super linear in comparison: https://hal.science/hal-00373149v1/document donut is a bit similar to LCO cell curve, though even flatter.

[EEVblog]

I think there is no reason for debating if we agree Donut's "charging demo" clip is s fake. If this was a fake, everything else is likely to be the same.
I have no idea why would they want this fake. Did not they realize engineers would be looking at it?

That's the thing, I don't think it's "fake" as such.
I think the camera really is pointing at PSU screen and it's really delivering that, and the time is accurate etc.
It's what they leave out and don't show you that matters.
I think they simply have more cells in parallel off-camera, and they are just showing one small pouch cell. So everyone just assumes it's all going into that one cell, and ergo they aren't lying, you are just misled by your own assumption.

[rteodor]

That's the thing, I don't think it's "fake" as such.
I think the camera really is pointing at PSU screen and it's really delivering that, and the time is accurate etc.
It's what they leave out and don't show you that matters.

And, when the time is up they will most likely mull the specs in Eric Cartman's style.

[Siwastaja]

Water is the lowest-energy, stable combination of hydrogen and oxygen. You cannot extract any more energy from it, at least chemically (but you can in a fusion reactor).

Nonsense. I have a motor which produces 10kWh of energy out of a liter of water. It produces hydrogen and oxygen out of water, extracting 5kWh of energy, then it combines those back to water, producing another 5kWh of energy. I'm manufacturing this at abandoned warehouse, I'm already planning to build fences around it. You can already buy this. Just buy it for 40000€ from me and I'm going to send it to you in two months. Trust me bro, can't be scam, what would be the financial gain?

[AVGresponding]

I thought the Li stuff was plentiful, easy to get at, and easy to convert into a energy dense toxic batt pack, which by now should be driving down prices on a daily basis. I guess we were lied to.

Lithium is plentiful in the earth's crust, and indeed the oceans. It's the cobalt needed in the cathode, that is problematic.

[EEVblog]

Nonsense. I have a motor which produces 10kWh of energy out of a liter of water. It produces hydrogen and oxygen out of water, extracting 5kWh of energy, then it combines those back to water, producing another 5kWh of energy. I'm manufacturing this at abandoned warehouse, I'm already planning to build fences around it. You can already buy this. Just buy it for 40000€ from me and I'm going to send it to you in two months. Trust me bro, can't be scam, what would be the financial gain?

Don't answer that knock on your door. Run out the back and keep running.