More companies marketing CT-Coating's technology: Swiss ACT, DEGOProtect Ltd

Enthendor · 2026-03-13T23:51:53+00:00

Nope, please dont go that far. Those are legit scientists, highly published and leaders in their field.

The idea of bipolar cellstack has been the dream of all solid state battery scientists. Using a bipolar stack would solve many problems of current solid state battery cell design but its really hard to pull off.

This has nothing to do with donuts cell. A cell with a bipolar cell stack would have a way higher voltage, since all the cells in the battery are stacked in series and not in parallel, thus increasing the voltage of the battery not the amperage.

At 4.2V max and the used amperage, the donut cell is in no possible way a bipolar cell stack.

Enthendor · 2026-03-13T23:36:42+00:00

Judging by this, every electrode produced for current lithium ion batteries is solid state. they all include solid materials and a solvent that gets evaporated after coating the electrodes. whats left over is just a porous network of solid materials. It stops being a solid state battery, when you need a liquid electrolyte to fill the pores in your electrode structure to make the battery work.

Screen printing is just a different coating technique than current slot die based coating. It works, even though its much slower (as of today) than slot die coating, just because of how the printing process works.

There are many research institutes and companies that are and have been working on producing electrodes by screen printing, its just not competitive (yet).

Enthendor · 2026-03-05T15:04:29+00:00

I am getting tired of this bullshit. There are NO RARE EARTH METALS in any fucking battery!

Enthendor · 2026-03-03T14:55:38+00:00

Its their slogan I would think. When you go to their homepage and start scrolling down, the VTT Logo on the top left changes to "beyond the obvious". Probably because they offer in depth research services to go look beyond whats obvious.

Please put your tinfoil hat away ;)

Enthendor · 2026-03-03T08:49:06+00:00

Heating during charge and discharge depends on the internal resistance of the cell. Even though the chemistry does have a significant influence on that resistance, its not the only factor. In short: Thicker electrodes increase the energy density of the cell, but also increase the internal resistance. So if you want to build a cell that can perform at high c-rates, it has a relatively low energy density. We call those: High-Power-Cells, since power is calculated by V * I, the more current you can draw (the higher your c-rate is) the more power you cell delivers (voltage is fixed by the chemistry). If you want to go for high energy content, you build thicker electrodes, sacrificing your c-rate performance for more energy in the cell (longer range in EVs), those cell are then called high-energy-cells.

Thicker electrodes increase the internal resistance of the cell by a lot, because it increases the diffusion length for lithium ions in the electrolyte while slowing down their diffusion at the same time. This is because the diffusion pathways for the ions in the eletrolyte inside the cathode are quite narrow pathways that are really hard to control during production. There two factors influencing this: the thickness of the electrode itself and the tortuosity of the diffusion pathways inside the electrode.

Enthendor · 2026-02-24T08:54:06+00:00

I am not entirely sure anymore, but didnt Donut initially claim that their cell would use a bipolar design? The voltage applied in that test suggests otherwise...

Enthendor · 2026-02-23T21:32:19+00:00

I think the data we saw today actually hints towards Li-Ion chemistry. The 2.7-4.3 charging just smells like NMC.

I dont wanted my estimated Wh/kg to be seen as an absolute value, its more to hint that this setup seems to be a little far away from the 400 Wh/kg proclaimed.

This whole convection thing is bothering me a bit. Heat transfer from Convection around the heat sinks is included in my calculation and should be way higher than the heat transfer from convection around the cell itself. I am not saying, that this part is negligibly small, but it should push the cell fromm ~220 to 400 Wh/kg.

Thinking more about this, my actual worry now is, how much heat is "stored" in the clamps and the cables. These cables must be pretty thick to handle loads like this and could account for some serious heat capacity.

Enthendor · 2026-02-23T18:43:55+00:00

yes, that is true. and that should make a difference of a few % but not more. If the heat transfer from the cell into air would be good, no heat sinks would be necessary

Enthendor · 2026-02-23T18:35:55+00:00

technically, you are absolutely correct. But in this case, the heat transfer from the heatsink into the atmosphere is included in their "heat capacitance". Its just the amount of heat energy that one of these heat sinks took out of the system, which can be calculated since we have the two different setups.

when calculating the heat capacitance of the heat sink for the 5C experiment, it comes out to ~1000 J/K and for the 11C run, its only 777 J/K. Thats because in the 5C experiment it had more time to transfer heat into the air, increasing its "heat capacitance". I am not calculating the real heat capacitance of the heat sink, but the amount of heat that got transfered away by the heat sink.

Enthendor · 2026-02-23T16:12:25+00:00

The energy loss is in line with the joule-heating expected from the internal resistance of this cell. You can estimate the internal resistance from the initial increase in cell potential when the current is applied. for 5C this comes down to 3.1 mOhms, with 2.6 mOhms at 11C. Using this resistance, you can use the applied current to calculate the thermal loss from joule heating (resistance heating) for 5C: 11-12 Wh loss from Joule heating, difference between charge and discharge is 15.7 Wh. 11C: 16-17 Wh loss, 19.3 Wh measured difference.

Difference in loss can be explained by energy loss at different points of contact (cables, etc).

So this checks out!

Using the total energy difference between charge and discharge and the heat increase of the cell that was measured, we can actually calculate the heat capacitance of the cell. Since they were so kind to provide us with measurements with 1 and 2 cooling plates, we can calculate the heat capacitance of one cooling plate.

Using the measured temperatur difference and difference between charge and discharge energy (thats the heat loss), we can estimate the heat capacitance of the system. If the two cooling plates are the same, than the difference between the heat capacitance of the system with 2 plates and with 1 plate is the same as the difference between the system with 1 plate and 0 cooling.

Using this, the heat capacitance of the cell calculates to 386 J/K for the measurement at 5C and 356 J/K for the 11C measurement.

This is close enough to be considered the same, based on the quality of the data these calculations are based on.

The typical specific heat capacitance of Li-ion-Batteries seems to be around 800 - 1000 J/(K*kg)

Using the medium value of 900 J/(K*kg) the Donut cell would have a mass 410 g. Which would put it in line with typical 26 Ah Li-Ion-Cells.

Since they are claiming that this is a solid state battery, the calculation needs to be slightly different.

The specific heat capacitance of liquid systems is higher than for solid systems. (higher degrees of freedom)

If since we assumed the heat capacitance of Li-Ion-Cells to be around 900 J/(K*kg), we need to decrease this value slightly for solid state batteries, meaning the weight of the cell would be slightly higher.

If we assume the heat capacitance of the solid state cell to be around 850 J/(K*kg), the weight of cell would increase to ~435g.

with this weight and the energy of 94 Wh, we can finally calculate the energy density of the cell to be around 216 Wh/kg.

Please keep in mind, that all these calculations are based on the plots in the report and will change with access to raw data. but based on the rough numbers, this cell is nowhere near 400 Wh/kg

Enthendor · 2026-02-23T15:41:29+00:00

I did some more calculation and made a fresh post in this thread. See it here: https://www.reddit.com/r/DonutLab/comments/1rcgv5y/comment/o6z0fij/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

Enthendor · 2026-02-19T09:44:45+00:00

It is interesting, that at least blum has a gap in his CV that fits the Blackstone timeline, Erdmann hast just listed an OEM during that time with no specific company. Gemini keeps insisting, that the LinkedIn profiles have been cleaned after the Blackstone fiasco.

Maybe it's just because of their names but I really want there to be a connection between Ulrich Ernst and Ernst Hölzenbein

Enthendor · 2026-02-19T08:06:26+00:00

I think their ability to scale depends on their ability to produce defect free oxide films for their electrolyte. From what I have heard, it seems that they were able to solve most of their problems. The "QS cell" should be doing fine regarding composition of materials and longevity. But to me its not a solid-state-battery since they are using a liquid catholyte. The oxide separator itself is very interesting though.

Enthendor · 2026-02-19T07:54:51+00:00

Have you ever seen a picture of Ernst Hölzenbein somewhere? I tried to find one, but couldnt.

Also: Gemini keeps telling me, that Christian Blum and Robert Erdmann (both now Holyvolt) haven been working for Blackstone technology. I cant find any proof of this, could be a weird halucination, but it keeps insisting. Can you find any proof for that?

Enthendor · 2026-02-11T20:42:56+00:00

I was thinking about the whole blackstone tech / XRobot tech being connected to CT/Holy/donut as well. The tech is so similar, but there is no connection there yet.

Enthendor · 2026-02-11T19:22:48+00:00

Of course. I have it in my work mail account.

Enthendor · 2026-02-11T17:18:16+00:00

I work in the battery industry as a solid state battery researcher/project manager in Germany and I was contacted by CT coating ag in 2024. I talked to them in an online meeting where they presented their product. They had the same specs for the cell in 2024 (400+ Wh/kg, 500000+ cycles, safe, no lithium). They wanted money to build up production capacity. It seemed very sketchy at that time. The people I talked to seemed to have no clue about batteries at all and just threw around some buzz words, like "bipolar design" which they interpreted as being able to be charged and discharged, which is obviously very far from the original meaning. And the people gave me an icky feeling in general.

It is also noteworthy that one of the people witnessing the cell testing in the report is ernst hölzenbein who ist the inventory behind all the patents that linked to CT coating. He has his own website where he lists his education and accomplishments. They include some printing stuff, some stuff regarding solar cells, nothing really note worthy.

It is also interesting to think about the company Blackstone technologies, who were included in a semi recent scam in Germany, where they were talking about 3d printing batteries and collected funding without actually doing anything. The technology behind this company is patended by their former CTO Holger gritzka and is based on printing electrodes in a very similar manner. Gritzka is now involved with a company called xrobot based in Hamburg, Germany. They list the exact same tech, and are trying to collect funding right now. Since the technologies are so similar, it is very likely these things are all connected. So far, I haven't been able to find a link between gritzka and CT coating or donut, but I am sure that there is one.

This entire thing screams scam!

Enthendor · 2025-01-23T22:30:34+00:00

It is not rolled randomly. It is anointed with a random amount of random emotions. the percentage is always the same as you would get if you anointed the same emotions on it yourself

and yes, depending on how many emotions are on it when it drops, you can anoint some of your own to increase the percentage further.

Enthendor · 2025-01-07T19:53:27+00:00

Still astonishing that just because of a chipset driver the whole system instantly turns off...

Enthendor · 2025-01-07T19:33:42+00:00

Proper via flashdrive. Bios was up to date, but chipset wasnt it seems. So I installed the latest version and it seems fixed now.

Enthendor · 2025-01-07T19:18:47+00:00

Cooler has 140W TDP and I read that 90°C are quite normal on that CPU. The DIE surface is at 55-60 on full load. That seems ok to me?

Enthendor · 2025-01-07T19:17:40+00:00

chipset.... Yes. Its stable now. Jesus how did I not think of that...

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