Tesla 4680 tabless battery

whatever

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Jun 3, 2010
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My thoughts on what it is:
first pic shows top and bottom are aluminium and copper, heat transfer to top and bottom without going over the plastic separator between copper/aluminium, basically heat goes to the ends.
so basically electrical path is same length as heat transfer path ( that is the change)
tabless.jpg
picture showing copper bottom part, shows that the copper extends past end of plastic separator and is folded over ( same happens at top where aluminium is folded over). Laser cuts make it easier to fold over the copper/aluminium so it lays flat.
thats it folks, thats all.
copper folds.jpg
 
I've just gone over the patent for tabless battery and another look at the video, below is a grab from the video, which is rather interesting, it is from new cell plant near to broadcast, it shows large cell being wound, note there is no laser cutting of the ends.
I actually suspect you dont even need to laser cut the ends then fold them, have a look at the copper and aluminium extensions,
I'm quite convinced you could just put the end caps straight onto those ends without folding them over at all and get just as good connection, the laser stuff might be a furphy to put off competitors, I dont think its necessary at all, way over complicated.
here is the video grab from video above I've annotated it:
video grab.jpg
 
ok hope that makes sense, anyhow here is some annotations I've done on the patent, lots of pics most should be self evident, but will save you guys having to read the patent. I think the laser cut ends and folding is not necessary at all.
here we go:
shows standard cell with one tab
fig1.jpg

below shows sheets, old and new style
bottom shows coated metal area/insulating strip and bare metal.
the insulating strip and bare metal are the bits that get folded over
(laser cut first in teslas battery video to give nice flat surface when folded over for battery
cap to sit onto)
fig2.jpg

below just shows making enough roll for 3 cells in one go
fig3a.jpg

diagram below is most confusing one, but it just shows
the ends being bent over in bottom of the can ( the laser cut bits)
I honestly dont think they will have to do this, it will work without doing it!!
its a red-herring I tells ya
fig6a.jpg


this one shows same idea as laser cut, so ends can be folded over
fig6d.jpg

there are 4 different end caps shown, here only showing one of them, plan and cross sectional view
fig10b and 11b.jpg
 
slight edit on the video grab, those spiral wound ends, one copper and one aluminium, I"m really convinced you could just push
end caps directly onto them, perhaps the outer portion of the end cap could be slightly angled to push the spiral wound
ends together a bit more tightly.
like this:
end caps.jpg

original pic with some writing to show the nice solid-ish copper and aluminium ends

video grab.jpg
 
one thing not mentioned as yet, that heating probably mainly occurs on one electrode preferentially , suspect the copper might
have more heat being electron source during discharge ( correct me if i"m wrong), charging is at lower amps and aluminium sheet will be heat source but not as significant as copper.
Patent doesn't show any difference between top and bottom electrode, but well could be as patent not likely to be same as when the cells get produced in real world.
 
"...the positive Cathode end uses an aluminum foil collector, and the negative Anode end uses a copper foil collector. The electrochemical “reasons” can be found here..."

https://www.electricbike.com/inside-18650-cell/

The copper collector is connected to the negative shell of an 18650 cell, and Tesla's cell-cooling system definitely pulls heat from the shell.

46mm x 80mm is...1.8 inches diameter, by 3.15 inches long.

The PR blurb suggests that the capacity is roughly 25-Ah with very high amps available...
 
thanks spinningmagnets, went through that link, some very nice pics and info you have put together, slight issue you say it has information on electrochemical reasons, there is a link in your article called "The electrochemical “reasons” can be found here.", its a link to a researchgate question from a reader with answers from internet users ( some credible some not), probably not best link to find out about electrochemicals of cells. I cant remember which but the tesla cells dont have both ptc and cid, I forget which one.
I was under the impression it was the aluminium that makes contact with the outer aluminium shell ( I could be wrong).

Here is another possible way to wind the cell to get a nice solid contact mass at the ends of the cells:
suitable thickness insulating layer/copper/aluminium layers would be required, cell would be a little heavier than tesla laser cut idea,
but would a very nice thermal mass at ends of the cells, which would be nice and solid ( spiral wound but act like a solid mass).
Numbers 1 and 2 show additional roll of copper aluminium to fill in spaces between end rolls, instead of fold over the ends after laser cutting. The width of the additional foil could probably be very narrow ( a few mm) or wider to make a bigger heatsink.

video grab.jpg

This is just one idea on how it could be done, no doubt telsa has brainstormed many different ways to do it, I can see how the method they came up with would be very fast with minimal change to production line, but there are many ways it could be done to achieve similar outcome.
Another method might be to use copper wire to fill in the end gaps in same manner as above.
 
heres another way of looking at it:
light blue vertical lines=insulation
red= copper
orange= copper
grey ( thin/vertical lines x2)=aluminium
For simplicity only copper end shown, you would effectively have a copper solid mass ( red/orange lines), that would act
as heatsink and electrical contact ( I've just filled in with grey above that......but you get the idea)
alternative roll.jpg



Another way to roll this would be:
video grab mod.jpg

In this method 3 and 4 are suitable thickness and width strips of copper and aluminium added to the edge of the foils as shown
( maybe need ultrasonic welds to hold in place?). But I think it would be comparable to laser cut/fold method in simplicity and
speed of rolling wouldn't be effected. Probably a simpler method than laser cut/fold.
 
heres a company video of CAT-L production line, its look damn fast, until you notice the workers are all speed up, the film is all sped up, leads me to wonder if telsa video of rolling electrodes together was actual speed or not. Did seem awfully fast.
https://www.youtube.com/watch?v=-DReeqKQSJ4
 
There are now significant hints that suggest all of the cooling will take place along the bottoms of the cells, and the current will be drawn from the top.

With the cells in a honeycomb arrangement, there is a small air gap that provides plenty of space for a short strip to connect the bottom of the cell to the electrical connection grid on top.

I can only assume that this arrangement keeps the electrical grid away from a puncture resulting from a Tesla running over some road debris, which has happened at least once...
 
spinningmagnets said:
With the cells in a honeycomb arrangement, there is a small air gap that provides plenty of space for a short strip to connect the bottom of the cell to the electrical connection grid on top.
Why do you think a “strip” is needed to the bottom of the cell ?
The cell can shell is the -ve connection ,,,all the ay up to the top lip . They could easily connect directly to that top edge of the cell.
 
The shells are typically steel, plated with nickel. The Tesla battery day details specified that these cells will be a structural member (Munro and associates) so I would be surprised if the shells were anything other than steel. These 4680 cells have been estimated to have roughly 25-Ah in each cell (not verified yet), and I suspect each one is capable of 50A or more...

Clearly the metal shells would conduct electricity, but I would not choose to run 50A through a steel conductor. This is just a guess, it's physically possible that Tesla will have a negative bus on the bottoms of the cells along with the cooling apparatus.

Edit: its quite possible that the shells are aluminum and are also used as a conductor.
 
spinningmagnets said:
Clearly the metal shells would conduct electricity, but I would not choose to run 50A through a steel conductor. This is just a guess, it's physically possible that Tesla will have a negative bus on the bottoms of the cells along with the cooling apparatus.
For sure, as we all know from assembling our small Ebike packs, there are many things to consider . so on a commercial EV scale, the thought and design factors are enormous, so it will be interesting to see how this is all put together ultimately.
 
This guy explains new Tesla battery properties, in the process peeling away Tesla's marketing spin.
I like his videos when it comes to detailed electrical engineering analysis.
Dave has been around now for over 10 years. I used to follow his online blog and EE forums.
https://www.youtube.com/watch?v=hbPKE62aM0U

[youtube]hbPKE62aM0U[youtube]
 
So, it is now being reported that it will be Panasonic who will actually manufacture these cells, not Tesla .? :?
Also LG will likely manufacture the cell as well !
...Panasonic is working on the development of a new battery cell for Tesla, based on the new 4680 format presented by Tesla at ‘Battery Day’. The South Korean battery company LG Chem, who similarly supplies Tesla, is also developing a new round cell that is very similar to the key data of the new Tesla cells.

“We started working on it immediately after Tesla’s Battery Day (in September) and are also preparing to set up a prototype production line in parallel,” explained Panasonic CFO Hirokazu Umeda when announcing the battery manufacturer’s latest business figures. “We have considerable know-how for that battery.”

The relationship between Tesla and Panasonic seems to have improved recently. In the first quarter, the Gigafactory 1 in Nevada operated by the two companies was profitable for the first time. This is where the 2170 round cells for the Model 3 and Model Y are manufactured from US production. As a result, Tesla and Panasonic agreed on a new three-year contract for Gigafactory 1 in June, and in July it was announced that Panasonic had again promised Tesla a version of the 2170 cell without cobalt in the cathode and with higher energy density.

Umeda also said that the company had decided to open an additional production line at its Nevada plant next year, increasing the total capacity of the plant by about 10 per cent to 38 to 39 GWh per year by around 2022. Exactly these figures had already been mentioned in an article in the Japanese business magazine Nikkei in August, but Umeda now officially confirmed the plans......
https://www.electrive.com/2020/10/31/panasonic-to-develop-new-4680-battery-cell-for-tesla/
 
Warren said:
Not for Tesla
https://insideevs.com/news/497176/bak-battery-unveils-first-4680-cells-china/

i will believe that these things are actually good when they can make a fuckton of them for less money. or even put one on aliexpress for me to buy.

i dont belive for a second that these cells will be comparable to tesla's chemistry, durabillty or reliabillty unless i have tested them and cracked a couple open.
 
flippy said:
i dont belive for a second that these cells will be comparable to tesla's chemistry, durabillty or reliabillty unless i have tested them and cracked a couple open.

Me too, they will be probably better than Tesla`s original production...
 
Pajda said:
Me too, they will be probably better than Tesla`s original production...

i am sure they can make a lab produced cell that is better then tesla's mass produced version. but i am not paying 5000 bucks for a single cell.
 
I'm sure some one has modeled the heat flow but the patent is more basic than that. By tapping the battery from the side they have shortened the electrical path thus reducing the internal resistance. Also the electrodes are larger so they can handle more current. This can be applied to other chemistries. Already NiMh D batteries have an internal resistance of .01 ohms. With the new technology we could have a D battery that charges in 5 minutes. This bridges the gap between batteries and super capacitors. All I want is a system that can capture brake energy.
 
Sandy Munro got a look at the new cells at the Texas party the other day: https://twitter.com/live_munro/status/1512215223268216833

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