Here's a photo of one of the first applications of the new Tesla 4680 structural battery:
For comparison, behind the cut away mock-up is a mock-up of the old 2170 cell design.
This is from the Berlin Gigafactory public tour. It looks like the battery box completely replaces the floor and is bolted into the cast and sheet metal body. Corrugated cooling channels appear to be placed between every other row of cells. Not shown are the buss bars and the bonding between the top cover/ floor and the top of the cells. There's a lot of DIY potential here, with the right vehicle, with the bolt-in design and structural member aspect of the battery box.
Cylindrical cells have a packing disadvantage - the hexagonal close packing density is about 90% in the middle of the field and worse at the edges, but the overall disadvantage is somewhat less than that because pouch and prismatic cells don't pack perfectly, either. The more limited size of practical cylindrical cells leads to higher interconnection cost and complexity, although perhaps no more relative volume.
The limitation of folding sheet material into pouch or cylindrical cell formats has been mentioned, but bend radius is an issue for cylindrical cells, too, as the roll approaches the axis of the cylinder... and the entire roll is bent. That's roughly a wash.
Cylindrical cells in metal cans have an advantage, of not needing other structural features to contain or accommodate expansion and contraction of the cell materials because they are contained relatively rigidly in the can.
Obviously both pouch and cylindrical formats are viable choices.
Volvo and Stellantis are mentioned in the GM article as changing over to cylindrical cells. BMW apparently is also making the switch to cells similar to the 4680:
It seems to me that something may be going on with LG.....either an aquisition or financial trouble are my top two guesses.
<takes tinfoil hat off>
The Bolt EV battery replacements have allegedly slowed to a trickle. My 3 year old 2020 has yet to have the recall done. Not that I don't mind a new battery a few thousand more miles into the odometer, but LG has to remain viable.
Is Tesla still considering using the elongated prismatic(if that is what they area) blade battery cells? These cells in a pack, may have some structural potential and have obviously higher volume fill potential. Any new info?
From the recent Tesla Investor Day, more details were filled out about the improvements and benefits of the 4680 cells in Monro's recent video starting at around ~11:20 :
Tesla has been using CATL's LFP batteries in Chinese production; those are apparently prismatic cells. There were many media reports last summer of Tesla deciding to use BYD's LFP "Blade" cells in Shanghai and even Berlin; blade cells are indeed very long and thin prismatics.
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