The larger cell would have technical challenges that Tesla patents have already addressed.

Tesla Battery Day is only a day away, making the expectations about its surprises get even higher. We already know that Tesla will probably present its “Biscuit Tin” cell, a much larger one than it currently uses. That poses significant challenges, such as cooling. Jordan Giesige, from the YouTube channel The Limiting Factor, offers us the best overview of them so far, as well as of the solutions that may have made the new battery possible.

The first help the video gives us is trying to define the precise dimension of the new cell. The Tesla “Biscuit Tin” would have a minimum of 40 mm of diameter and 70 mm of length, which already makes it much larger than the 2170 cells Tesla currently uses (21 mm of diameter and 70 mm of length). Still, we have reasons to believe it is even larger.

The first images that presented the new cell also came with the “SFX054” inscription, which could mean it has a diameter of 54 mm. Sandy Munro said there were rumors that the new Tesla-made batteries would be thicker than 50 mm, which gives this hypothesis more substance. 

If that was the case, and considering the battery proportions, some have guessed that it will be 98 mm long, but the video goes way beyond what we can see: it discusses why no one else has tried to do such a large battery for electric cars so far.

One aspect the video does not address is the investments current battery manufacturers have made into producing the cells it currently supplies. Like legacy automakers, they don’t want to lose that money by creating something that will make their current products obsolete. It would have to come from a company willing to disrupt that. You already know which company is that.

The video talks about the technical reasons for that, and the most important one is cooling. Larger batteries would be much more challenging to manage if they were just larger versions of the current ones. They needed new technologies to be feasible. The video suggests they are the Maxwell’s Dry Battery Electrode Technology, the tabless electrode, and a new cooling system. Understand how they perfectly match together with Giesige’s video.

Source: The Limiting Factor