Prismatic cells are still rolled as far as I’m aware, and from the few videos I’ve seen. They just don’t start with round core, they start with a different shape, such as a flat one for rectangular cells like in cell phones or Apple laptops.
Apple hit a trifecta when they started making their own batteries. The MacBook where they introduced them got twice the battery life. The new OSX version had better battery management. The prismatic, unpackaged cells occupied 30% more volume within the case, because they dropped the packaging, the round cells, and used a tiny motherboard. And finally the chemistry of the new cells increased the watt hours per cubic centimeter by 30%.
But the difference between a laptop and a car is that the laptop batteries were maybe 3/8” thick. Plenty of top and bottom surface area to dissipate heat. Or so they thought (lots of swelling batteries in those models).
If you wrapped the battery around a thin trapezoid, or a very thin parallelogram, I think you get that truncated cuboid shape once you have laid up a half dozen layers or so, because of the way the radius of the corners builds up with each wrap.
Apple hit a trifecta when they started making their own batteries. The MacBook where they introduced them got twice the battery life. The new OSX version had better battery management. The prismatic, unpackaged cells occupied 30% more volume within the case, because they dropped the packaging, the round cells, and used a tiny motherboard. And finally the chemistry of the new cells increased the watt hours per cubic centimeter by 30%.
But the difference between a laptop and a car is that the laptop batteries were maybe 3/8” thick. Plenty of top and bottom surface area to dissipate heat. Or so they thought (lots of swelling batteries in those models).
If you wrapped the battery around a thin trapezoid, or a very thin parallelogram, I think you get that truncated cuboid shape once you have laid up a half dozen layers or so, because of the way the radius of the corners builds up with each wrap.