[redpoint5]

I just watched a 40 minute Gigafactory tour video and was surprised to see that the new Tesla will use 2170 cylindrical cells rather than prismatic.

Why is the advantage of cylindrical cells vs prismatic?

I would think they would cost more due to increased use of materials (smaller individual capacities and more material used in the case). The increased casing material would also increase weight. Finally, there would be a lot of empty space with all the voids left by the cylinders not being able to stack flush with each other, so the energy density would be reduced.

When I bought a 20 Ah LiFePO4 battery, the best price I could find was in prismatic cells, with cylindrical being a bit more expensive.

So, what's the advantage? Will prismatic cells die out, with cylindrical being the way of the future?