There has been some buzz about cylindrical versus prismatic cells. Having returned from Costco with case of Kleenex and already having a case of toilet paper, here is a model: cylindrical - tightly wrapped, high volume efficiency but empty space around the outside. Those empty spaces around the circumference can fill with coolant to manage temperature. Thermal gradient will be outside to center as will be any strain (small displacements) between layers. Length of individual cell is the maximum. prismatic - loosely stacked to handle individual sheet expansion/contraction, the highest volume efficiency but challenges getting heating and cooling to the interior. Badly done, the cooling and heating parallel to the edges of the stack can lead to strain between layers. If done normal to the layers, less bad. Multiple sheets become multiple, small parts that have to be assembled. So if you go to a store and they are out of Kleenex, toilet paper can handle both ends. But Kleenex, even a group of sheets, is not so useful at the other end. Bob Wilson
Area: Kleenex box: 20.8 cm * 21.3 cm = 443.04 cm{2} Charmin roll: 15.9 m{2} / 6 = 2.65 m{2} = 26,500 cm{2} Bob Wilson
