Flat cells are great if you're trying to build a flat product, where z space is much more critical than x and y. However, flat cells have an unfavorable effect

Flat cells are great if you're trying to build a flat product, where z space is much more critical than x and y. However, flat cells have an unfavorable effect on specific capacity (both weight and volume) since you need two flat sheets to package the display top and bottom, sandwiching a relatively thin active cell, instead of a single cylindrical package wrapped around a larger volume.