Once all the required electrode processes are performed for both positive and negative electrodes, the process of winding is evaluated. During the winding process, the stack of the cell components (Figure ) is wound on a mandrel to form a jelly roll. The virtual pilot line makes cylindrical cells with dimensions diameter = 18 mm and height = 65 mm (18650 format). The positive and negative electrodes are winded on a rod called a mandrel (diameter = 2 mm). To accommodate the cap of the cell and the swelling of the jelly roll during electrolyte filling and cycling, the volume of the jelly roll should be less than the volume of the cell. So, the maximum volume that can be occupied by the jelly roll is,