Jelly roll design refers to the construction used in cell manufacturing, where the anode, separator, and cathode are either wound together or stacked on top of each other. In wound designs, the long strips of anode and cathode, separated by separator material are rolled tightly to form a cylindrical or flat spiral structure. The ends of the roll are then connected to the external terminals, with tabs welded to the current collectors. These jelly roll designs allows a large surface area of electrodes to be packed efficiently into a cell. Stacked jellyrolls are generally constructed by placing alternating layers of anode and cathode punched electrodes between layers of separator as the separator is z-folded.
NOVONIX studies jelly roll designs primarily in the context of optimizing performance and safety. NOVONIX tests different separator materials or thicknesses in a jelly roll format to see how it affects performance, like internal resistance or cycle life, and cell safety. Additionally, when experimenting with new electrode materials, they ensure that those materials can be processed into the long, flexible strips needed for wound designs without cracking and to ensure those materials can be punched without flaking for stacked designs. By understanding the nuances of the jelly roll design, NOVONIX supports its clients in making cells that are robust, high-performing, and safe.
