The specifics of ultracapacitor construction are dependent on the manufacturer and the intended application. The materials may also differ slightly between manufacturers or due to specific application requirements. The commonality among all ultracapacitors is that they consist of a positive electrode, a negative electrode, a separator between these two electrodes, and an electrolyte filling the porosities of the two electrodes and separators.
Internal Cell Construction
Most manufacturers have adopted a cylindrical construction method for their ultracapacitors; however, there are still products on the market that use a prismatic design. Tecate's products use a cylindrical construction method. The cells are constructed from activated carbon particles, which are mixed with a binder and then deposited on aluminum foil. In this method, as shown in the following figure, the electrodes are wound into a jellyroll configuration very similar to an aluminum electrolytic capacitor. The electrodes have foil extensions that are then welded to the terminals to enable a current path to the outside of the capacitor.
External Cell Construction