Testing of high energy density capacitors

The U. S. Army Research Lab (ARL) is investigating the capabilities of high energy density capacitors at narrow pulse widths from two different manufacturers for high current pulsed power applications. Breakthroughs in this technology would allow smaller capacitor storage to be possible while retaining the same capabilities. The discharge pulse widths of the test shots were between thirteen and fourteen microseconds. These pulse widths were taken from the full wave half maximum pulse width (FWHM). Both capacitors are rated for 12.5 kJ of energy and are 250 μF but have different volumes. The General Atomics Capacitors (GA-ESI 38982, 38994) have a total energy density of 1.3 J/cc while the manufacturer B’s capacitor has an energy density of 0.64 J/cc. Both General Atomics’ and manufacturer B’s capacitors are polypropylene metallized film capacitors. While energy density is a major concern for our tests; attributes such as peak current, rise time, and high voltage lifetime were other factors to be considered. ARL is collaborating directly with General Atomics to help provide input and data in order to improve all properties of their capacitors.