Electric Double Layered Capacitors, known as “Gold Capacitors”, offer the highest volumetric efficiency of all capacitor technologies.
It is often compared to a secondary battery. Unlike batteries, the Gold Capacitor does not rely on a chemical reaction to produce electric current rather it is a storage cell that utilizes the absorption/release reaction of ions.
The Panasonic Gold Capacitor has no limit to the number of charge and discharge cycles it can sustain, and does not need a charging circuit. Repeated rapid charge and discharge cycles are also acceptable.

More information: Wikipedia