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Description

A traditional capacitor stores energy in the electric field created by charge separation. The electric field normally exists in a dielectric which becomes polarised. The capacitance is proportional to the permittivity of the dielectric and the area of the plates, and inversely proportional to the separation distance of the plates.

There is no intervening dielectric material in a supercapacitor. Most of the potential is dropped across the double layers, not a dielectric. Supercapacitors have a much higher capacitance than traditional capacitors because of the large equivalent area of the plates and the small effective separation distance of the plates.