Supercapacitors, also known as EDLCs (electric double layer capacitors), differ from ordinary capacitors in that they can store large amounts of energy. Basic capacitors are usually composed of two metal plates separated by an insulator (such as air or plastic film). During charging, electrons accumulate on one conductor and leave the other conductor. One side gains a negative charge while the other side establishes a positive charge. The insulator interferes with the natural pulling of negative charges to positive charges, and this tension creates an electric field. Once electrons are given a path to the other side, a discharge occurs.

The supercapacitor also contains two metal plates coated only with a porous material called activated carbon. They are immersed in an electrolyte made of positive ions and negative ions dissolved in a solvent. One board is positive and the other board is negative. During charging, ions from the electrolyte accumulate on the surface of each carbon-coated plate. Supercapacitors also store energy in an electric field formed between two oppositely charged particles, only they have an electrolyte, in which an equal number of positive and negative ions are evenly dispersed. Therefore, during charging, each electrode eventually has two layers of charge coating (electric double layer).