An ultracapacitor, EDLC (Electric Double Layer Capacitor) or Supercapacitor, is an electrical energy storage device that shows electrical characteristics different from those of batteries or traditional electrolytic capacitors. The electric energy is stored in the electric double layer from charge separation which is electrostatic force between an ionically conducting electrolyte and a conducting electrode. The ions displaced in forming the Double Layers are transferred between the electrodes by diffusion through the electrolyte. The capacitance is depend on the electrode material such as surface area, pore size and pore size distribution. The stored energy has electric chemical characteristics ,not include chemical reaction, which are high efficiency of charge and discharge and rapid speed of charge and discharge and long cycle life of charge and discharge.
