The overall charge that can be held in a supercapacitor is limited by the kind of electrolyte and electrode surface area as compared to a battery's entire electrode and total active mass. Supercapacitors operate similarly to traditional capacitors. Supercapacitors have increased capacitance (F/g, F/cm 2 ) because their electrodes have a large surface area and new electrode materials, and electrolytes can boost supercapacitors' energy density. There are three types of supercapacitorselectrochemical double-layer capacitors (EDLCs), pseudocapacitors, and hybrid capacitorsdepending on the charge storage mechanism . The electrochemical double-layer capacitors, sometimes referred to as EDLCs, are devices that electrostatically store charge at the junction of an electrode and electrolyte, resulting in positive and negative ions' double layers. In pseudo capacitance, energy is stored by the redox process, but in EDLCs, energy is stored through ions adsorption between electrode and electrolyte. Highly porous materials are used in the fabrication of electrodes for EDL capacitors. The Faradic reaction at the electrode-electrolyte interface is the source of the energy storage mechanism in pseudocapacitors (PCs) (Figure .2) .