A typical supercapacitor consists of three essential components, namely the electrodes, the electrolyte, and the separator. The overall performance of supercapacitors is determined by the physical properties of both the electrode and the electrolyte materials. Nevertheless, the electrode is one of the most important components for charge storage/delivery, and plays a crucial role in determining the energy and power densities of a supercapacitor. The electrochemical performance of a supercapaictor can be characterized by cyclic voltammetry and galvanostatic charge–discharge measurements 1, 2, 3, 4. The capacitance (C) is determined from the constant current discharge curves according to Eqn 1: