Manufacturing of Electric Double-layer Capacitors using Carbon Nanocoils and Evaluation of their Specific Capacitance at a High Scan Rate

Abstract

Electric double-layer capacitors (EDLCs) have problems that the specific capacitance decreases by increasing scan rate. In this study, activated carbon (AC) and various carbon nanomaterials are compared by their specific capacitances. Carbon nanomaterials used were arc-black (AcB) which was prepared by an arc discharge and carbon nanocoil (CNC) which was prepared by a chemical vapor deposition. CNC and AcB showed lower charge transfer resistance than AC in the measurement of electrochemical impedance spectroscopy (EIS). This explains that the EDLCs composed of CNC and AcB kept their specific capacitance at a high scan rate.