Manufacturing of Electric Double‐Layer Capacitors Using Carbon Nanocoils and Evaluation of their Specific Capacitances at a High Scan Rate

Abstract

SUMMARYElectric double‐layer capacitors (EDLCs) have problems that the specific capacitance decreases by increasing the scan rate. In this study, activated carbon (AC) and various carbon nanomaterials are compared by their specific capacitances. Carbon nanomaterials used in this study 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 the lower charge transfer resistance than AC in the measurement of electrochemical impedance spectroscopy (EIS). This is a reason that the EDLCs using CNC and AcB kept their specific capacitance almost the same even at a high scan rate.