Frequency and temperature dependent electrochemical characteristics of carbon-based electrodes made of commercialized activated carbon, graphene and single-walled carbon nanotube
By Kang, Jinhee; Atashin, Sanam; Jayaram, Shesha H.; Wen, John Z.
Published in Carbon
2017
Abstract
Abstract Electrochemical double-layer capacitors, consisted of electrodes made of commercialized activated carbon (AC), graphene, and single-walled carbon nanotube (SWCNT) are fabricated and investigated, in order to reveal the dependency of their performance on charging/discharging frequency and operating temperature. Their electrochemical properties are quantified by means of cyclic voltammetry, constant current charge/discharge and electrochemical impedance spectroscopy. Through varying the applied frequency and operating temperature, correlations are identified between the capacitive and resistive behaviors of these electrodes and their representative porous structures including morphology, surface area, and pore size distribution (PSD). It is observed that the graphene and {SWCNT} electrodes, possessing larger meso-pores with a wide PSD, show better capacitive stabilities and shorter current response periods under high-frequency operations. They however exhibit a large variation of internal resistance over the operating temperature range of ?30