Electrochemical capacitor performance of 2-(trimethylsilyloxy)ethyl methacrylate-derived highly mesoporous carbon nanofiber composite containing MnO2

Abstract

2-(Trimethylsilyloxy)ethyl methacrylate (SMA)-derived mesoporous carbon nanofiber composite containing MnO2 (Si-Mn-CNF) is fabricated by electrospinning method and found to be a very promising candidate for supercapacitor electrodes. Si-Mn-CNF possesses a large surface area of 707m2g−1, high pore volume of 2.35cm3g−1, and high mesopore fraction of 65%. Herein, SMA is used as an activating agent to develop the mesoporous structure by the thermal decomposition of SMA without activation process. As a result, Si-Mn-CNF exhibits a high specific capacitance of 200 Fg−1 at a discharge current density of 1 mAcm−2 and energy density of 23.72Whkg−1 at a power density of 400Wkg−1 in 6M KOH aqueous electrolyte, due to the pseudocapacitive character associated with the surface redox-type reactions of the MnO2 nanoparticles (NPs). Furthermore, the Si-Mn-CNF electrode retains a specific capacitance of over 85% of the initial value at a discharge current density of 20mAcm−2 compared with only 40% for Mn-CNF without using SMA, due to the rapid diffusion of electrolyte ions and the decrease of resistive characteristics through the developed mesoporous structures. Therefore, Si-Mn-CNF with high mesoporosity induced by SMA exhibits excellent electrochemical performance in terms of high specific capacitance and energy density, and excellent capacitance retention.