Electrochemical performance of a coaxial fiber-shaped asymmetric supercapacitor based on nanostructured MnO2/CNT-web paper and Fe2O3/carbon fiber electrodes

The fiber-shaped supercapacitor is a promising energy storage device in wearable and portable electronics because of its high flexibility, small size, and light weight. However, most of the reported fiber-shaped supercapacitors have exhibited low capacitance and energy density due to the limited surface area between the two fiber electrodes and operating voltage range. Herein, we successfully developed a coaxial fiber-shaped asymmetric supercapacitor (CFASC) made from MnO2/CNT-web paper as a cathode coupled with Fe2O3/carbon fiber as an anode with a high operating voltage of 2.2 V. The prepared CFASC device showed a high volumetric energy density of 0.43 mWh cm(-3) at a power density of 0.02 W cm(-3), which is comparable to those of previously reported fiber-shaped supercapacitors. Additionally, CFASC exhibited good rate capability, long cycle life, and high volumetric capacitance (0.67 F cm(-3)) with excellent flexibility. The promising performance of CFASC illustrated its potential for portable and wearable energy storage devices. (c) 2018 Elsevier Ltd. All rights reserved.