Comprehensive approaches to three-dimensional flexible supercapacitor electrodes based on MnO2/carbon nanotube/activated carbon fiber felt

Abstract

With the fast development of portable and wearable devices, flexible supercapacitor electrodes are widely researched. Here, comprehensive approaches were designed to introduce carbon nanotube (CNT) and/or MnO2 into activated carbon fiber felt (ACFF) using “dipping and drying” method. Differences on micro-morphologies and electrochemical characteristics for prepared textiles were compared. High-performance flexible MnO2/CNT/ACFF composite electrodes were synthesized by introducing CNT and MnO2/CNT fillers successively. Compared with original ACFF textiles, significant improvements in electrochemical performance were achieved. Areal capacitance, energy density and power density of the composite textiles reached as high as 4148 mF cm−2, 141 μWh cm−2 and 4466 μW cm−2, respectively. Furthermore, flexible supercapacitors were fabricated based on the composite textile electrodes and gel electrolytes. When being bent at different angles or suffering deformations such as bending for 100 cycles, the flexible supercapacitors preserve almost all the capacitance, which indicates the excellent flexibility of the composite textile electrode. This work provides various approaches to design composite textiles, and the prepared MnO2/CNT/ACFF composite textile may be a promising electrode material for high-performance flexible supercapacitors.