Coral-like PEDOT Nanotube Arrays on Carbon Fibers as High-Rate Flexible Supercapacitor Electrodes
Fei Niu, Rui Guo, Liqin Dang, Jie Sun, Qi Li, Xuexia He, Zong‐Huai Liu, Zhibin Lei
Abstract
Integration of conductive polymers with flexible substrate to construct an electronically conductive and mechanically flexible electrode is of great significance for a flexible energy storage device. This work reports a facile method to prepare coral-like poly(3,4-ethylenedioxythiophene) (PEDOT) nanotube arrays on textile carbon fibers (TCs) for high-rate supercapacitor application. The ZnO nanowires grown on TCs serve as a sacrificial template. Electrochemical polymerization of 3,4-ethylenedioxythiophene followed by template removal of ZnO nanowires yields a hybrid composed of PEDOT nanotubes vertically grown on TC (TC@PEDOT). The strong interfacial interactions between nanotubes and substrate afford the hybrid with superior mechanical flexibility and high conductivity (790 S m–1). More importantly, the tubular structure enables ∼88% PEDOT to be involved in the reversible redox reaction, delivering a specific capacitance 184 F g–1 in 1.0 M H2SO4 electrolyte with 88% capacitance retention after 10 000 cycles. A solid-state TC@PEDOT-based supercapacitor with PVA-H2SO4 as gel electrode exhibits a high-rate capability with a relaxation time constant (τ0 = 0.96 s) very close to that in aqueous H2SO4 electrolyte (τ0 = 0.87 s). Moreover, it can withstand various bending and twisting tests without notable performance loss, giving the TC@PEDOT hybrid great promise as a high-rate electrode for flexible energy storage devices.