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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 H 2 SO 4 electrolyte with 88% capacitance retention after 10 000 cycles. A solid-state TC@PEDOT-based supercapacitor with PVA-H 2 SO 4 as gel electrode exhibits a high-rate capability with a relaxation time constant (τ 0 = 0.96 s) very close to that in aqueous H 2 SO 4 electrolyte (τ 0 = 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.

As a conductive polymer with great potential, poly(3,4-ethylenedioxythiophene) (PEDOT) has been developed as a high-rate supercapacitor electrode but stores less energy due to its limited theoretical capacity. In this work, the growth of PEDOT nanotube arrays on flexible Ti foil (Ti@PEDOT) is reported with significantly enhanced performance by incorporating highly pseudocapacitive polyaniline (PANi). The as-prepared Ti@PEDOT nanotube arrays offer a three-dimensionally conductive network. Such arrays have been successfully connected with each other through the uniform coating of PANi onto the surface, thus contributing a substantial pseudocapacitance. By constructing the above novel structure, the Ti@PEDOT-PANi hybrid electrode delivers a nearly 10 times enhancement of areal capacitance (2876 mF cm −2 at 5 mA cm −2 ) together with a remarkable rate performance (85% capacitance retention at 100 mA cm −2 ). Moreover, a flexible supercapacitor assembled with the Ti@PEDOT-PANi electrode also exhibits a high-rate property with a relaxation time constant as small as 0.83 s (τ 0 = 0.83 s) and a volumetric energy density of 15.9 mW h cm −3 under the power density of 178.9 mW cm −3 . The cycling stability of such a device is also remarkable, indicating the great advantages of the Ti@PEDOT-PANi electrode. More gratifying, such device can endure continuous bending at a maximum angle of 145°for 200 cycles. The present work can provide theoretical and technical support for the design and development of polymer-based flexible electrodes which possess both large areal capacitance and fast charging−discharging rates.

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