One‐step hydrothermal method produced all graphene fiber electrode for high‐performance supercapacitor

Abstract

Summary With the popularity of wearable and flexible electronics, developing wearable electrodes and energy storage systems is highly desired. Herein, high‐performance reduced graphene oxide (RGO) fiber electrode is synthesized by an efficient one‐step hydrothermal method. Firstly, graphene oxide (GO) dispersion with an ordered lyotropic nematic liquid crystal structure is prepared to assemble fibers without the aid of any supporting surfactants or polymers. The shaping and reducing processes of GO dispersion into RGO fiber are effectively condensed together through hydrothermal reaction in a capillary. The produced RGO fiber electrode, without any extra active material, exhibits excellent energy storage performance. The specific capacitance reaches 246.01 F g −1 at 1 A g −1 . Moreover, the energy storage performance is cyclically stable with capacitance retention of 90.80% after 100 000 cycles at 10 A g −1 . Furthermore, it also possesses excellent flexibility, with 98.94% of the capacitance maintained after bending 10 000 times. Beyond supercapacitor, the produced all graphene fiber with excellent performance can be well applied to develop various flexible fiber energy systems and wearable electronics.