Wet Spinning of Optimized Graphene Oxide Nanosheets for Enhanced Electrochemical Performance in Fiber-Based Supercapacitors

Graphene, a 2D carbon allotrope with remarkable characteristics like high conductivity, large surface area has shown potential as a good candidate for high-performance supercapacitors. The processability of its derivative, graphene oxide, into fibers enables the development of miniaturized wearable energy storage devices. However, the synthesis of pure graphene oxide and its subsequent reduction to restore conductivity remain a focus for research. Herein, we employ the improved Hummers’ method for graphene oxide synthesis, followed by meticulous washing to remove residual acids. The obtained graphene oxide was then transformed into conductive graphene fibers through a wet-spinning and hydroiodic acid (HI) reduction process. The resulting fibers showed a high areal capacitance of 175 mA cm⁻² in a three-electrode system. When assembled into a flexible supercapacitor, these fibers delivered an energy density of 8 μWh cm⁻² and areal capacitance of 60 mA cm⁻². This study demonstrates the potential of our strategy for fabricating fiber-based energy storage devices based on graphene.