Silk Template Enabled Multi‐Hollow Graphene Fibers for Electrochemical Electrode

Abstract

Realizing high‐strength fiber electrodes with hollow/porous structure and high electrochemical activity is important for 1D energy storage devices and wearables. Herein, a graphene fiber with a tunable hollow structure, achieving fiber electrodes with a high surface specific area and electrochemical activity is developed. Specifically, silk is applied as a supporting template to manufacture a core–shell graphene oxide (GO) fiber with silk core by dry spinning technology. Subsequently, the composite fibers are treated with hydroiodic acid to reduce GO and silk is removed to obtain the hollow graphene fibers (HGFs). The multi‐hollow structure of the fibers could be adjusted by controlling the number of silk yarns. Due to the support of the silk template, GO shows lower dependence on the concentration for dry spinning, and improved spinnability and spinning efficiency of GO were demonstrated. Meanwhile, the traction of silk templates could effectively improve the orientation of GO nanosheets, enabling HGFs with enhanced mechanical strength that is tunable by controlling the number of silks. A typical two‐hole HGF exhibited a good electrochemical output with a specific capacity of 357.25 F m−2 at 200 μA, indicating the good potential of HGFs as the electrode material for the energy storage device, such as supercapacitors.