Anchoring polypyrrole on nitrogen and sulfur codoped graphene fibers to construct flexible supercapacitors

Graphene fiber-based flexible supercapacitors could function as flexible energy storage and supply equipment for wearable electronic devices. However, the future applications are restricted because of the low energy density for flexible supercapacitors. In this paper, the polypyrrole is anchored on nitrogen/sulfur co-doped graphene fibers (PPy/NSGF) by a hydrothermal self-assembly method and in situ polymerization process. The as-fabricated PPy/ NSGF possess a high specific areal capacitance of 424.8 mF cm-2 and an excellent energy density of 43.3 mu W h cm-2. The fiber-shaped supercapacitor assembled by PPy/NSGF can be utilized to power light. The improved properties of PPy/NSGF are mostly attributed to the increased electroactive sites from heteroatom nitrogen and sulfur codoping and in situ polymerization of polypyrrole. The produced graphene-based composite fibers are expected to become potential flexible electrode materials for fiber-shaped supercapacitors in future smart clothes and miniaturized flexible wearable electronics.