The construction of carbon nanofiber composites modified by graphene/polypyrrole for flexible supercapacitors

Carbon nanofibers (CNFs) have attracted considerable attention because they make it possible for materials to have a variety of enhanced properities. However, the unsatisfied electrochemical performance of an individual component and the poor electrical conductivity caused by insufficient physical contact points become the fully addressing issues when CNFs are proposed as electrode material in a flexible supercapacitor. Hence, this paper proposes a feasible perspective on enhancing the electrochemical performance and flexibility via the method of electrostatic self-assembly and the dipping and drying strategy. The reduced graphene oxide (rGO) layer is uniformly anchored on the surface of SnCl2 modified carbon-based fiber polyacrylonitrile (PAN) fabricated by the electrospinning method. Pseudocapacitance material polypyrrole (PPy) is subsequently deposited and selected to design a composite PAN@rGO@PPy electrode. As expected, the as-constructed binder-free PAN@rGO@PPy electrode shows a specific capacitance of 203 F g(-1); the assembled flexible supercapacitor delivers a high energy density of 15 Wh kg(-1) together with a power density of 500 W kg -1, and displays remarkable cycling stability after 10,000 cycles. Finally, the flexibility via various deformations is discussed, meanwhile, the structural and compositional stability of the PAN@rGO@PPy electrode during long-term cycling test are demonstrated. In light of the facile preparation strategy and the excellent electrochemical performance, this work offers an instructive direction for the development of flexible energy storage devices.

Automated summary

Carbon nanofibers (CNFs) have attracted considerable attention due to their ability to enhance the properties of materials. This paper proposes a method to enhance the electrochemical performance and flexibility of CNFs by using electrostatic self-assembly and a dipping and drying strategy. The resulting PAN@rGO@PPy electrode shows specific capacitance of 203 F g(-1) and high energy density of 15 Wh kg(-1) in a flexible supercapacitor. It also demonstrates remarkable cycling stability after 10,000 cycles. The research provides valuable insights for the development of flexible energy storage devices.