Setaria Viridis-Inspired Electrode with Polyaniline Decorated on Porous Heteroatom-Doped Carbon Nanofibers for Flexible Supercapacitors

Abstract

Carbon nanofibers are promising as primary electrode material for supercapacitors on account of high specific surface area, lightweight, superior physicochemical stability, rich-resource, and renewability. However, constructing porous and flexible carbon electrode materials with high capacitance for practical application remains challenging. Here, heteroatom-decorated hierarchical porous carbon nanofibers composites containing phosphazene (N3P3(p-OC6H4-p-CHO)6, HAPCP), polymethyl methacrylate (PMMA), and graphene oxide (GO) are prepared through one-step electrospinning and subsequent thermal treatment. Carbon lattice in the novel carbon nanofibers is linked to the backbones of alternating phosphorus-nitrogen to improve flexibility and electrochemical performance. Inspired by a biomimetic Setaria viridis-like structure, the polyaniline (PANI) decorated porous hybrid electrodes are prepared. The [email protected]/PMMA/HAPCP/PAN carbon nanofibers ([email protected]) covered by PANI nanofibers as a novel binder-free flexible electrode exhibit a high specific capacitance of 680.8 F g-1 at a current density of 0.5 A g-1. Capacitance retention remains 93.5% after 3000 cycles of charge-discharge process at a current density of 3 A g-1. Benefiting from the well-designed architecture, the as-assembled symmetric flexible all-solid-state supercapacitor displays a high energy density of 27.70 Wh Kg-1 with power density of 231.08 W kg-1 and good cycling stability with 84.50% capacitance retention after 1000 charge-discharge cycles at 5 A g-1, which paves a new avenue for construction of high-performance flexible binder-free energy storage devices.