Freestanding electrodes with polyaniline/Au derived from electrospun carbon nanofibers for high-performance supercapacitors

Abstract

Freestanding electrodes with the advantage of continuous conductive paths are more appealing for supercapacitor applications. In this work, using electrospun carbon nanofibers (CNFs) as conductive supports, Au nanoparticles (NPs) were embedded in polyaniline (PANI) polymer to construct a freestanding CNFs/PANI/Au electrode without binder. The binder-free CNFs/PANI/Au electrode with a meaningful three-dimensional (3D) network framework presents enhanced electrochemical properties. The specific capacitance of the CNFs/PANI/Au electrode (1144.5 F g⁻¹) was 2.69-fold that of CNFs/PANI, and was 5.85-fold that of CNFs/Au electrodes at a current density of 0.5 A g⁻¹ in the three-electrode configuration, when the atomic weight of Au NPs was about 2.23 at%. The satisfactory capacitance properties were connected with the freestanding structure and the efficient charge transfer that occurs at the CNFs/PANI/Au heterojunction interface. Besides, benefiting from the unique 3D self-supporting nanostructures, the CNFs/PANI/Au electrode exhibits long-term cycling stability with about 86.5% specific capacitance retention at 2 A g⁻¹ of initial capacitance after 5000 cycles. Our work provides a flexible strategy to construct freestanding and binder-free electrodes, which is expected to improve and optimize energy-storage devices.