Synthesis and properties of carbon black (CB)-added polyacrylonitrile (PAN)/nickel foam (NF) flexible electrodes by electrospinning, and their supercapacitive performance

Abstract

This research study presents the successful preparation of polyacrylonitrile/nickel foam (PAN/NF) and carbon black (CB)-added polyacrylonitrile/nickel foam (CB:PAN/NF) electrodes using an electrospinning method, along with a comprehensive discussion of their remarkable supercapacitive performances. Scanning electron microscope (SEM) investigations demonstrate a robust adhesion between polyacrylonitrile fibers and nickel foam, attributable to the application of an annealing process. Energy dispersive X-ray spectrometry (EDS) studies validate the elemental composition of the electrodes. To further characterize the structural properties, additional analyses are conducted utilizing X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. Structural characterizations indicate that both the incorporation of carbon black and the carbonization process yield beneficial contributions to the overall material properties. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) are employed to evaluate the thermal stability of the electrodes. Electrochemical investigations are performed using various techniques such as cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS), and Mott-Schottky (MS), all in a 1 M aqueous KOH solution. The addition of carbon black (CB) significantly improves the performance of the PAN/NF electrode, increasing the specific capacitance from 76.5 to 226.9 F g⁻¹. This study also examines the reaction kinetics that characterize the energy storage mechanisms of the electrodes. The enhancement of the electroactive surface area in PAN/NF due to CB loading is also confirmed by EIS analysis. In the existing literature, many studies focus on the direct use of PAN and its derivatives as electrode materials. However, this study is the first to investigate the energy storage capabilities of PAN in combination with a current collector, specifically nickel foam (NF). The results of this study provide strong evidence for CB:PAN/NF as a promising electrode material in flexible supercapacitors.