Polyaniline-based Symmetric solid-State supercapacitor

Supercapacitors, also known as ultracapacitors, are energy storage devices that can often be charged and discharged in seconds with extremely long cycle life [1, 2]. Supercapacitors are divided into two types: electrochemical double-layer capacitors (EDLCs) based on carbon electrodes that store and release energy by electrostatic charge separation at the electrode/electrolyte interface and pseudo-capacitors with certain metal oxides or conducting polymers as the active electrode materials that associate with adsorption and surface redox processes of the electroactive species [3]. Recently solid-state supercapacitors using a Nafion membrane as an electrolyte separator with the conductive composite electrodes have been studied [4]. In the present work, Nafion-based ionic polymer free metal nanocomposite (IPFMC) supercapacitor was fabricated. The suspension of graphene oxide/multiwalled carbon nanotube/PANI (GMP) was sprayed onto both sides of the Nafion membrane to complete the fabrication of the solid-state symmetric supercapacitor. Performance of the symmetric supercapacitor was investigated by Field emission scanning electron microscopy (FE-SEM) and Xray photoelectron spectroscopy (XPS). The electrochemical properties of symmetric solid-state supercapacitor were investigated by cyclic voltammetry (CV), galvanostatic charge–discharge (CD) and electrochemical impedance spectroscopy (EIS) techniques in 0.5M Na2SO4. The specific capacitance of 383.25 F.g-1 (326 mF.cm-2) was obtained for the GMP in solid-state supercapacitor cell at a scan rate of 10 mV.s-1, respectively.