Solid-state supercapacitors based on poly (3, 4-ethylendioxythiophene) (PEDOT) – Manganese oxide (MnO2) composite electrodes synthesized by single-step Co-Deposition for electrical energy storage

Abstract

In this work, solid-state supercapacitors were fabricated and characterized based on PEDOT-MnO2 electrodes and ionic liquid gel polymer electrolyte. The PEDOT-MnO2 electrodes were synthesized by single-step co-deposition technique in an aqueous solution consisting of 0.1 M LiClO4, 0.01 M EDOT monomer, 0.07 M SDS, and 0.3 M MnSO4. For comparative studies, another electrode was prepared from pure MnO2 that was electrochemically synthesized in exact same way with the exception that the EDOT monomer was not dissolved in the electrochemical deposition aqueous medium. The presence of both PEDOT and MnO2 in the electrochemically prepared electrodes was confirmed by Raman spectroscopy. The electrochemical performance characteristics were evaluated using cyclic voltammetry, charge-discharge tests, and electrochemical impedance spectroscopy. The PEDOT-MnO2 solid-state supercapacitor displayed an optimum areal capacitance density of 73.81 mF cm−2 at 10 mV s−1. The maximum energy and power densities were found to be 15.07 Wh kg−1 and 6.84 kW kg−1, respectively. In addition, the electrochemical performance of both PEDOT-MnO2 and pure MnO2 based solid-state supercapacitors was compared in terms of CV and CD and it was confirmed that the PEDOT-MnO2 electrode had superior electrochemical performance compared to the pure MnO2 electrode. Overall, the PEDOT-MnO2 based solid-state supercapacitor holds great potential for thin, flexible, and lightweight energy storage.