Physicochemical and electrochemical behaviours of manganese oxide electrodes for supercapacitor application

Abstract

Objectives of this study are to probe the effect of reducing agents on physicochemical and electrochemical properties of manganese oxide. Manganese oxide is synthesized by chemical reduction of KMnO4 at room temperature using ethylene glycol, hydrazine hydrate, Na2S2O3, potassium iodide, formic acid, citric acid, and NaBH4. All as-prepared manganese oxide samples are analysed by powder XRD, FE-SEM and FT-IR. It is found that manganese oxide prepared using formic acid and sodium thiosulphate have nanorod or nanowire type morphology as confirmed by FE-SEM analysis. Electrochemical properties of samples are studied in aqueous medium (1 M Na2SO4) by cyclic voltammetry and galvanostatic charge-discharge techniques. Due to the rod type structure formic acid sample shows high surface area (117 m2g−1) and high porosity (0.1331 cc g−1), which results into high specific capacitance of 155 Fg−1 at 0.64 Ag−1. © 2020 Elsevier Ltd