MILD SOLUTION ROUTE TO MIXED-PHASE MnO2 WITH ENHANCED ELECTROCHEMICAL CAPACITANCE

Abstract

Mild chemical bath route at 60–80°C led to the redox reaction between MnSO 4 and KMnO 4 to form MnO 2. The as-synthesized MnO 2 was a mixture of both α- and δ-phases, which has enhanced electrochemical capacitance performances. Pure α-, δ- and γ- MnO 2 were also chemically prepared in the current solution system. The electrochemical performances of the as-prepared MnO 2 samples were evaluated as an electrode for supercapacitor by recording cyclic voltammograms and galvanostatic charge-discharge curves. The crystallographic structure of MnO2 was found to be determined by the chemical bath reaction temperature and time. In the current work, we purposefully designed the optimum reaction parameters to synthesize high performance mixed-phase MnO 2 through mild chemical bath route, ultimately for enhancing the capacitance of powder-based electrodes.