MILD SOLUTION ROUTE TO MIXED-PHASE <font>MnO</font>₂ 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 MnO 2 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.