Fabrication and performance evaluation of symmetrical supercapacitor based on manganese oxide nanorods-PANI composite

Manganese oxide nanorods distributed over polyaniline (PANI) network was prepared by one step facile synthesis condition. pH of the reactant solution was tuned using sulfuric acid. Effect of pH on the morphology, chemical composition, structure and electrochemical performance of the prepared materials were studied. Thermal investigation reveals the decomposition of PANI at temperatures below 600 °C. Structural details and chemical composition of the compound was obtained from XRD, FTIR and XPS studies. α type MnO2 was found to be crystallized in the prepared MnO2-PANI composite. Single crystal manganese oxide nanorods distributed over the PANI network was cognizant from the FESEM and HRTEM investigations. Nanorods of average diameter 82 nm and length 482 nm were obtained without deploying any surfactants or templates. Electrochemical techniques like Cyclic Voltammetry (CV), Chronopotentiometry (CP) and Electrochemical Impedance Spectroscopy (EIS) were utilized. Study results indicate that the composites prepared shows excellent electrochemical performance. Among the prepared materials, MnP-46 exhibits a maximum specific capacitance of 687 Fg−1 at 5 mV s−1 scan rate and a capacitance retention of 95% over 2000 cycling. Promising performance of MnP-46 was further tested in a symmetrical two cell configuration. The cell was operative upto 1 V potential window. MnP-46 in a symmetrical arrangement demonstrates 179 Fg−1 at 5 mV/s scan rate. High conductivity of the electrode material was confirmed from the Nyquist plot.