Capacitive Properties Of Polyaniline/Manganese Oxide Composites Prepared By Interface Synthesis Using4-amino Thiophenol As The Structure-directing Agent

Polyaniline/Manganese dioxide composites were successfully obtained on the Au line treated by4-ATP in situ chemical oxidation under N2protecting, using KMnO4as the oxidant. The PANI/MnOx composites were characterized by FT-IR, TG-DTA, XRD, SEM, XPS and the capacitance performance was studied by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy (EIS). The characteristic absorption peaks of polyaniline and manganese oxide were observed in FT-IR spectrum. The thermo gravimetric-differential thermal analysis curves show that the content of chemically bonded water and PANI in the sample is high. XRD analysis results show that polyaniline and manganese oxide were amorphous. The SEM results show that the composites were porous three-dimensional nanostructured microsphere (200nm diameter). XPS analysis results show that the atomic ratio of Mn to O is approximately0.4, thereby confirming the nonstoichiometric performance of MnOx.The single-factor test was conducted to investigate the influence of concentrations of, N2protecting,4-ATP concentrations, the ratios of aniline to HCl, the ratios of aniline to KMnO4and the electrode mass to capacitance performance of composites. The results show that composites show fine capacitance performance under following condition:the concentration of aniline was0.15M, pH value was4, the concentration of4-ATP was1mM, the ratio of aniline to HCl was1:1, the ratio of aniline to KMnO4was1:1. The single electrode specific capacitance was up to822F/g, with the mass0,20mg, and then decreased5.8%with the mass increasing to1.00mg.The results of cyclic voltammetry and chronopotentiometry of PANI/MnOx composites indicated that the composites were with fine capacitance performance over a potential range of0.0to0.9V, and the single electrode specific capacitance was up to832F/g when the electrode mass was0.18mg at lmA/cm2and then decreased9.7%at5mA/cm2. It could keep an acceptable cycling performance of83.7%retention after1000cycle, which was much higher than single electrode of PANI, MnOx.electrochemical impedance spectroscopy exhibit good pseudocapacitive performance at0.4V. A symmetric capacitor, was assembled by using PANI/MnOx as both of the electrodes and0.5M Na2SO4as the electrolyte. It displayed a energy density of22.8Wh/kg at the power density of1248W/kg, which was much higher than symmetric capacitor assembled by MnOx-MnOx (13.8Wh/Kg) and PANI-PANI (6.3Wh/Kg).