Influence of the reaction temperature on polyaniline morphology and evaluation of their performance as supercapacitor electrode

The polyaniline (PANI) nanostructures of tubular, spherical, and granules morphologies were synthesized by chemical oxidation approach in different reaction temperatures and used as the active electrode materials of symmetric redox supercapacitors. X-ray diffraction and scanning electron microscopy techniques are employed for characterization of these PANIs. With the initial and reaction temperature increase, the morphology of PANI turned from block to spherical and tubular. Electrochemical properties of these PANI electrodes are studied by cyclic voltammetry (CV), agalvanostatic charge-discharge test, and electrochemical impedance spectroscopy (EIS) in 1M H2SO4 aqueous solution. The highest electrochemical properties are obtained on the PANI with tubular morphology. The initial specific capacitance of tubular, spherical, and granules PANI are about 300, 300, and 290 F g(-1) at a constant current of 5 mA. Meanwhile, the retention of the tubular PANI capacitance after 500 charge-discharge cycles was 75%, whereas the spherical and granules PANI was only 35% and 57%. The results indicate that tubular PANI electrodes have potential applications as high-performance supercapacitors electrode materials. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3753-3758, 2013