Preparation And Performance Study Of Polypyrrole/polyoxometalates Electrode Material For Electrochemical Supercapacitors

Organic-inorganic hybrid materials formed by conducting polymer and polyoxometalates (POMs) are a kind of novel electrochemical supercapacitors electrode material. In this paper, we prepared hybrid materials based on polypyrrole (PPy) and POMs by chemical oxidation polymerization method and electrochemical polymerization method respectively, and the electrochemical performance and capacitive behavior of the electrode material were studied by cyclic voltammetry and galvanostatic charge-discharge.The hybrid materials of PPy/P2Mo18 were prepared by electrodeposition on graphite plate via cyclic voltammetry technique for electrochemical supercapacitors application, and the scan rate and concentration of P2Mo18 solution in the process of preparing PPy/P2Mo18 electrode were explored. The PPy/P2Mo18-based hybrid electrode gave higher specific capacitance value, which was fabricated in the voltage range of 0.7~–0.1 V at a scan rate of 5 mV/s with the concentration of P2Mo18 solution for 0.030 mol/L. The PPy/P2Mo18 electrode prepared under the optimal experimental conditions was characterized by infrared spectra and cyclic voltammetry, and the capacitive behavior and electrochemical properties of the as-prepared electrode were evaluated by galvanostatic charge-discharge and electrochemical impedance spectroscopy.The hybrid materials of PPy/PMo12 and PPy/PW6Mo6 were prepared by chemical oxidation polymerization method for electrochemical supercapacitors application, and the electrochemical and capacitive performances of the electrode material were studied by cyclic voltammetry, galvanostatic charge-discharge and cycle-life test. The electrochemical supercapacitors based on PPy/PW6Mo6 hybrid materials had higher specific capacitance value and better cycling performance, which were evaluated by galvanostatic charge-discharge curves. Consequently, PPy/PW6Mo6 hybrid materials were suitable to use as electrochemical supercapacitors electrode material.The electrode materials of PPy/P2Mo18, MWNTs and PPy/P2Mo18-MWNTs were prepared for electrochemical supercapacitor application, and the electrochemical and capacitive properties of these materials were studied by cyclic voltammetry and galvanostatic charge-discharge. PPy/P2Mo18-MWNTs composite gave higher specific capacitance value than pure MWNTs or PPy/P2Mo18 hybrid material, which was calculated by galvanostatic charge-discharge curve. The result was attributed to the combination of electric double layer capacitance and pseudocapacitance. In addition, we explored the influence of content of MWNTs (25%, 33%, 50%) in composite materials on the specific capacitance. The result showed that the composite materials gave higher specific capacitance when the content of MWNTs was 25%.