聚吡咯/MnO_(2)纸电极的制备及光热效应增强电容性能

Preparation of Polypyrrole/MnO_(2) Paper Electrode and Its Photothermal Effect to Enhanced Capacitor Performance

通过湿化学法与低温界面聚合法在慢速滤纸上依次沉积二氧化锰(MnO_(2))与聚吡咯(PPy),制备出PPy/MnO_(2)纸基复合材料。利用红外光谱、扫描电镜、循环伏安、恒电流充放电、交流阻抗等手段对该复合材料的结构和性能进行了表征。研究表明:PPy的沉积较好地保留了滤纸的多孔结构,并能覆盖MnO_(2)颗粒,形成较大活性面积;其中MnO_(2)/PPy-400单电极的比电容可达1487.1 mF/cm^(2);在光强为1 kW/m2的模拟太阳光下,组装的对称型超级电容器的比电容是在无光照条件下的5倍,表现出优异的光热效应增强性能。

The performance of supercapacitor degenerates at low temperature,even fails to work sometimes.Solar photothermal conversion provides a new direction for the performance improvement of supercapacitor.Manganese dioxide(MnO_(2))has a high specific capacity,while it should be compounded with other active materials due to its low electric conductivity.Therefore,this study aimed to improve the performance of MnO_(2)-based supercapacitor using the photothermal effect of polypyrrole(PPy),which exhibited excellent light absorption ability and pseudocapacitance property.MnO_(2) and PPy were successively deposited on slow filter paper by wet chemistry method and low-temperature interfacial polymerization approach,and PPy/MnO_(2) paper-based composites with different PPy contents were prepared.The structures and properties of the composites were characterized by Fourier transform infrared spectroscopy,scanning electron microscopy,cyclic voltammetry,galvanostatic charge/discharge,and AC impedance spectroscopy.The results showed that the porous structure of filter paper was well preserved after PPy deposition,and MnO_(2) was covered to form a large active area.The specific capacitance of MnO_(2)/PPy-400 single electrode reached 1487.1 mF/cm^(2),67%higher than that of pure PPy electrode.Under the simulated sunlight with the intensity of 1 kW/m2,the surface temperature of the assembled symmetrical supercapacitor increased from 21.2 °C to 46.7 °C after 10 min. The specific capacitance of the symmetrical supercapacitor assembled by the paper electrode with PPy of 400.0 μL was 52.9 mF/cm^(2) with illumination, five times that in dark, suggesting excellent photothermal effect to enhanced capacitor performance.