聚吡咯/硝酸活化碳气凝胶纳米复合材料的制备表征及其在超级电容器中的应用

摘要

通过化学氧化聚合法制备出不同比例的聚吡咯(PPY)/硝酸活化碳气凝胶(HCA)复合材料。采用傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)表征材料的成分和形貌，结果表明，通过硝酸活化及与聚吡咯的复合，并未破坏碳气凝胶的多孔形貌，硝酸活化碳气凝胶及聚吡咯/硝酸活化碳气凝胶都仍然保持着原碳气凝胶的三维纳米多孔结构。采用对照实验的方法，设计并合成五组不同配比的复合材料，聚吡咯与硝酸活化碳气凝胶的质量比例分别为3：1、2：1、1：1、1：2、1：3，通过循环伏安法，恒流充放电，交流阻抗及循环性测试等考察材料的电化学性能。结果证明，当聚吡咯与硝酸活化碳气凝胶比例为1：1时，复合材料显示出最优电化学性能：比电容高达336 F∙g－1，是纯碳气凝胶(103 F∙g－1)的三倍有余，除此还显示出卓越的导电性与循环稳定性，2000次循环后仍保持初始电容的91%，具备优良的超级电容器电极材料性能。因此聚吡咯/硝酸活化碳气凝胶复合纳米材料是超级电容器的理想电极材料。%Polypyrrole (PPY)/nitric acid (HNO3) activated carbon aerogel (HCA) composites are prepared through chemical oxidative polymerization with different PPY/HCA mass ratios. Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) were employed to investigate the components and morphology of the samples. The results demonstrate that the synthesized materials maintain the three-dimensional nanoporous structure of the carbon aerogel (CA);the activation by nitric acid and composition with PPY do not destroy the porous structure of the carbon aerogel and the complex stil has the original three-dimensional nanoporous structure. Composites with different mass ratios (3:1, 2:1, 1:1, 1:2, 1:3) of PPY/HCA were prepared and the electrochemical properties were measured by cyclic voltammetry, galvanostatic charge-discharge test, and electrochemical impedance spectroscopy. The results confirm that the PPY/HCA composite with a ratio of 1:1 exhibits the best electrochemical performances;it has a high specific capacitance of 336 F∙g-1, which is more than two times higher than that of CA (103 F∙g-1);it also exhibits outstanding conductivity and cycling stability, retaining 91% of its initial capacitance after 2000 cycles. Therefore, this composite is quite a promising electrode material for supercapacitors.