Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
ACS Appl Mater Interfaces. 2009 Nov;1(11):2536-43. doi: 10.1021/am900575v.
The synthesis and characterization of a new PEDOT-carbon composite prepared using a microporous carbon template are described. The electrochemical behavior of this composite, as well as that of three other colloidal materials-PEDOT-silica, PEDOT, and microporous carbon particles-is investigated with respect to their suitability as electrode materials in supercapacitors. This was accomplished by a combination of cyclic voltammetry and galvanostatic charge/discharge cycles. It was found that the PEDOT-silica composite had the lowest specific capacitance of the four materials (ca. 60 F g(-1)) and also the worst retention of the capacitance at high scan rates. In the case of pure PEDOT, microporous carbon, or PEDOT-carbon microspheres, the specific capacitances of the materials were dramatically higher (C(M) = 115, 109, and 106 F g(-1), respectively). These values are higher than those of either unstructured electropolymerized PEDOT or commercially available high-surface-area carbon. The pure PEDOT materials retained this high capacitive behavior even at faster scan rates, although the capacitance of the carbon and PEDOT-carbon microspheres dropped substantially. These results are interpreted in the context of the local microstructure of the individual colloidal particles, as well as the overall film morphology. The morphologies of both the individual particles and the electrode films were investigated by field-emission scanning electron microscopy. Due to the monodisperse nature of the microspheres, films composed of these materials necessarily possess an interconnected network of interstitial pores that allow for facile ionic diffusion. This allows for more penetration of the conjugated polymer by the ionic electrolyte and therefore higher capacitances relative to the bulk materials. These results demonstrate the feasibility of utilizing monodisperse colloidal microparticles containing conjugated polymers as electrode materials for high-energy and high-power-density supercapacitors.
描述了一种使用微孔碳模板制备的新型 PEDOT-碳复合材料的合成和表征。通过循环伏安法和恒电流充放电循环，研究了该复合材料以及另外三种胶体材料（PEDOT-二氧化硅、PEDOT 和微孔碳颗粒）作为超级电容器电极材料的电化学行为，以评估它们的适用性。结果表明，PEDOT-二氧化硅复合材料的比电容最低（约 60 F g(-1)），在高扫描速率下电容保持率最差。对于纯 PEDOT、微孔碳或 PEDOT-碳微球，材料的比电容要高得多（C(M) = 115、109 和 106 F g(-1)）。这些值高于未结构化的电聚合 PEDOT 或市售的高比表面积碳。即使在更快的扫描速率下，纯 PEDOT 材料也保持了这种高电容行为，尽管碳和 PEDOT-碳微球的电容大大下降。这些结果是根据单个胶体颗粒的局部微结构以及整体薄膜形态来解释的。通过场发射扫描电子显微镜研究了单个颗粒和电极薄膜的形态。由于微球的单分散性质，由这些材料组成的薄膜必然具有互连成网络的间隙孔，允许离子的扩散。这使得更多的离子电解质能够渗透到共轭聚合物中，从而相对于块状材料具有更高的电容。这些结果表明，使用含有共轭聚合物的单分散胶体微球作为高能量和高功率密度超级电容器的电极材料是可行的。
