Wang Da-Wei, Li Feng, Fang Hai-Tao, Liu Min, Lu Gao-Qing, Cheng Hui-Ming
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
J Phys Chem B. 2006 May 4;110(17):8570-5. doi: 10.1021/jp0572683.
Ordered mesoporous materials show great importance in energy, environmental, and chemical engineering. The diffusion of guest species in mesoporous networks plays an important role in these applications, especially for energy storage, such as supercapacitors based on ordered mesoporous carbons (OMCs). The ion diffusion behavior in two different 2-D hexagonal OMCs was investigated by using cyclic voltametry and electrochemical impedance spectroscopy. In addition, transmission electron microscopy, small-angle X-ray diffraction, and nitrogen cryosorption methods were used to study the pore structure variations of these two OMCs. It was found that, for the OMC with defective pore channels (termed as pore packing defects), the gravimetric capacitance was greatly decayed when the voltage scan rate was increased. The experimental results suggest that, for the ion diffusion in 2-D hexagonal OMCs with similar mesopore size distribution, the pore packing defect is a dominant dynamic factor.
有序介孔材料在能源、环境和化学工程领域具有重要意义。客体物种在介孔网络中的扩散在这些应用中起着重要作用，特别是对于能量存储，例如基于有序介孔碳（OMC）的超级电容器。通过循环伏安法和电化学阻抗谱研究了两种不同的二维六方OMC中的离子扩散行为。此外，还使用透射电子显微镜、小角X射线衍射和氮低温吸附方法研究了这两种OMC的孔结构变化。研究发现，对于具有缺陷孔道（称为孔填充缺陷）的OMC，当电压扫描速率增加时，重量电容会大幅衰减。实验结果表明，对于具有相似介孔尺寸分布的二维六方OMC中的离子扩散，孔填充缺陷是一个主要的动力学因素。
