School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
ACS Nano. 2010 Mar 23;4(3):1337-44. doi: 10.1021/nn901825y.
Microporous carbons, produced by selective etching of metal carbides in a chlorine-containing environment, offer narrow distribution of micropores and one of the highest specific capacitances reported when used in electrical double layer capacitors (EDLC) with organic electrolytes. Previously, the small micropores in these carbons served as an impediment to ion transport and limited the power storage characteristics of EDLC. Here we demonstrate, for the first time, how the preparation and application of templated carbide-derived carbon (CDC) can overcome the present limitations and show the route for dramatic performance enhancement. The ordered mesoporous channels in the produced CDC serve as ion-highways and allow for very fast ionic transport into the bulk of the CDC particles. The enhanced transport led to 85% capacitance retention at current densities up to approximately 20 A/g. The ordered mesopores in silicon carbide precursor also allow the produced CDC to exhibit a specific surface area up to 2430 m(2)/g and a specific capacitance up to 170 F/g when tested in 1 M tetraethylammonium tetrafluoroborate solution in acetonitrile, nearly doubling the previously reported values.
微孔碳通过在含氯环境中选择性刻蚀金属碳化物而制备，具有微孔分布狭窄的特点，并且在使用有机电解质的双电层电容器 (EDLC) 中具有报告的最高比电容之一。此前，这些碳中的微孔较小，这对离子传输造成了阻碍，限制了 EDLC 的储能特性。在这里，我们首次展示了如何通过制备和应用模板碳化硅衍生碳 (CDC) 来克服当前的限制，并展示了大幅提高性能的途径。所制备的 CDC 中的有序介孔通道作为离子通道，允许非常快速的离子传输进入 CDC 颗粒的主体。这种增强的传输使在高达约 20 A/g 的电流密度下电容保持率达到 85%。碳化硅前体中的有序介孔也使得所制备的 CDC 在测试于乙腈中的 1 M 四乙基铵四氟硼酸溶液时具有高达 2430 m²/g 的比表面积和高达 170 F/g 的比电容，几乎是之前报道值的两倍。
