Influence of the OMCs pore structures on the capacitive performances of supercapacitor

Abstract

AbstractIn the present study, two mesoporous carbons OMC‐KIT‐6 and OMC‐SBA‐16 were nanocasted using mesoporous silica of KIT‐6 and SBA‐16 as templates and furfuryl alcohol as carbon precursor. Transmission electron microscopy (TEM) and X‐ray diffraction (XRD) characterizations confirmed that the resultant samples are mesoporous carbons, and the as‐prepared OMC‐KIT‐6 has an Ia3d ordered structure, whereas OMC‐SBA‐16 belongs to Im3m space group. The surface area and the average pore size are (1658 m2 g−1 and 3.4 nm) for OMC‐KIT‐6 and (1638 m2 g−1 and 2.9 nm) for OMC‐SBA‐16, respectively. The results of cyclic voltammograms and galvanostatic charge‐discharge tests show that these two mesoporous carbons have excellent capacitive performances. But the difference of capacitive behavior between OMC‐KIT‐6 and OMC‐SBA‐16 may be a result of the difference of pore geometries of these two carbons. In order to find out the function of mesopore in a supercapacitor, we compared the capacitive properties of mesoporous and microporous carbons; the experiment results indicated that these two kinds of carbon exhibit nearly ideal capacitive behavior at low scan rate. When the scan rate is enhanced up to 50 mV s−1 the performance of mesoporous carbon is more stable than microporous carbon. This outcome demonstrated that mesopore plays an important role in forming double layers in the electrode materials. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.