Preparation of carbon nanotube-activated carbon hybrid electrodes by electrophoretic deposition for supercapacitor applications

Abstract

This study examines the possibility of preparing activated carbon (AC) and carbon nanotubes (CNT) based electrodes for supercapacitors by a facile electrophoretic deposition (EPD) method. The EPD method is able to deposit AC and CNTs on a stainless steel substrate, fabricating a three dimensional porous structure. The weight proportions of CNT to AC in the as-prepared electrodes are estimated by thermogravimetric analysis. The amount of CNTs in the electrodes can be easily controlled by tuning the solution bath composition before the EPD process. The effects of the presence of CNTs in the AC electrode on supercapacitor performance are also examined in this work. The addition of CNTs not only increases the specific capacitance but also enhances the rate capability of the AC electrodes. After a cyclic stability test for 11,000cycles, the as-prepared AC/CNT electrode shows capacitance retention of 85%, clearly demonstrating the commercial applicability of the electrodes fabricated by EPD process.