Synthesis and characterization of electrochemical double layer capacitors using aligned architectures of carbon nanotubes.

摘要

Electrochemical double layer capacitors, (EDLC's or supercapacitors) have received a lot of attention as viable electrical energy storage devices due to their ability for delivering high powers. Supercapacitor devices were fabricated using freestanding aligned multiwall carbon nanotubes (AMWNTs) as well as AMWNTs grown on metallic alloy (inconel 600) substrates. A novel technique of air assisted chemical vapor deposition (CVD) method was employed for the synthesis of the AMWNTs. The carbon nanotubes (CNTs) were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The performances of the supercapacitor devices were tested using a variety of standard techniques such as cyclic voltammetry, galvanostatic constant current charge/discharge, and impedance spectroscopy. The maximum value of specific capacitance, measured at 5 mA constant discharge current, for various devices were in the range of 14.6-21.57 F/g for the supercapacitors fabricated from CNT grown on an inconel substrate. The maximum value of energy density and power density of the whole capacitor devices were 1.48 Wh/Kg and 2695.87 W/Kg, respectively. These results show that the electrodes fabricated from Inconel sheets with AMWNT grown directly on them have the potential to be superb electrode material for the fabrication of high performance EDLC's.