Electrochemical capacitive performances of ordered carbon nanotube arrays

Arrays of ordered carbon nanotubes (OCNT) was synthesized successfully using aluminated mesoporous silica as hard template. XRD tests and TEM observations showed that OCNT was composed of carbon nanotube arrays in p6mm symmetry. N-2 sorption analyses demonstrated that OCNT possesses typical mesoporous structure and centralized mesopore distribution. OCNT are superior to Maxsorb, an active carbon with super high surface area, in capacitive behavior and power output due to their ordered pore-structure, which favors the fast diffusion of hydrated ions. As evidenced by cyclic voltammetry measurements, OCNT show good capacitive behaviors (exhibiting a high capacitance of 180 F/g even at very high sweep rate of 50 mV/s, as compared with much reduced capacitance of 73 F/g for Maxsorb at the same sweep rate). OCNT can provide very high power density while still maintaining good energy density, thus having potential uses in electrochemical double layer capacitor (EDLC), particularly where both high power output and energy density are required.