Porous aluminum supported carbon nanotubes-based 2.7 V supercapacitor for AC filtering

Supercapacitor is a promising solution for alternating current (AC) filtering to result in miniaturized electronic devices by virtue of its much higher specific capacitance than conventional mainstream electrolytic capacitors. Here, this work reports a novel electrode design for satisfying the high frequency response requirement of AC filtering based on the growth of carbon nanotube (CNT) electrode materials onto the pre-etched porous aluminum substrate, via an atmospheric pressure chemical vapor deposition (APCVD) method. The developed supercapacitors with such CNT electrodes displayed a high areal specific capacitance of 586 $\mathrm{\mu F}{\mathrm{cm}}^{-2}$, a phase angle of −80°, and a resistor-capacitor (RC) time constant of 0.232 milliseconds (ms) at 120 Hz, demonstrating both improved areal capacitance and the high frequency handling capability. More importantly, a wide voltage window (2.7 V) is promised by the utilization of a commercial organic electrolyte, which is benefiting to boost the energy density and facilitate the design of high voltage filtering device in comparison with the most reported aqueous filtering supercapacitors.