Abstract: Activated carbon nanotubes were obtained by the activation of carbon nanotubes using KOH as activator at high temperature. The specific surface area and pore volume of the obtained activated carbon nanotubes were 3 and 1.5 times as large as that of the pristine carbon nanotubes, respectively. The two kinds of carbon nanotubes were used as the electrode materials of electrochemical supercapacitors and the simulated electrochemical supercapacitors were assembled in the glove box filled with argon air. The electrochemical capacitance of the activated carbon nanotubes was twice as large as that of the pristine carbon nanotubes by test under constant current chargingdischarging. So, the activated carbon nanotubes with a short cut length and rough tube surface are more suitable in using as the electrode materials of electrochemical supercapacitors than the normal carbon nanotubes.

Key words: Electrochemical supercapacitors, Carbon nanotubes (CNTs), Activation