Single‐walled Carbon Nanotubes as Electrode Materials for Supercapacitors

Large‐scale synthesized single‐walled carbon nanotubes (SWNT) prepared by electric arc discharge method and a mixture of NiO and Y 2 O 3 as catalyst have been used as electrode materials for supercapacitors. N 2 adsorption/desorption measurement shows that the SWNT is a microporous and mesoporous material with specific surface area 435 m 2 ·g −1 . The specific capacitance of the nitric acid treated SWNT in aqueous electrolyte reaches as high as 105 F/g, which is a combination of electric double layer capacitance and pseudocapacitance. The SWNT‐based capacitors also have good charge/discharge reversibility and cycling perdurability.