The excellent and characteristic capacitor performance of pure single-walled carbon nanotubes (SWNTs), which differ from conventional activated carbon electrodes, is reported. SWNTs with little bundling showed higher specific capacitance than activated carbons. High operating voltage can be expected for pure SWNTs without metal contamination and graphene edge structure.

• Osamu Tanaike(Energy Technology Research Institute, Advanced Industrial Science and Technology (AIST))
• Don N. Futaba(Nanotube Research Center, AIST)
• Kenji Hata(Nanotube Research Center, AIST)
• Hiroaki Hatori(Energy Technology Research Institute, Advanced Industrial Science and Technology (AIST))