Few-walled carbon nanotube-enhanced activated carbon supercapacitor performance in organic electrolyte at 4 V

The effects of few-walled carbon nanotubes (1–2 shell) are studied on an activated carbon-based supercapacitor (soft pack) in organic electrolyte at 4 V. The density of the electrode sheet and the resistance of the device decrease sustainably with the addition of carbon nanotubes of 1–5 wt%. The specific capacitance of the electrode, the energy density and the power density of the device all show typical volcano-type changing trends with the addition of carbon nanotubes, due to the trade-off effect of carbon nanotubes with smaller packing density, excellent electrical conductivity, and smaller surface area. The addition of 1% carbon nanotubes results in the highest values of these three aspects, as well as excellent cycling stability for 10 000 cycles.