High-performance supercapacitors using a nanoporous current collector made fromsuper-aligned carbon nanotubes

Abstract

Nanoporous current collectors for supercapacitors have been fabricated by cross-stackingsuper-aligned carbon nanotube (SACNT) films as a replacement for heavy conventional metalliccurrent collectors. The CNT-film current collectors have good conductivity, extremely low density (27 µg cm − 2), highspecific surface area, excellent flexibility and good electrochemical stability. Nanosized active materials suchas NiO, Co3O4 or Mn2O3 nanoparticles can be directly synthesized on the SACNT films by a straightforward one-step,in situ decomposition strategy that is both efficient and environmentally friendly. Thesecomposite films can be integrated into a pseudo-capacitor that does not use metallic currentcollectors, but nevertheless shows very good performance, including high specific capacitance (∼500 F g − 1, including the current collector mass), reliable electrochemical stability (<4.5% degradation in 2500 cycles) and a very high rate capability (245 F g − 1 at155 A g − 1).