A comparison of carbon supports in MnO2/C supercapacitors

Abstract

This article presents a comparison of three typical carbon supports, carbon nanotubes (CNTs), reduced graphene oxide (rGO), and acetylene black (AB), with regards to their performance in MnO₂ supercapacitors. To exclude the influence of MnO₂, uniform-sized MnO₂ nanoflakes with a width of ∼50 nm were used to fabricate three MnO₂/C composites. The working electrodes were prepared using a consistent procedure to keep all three types of MnO₂/C electrodes in the same configuration. The influence of these three carbon supports on capacitive performance and cyclability was studied. In particular, the capacitance contribution of carbon supports was subtracted from the overall capacitance. The contribution from MnO₂ was compared among these three types of composites and it was found that rGO could enhance the capacitive performance of MnO₂ at slow scan rates. However, MnO₂/CNTs and MnO₂/AB exhibited better capacitive performance at high rates and better stability.