Nanostructured composite electrode based on manganese dioxide and carbon vulcan–carbon nanotubes for an electrochemical supercapacitor

The An Ha, Van Man Tran and My Loan Phung Le

Abstract

Nanostructured composite electrodes of MnO₂/C with various types of carbons (noir, mesoporous carbon and carbon vulcan) were prepared by chemical reduction. The combination of carbon vulcan and carbon nanotubes (CNTs) was also studied at the total content of 30 wt%, etc. The morphology and structure of samples were examined by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The specific capacitances of the composite electrodes were determined by cyclic voltammetry measured in 2M NaCl at different potential scan rates. The carbon addition improves specific capacitance (SC) as well as specific surface area (SSA). Compared to other carbon, the highest SC value was reached at 30% content for carbon vulcan. The addition of 5 wt% CNTs in MnO₂/carbon vulcan increased the SC up to 199 F g⁻¹ and improved significantly the cycling behavior of composite electrode