Carbon matrix nanostructured composites as a new type of supercapacitor electrode materials

Abstract

Carbon matrix nanocomposites C / Au and C / Mn x O y are obtained by a reduction of HAuCl 4 and KMnO 4 precursor solutions with single-walled carbon nanotubes or highly porous carbon materials obtained by high-temperature alkaline activation of various metamorphism degree coals. The morphology of the nanocomposite materials is studied by the electron microscopy. It is found that the filler introduction slightly reduces the specific surface of matrices and, due to the blocking of meso-and micropore volumes, filler nanoparticles do not precipitate in the pores of a predominantly microporous matrix and partially decorate them in mixed-type matrices (meso-and micropores). Nanocomposites have been studied as supercapacitor electrode materials. It is established that decorating the matrix surface with both types fillers (Au, which increases the electrical double layer capacitance, and Mn x O y , which is electrochemically active in a given potential window due to the occurrence of Red-O x electrode processes) results in an increase in the supercapacitor electrodes capacitance. The most significant effect is observed for composites based on the SWCNT and highly porous Boghead in the region of high potential scan rates by a factor of 3.4 – 4.5, and in the region of low rates (2.5 – 2.8), depending on the filler. The results obtained allow one to consider the composites C / Au and C / Mn x O y as promising materials for the development of SC electrodes.