Electrical conductivity of monolithic and powdered carbon aerogels and their composites

Abstract

The electrical conductivity of powdered carbon aerogels is one of the key factors required for electro-chemical applications. This study investigates the correlation between the structural, physical, mechanical and electrical properties of pure and activated carbon aerogels, as well as aerogel-composites. The thermal activation with carbon dioxide led to higher electrical conductivity and a decrease in density and particle size. Furthermore, the influence of applied force, compressibility of aerogels and aerogel composites on electrical conductivity was studied. A number of different carbonaceous powdered additives with various morphologies, from almost spherical to fiber- and flake-like shaped, were investigated. For two composites, theoretical values for conductivity were calculated showing the great contribution of particle shape to the conductivity. The results show that the conductive behavior of composites during compression is based on both the mechanical particle arrangement mechanism and increasing particle contact area.