Cellulose nanofibrils-reduced graphene oxide xerogels and cryogels for dielectric and electrochemical storage applications

Abstract

The effect of structure (density and porosity) and composition (ratio) of composites prepared from cellulose nanofibrils (CNF) and reduced graphene oxide (RGO) as film-like xerogels and porous cryogels, respectively, were investigated related to their dielectric performance and electrochemical storage abilities. A very small content (5 wt%) of RGO incorporated xerogelic film of a denser and layered structure shows relatively high dielectric constant of ∼85 and ∼164 and an ac electrical conductivity of 0.0028 S/m2 and 0.0072 S/m2 at 270 K and 370 K, respectively, at a high frequency of 1 MHz showing their suitability for high temperature dielectric storage applications. On the other hand, a high specific capacitance of ∼460 F/g and electrochemical resistance of 12–15 Ω cm2 was observed for well-aligned and longitudinal-oriented micro-porous cryogel, indicate on its suitability as electrodes for electrochemical storage devices.