Fabrication of electric papers of graphenenanosheet shelled cellulose fibres by dispersion and infiltration as flexible electrodes for energy storage

Abstract

An electrically conductive and electrochemically active composite paper of graphene nanosheet (GNS) coated cellulose fibres was fabricated via a simple paper-making process of dispersing chemically synthesized GNS into a cellulose pulp, followed by infiltration. The GNS nanosheet was deposited onto the cellulose fibers, forming a coating, during infiltration. It forms a continuous network through a bridge of interconnected cellulose fibres at small GNS loadings (3.2 wt%). The GNS/cellulose paper is as flexible and mechanically tough as the pure cellulose paper. The electrical measurements show the composite paper has a sheet resistance of 1063 Ω □⁻¹ and a conductivity of 11.6 S m⁻¹. The application of the composite paper as a flexible double layer supercapacitor in an organic electrolyte (LiPF₆) displays a high capacity of 252 F g⁻¹ at a current density of 1 A g⁻¹ with respect to GNS. Moreover, the paper can be used as the anode in a lithium battery, showing distinct charge and discharge performances. The simple process for synthesising the GNS functionalized cellulose papers is attractive for the development of high performance papers for electrical, electrochemical and multifunctional applications.