Nanocellulose/reduced graphene oxide composites for high performance supercapacitors

Nanocellulose/reduced graphene oxide (NC/rGO) composites were prepared by a simple one-step hydrothermal method using high-concentration graphene oxide (GO) solution as the reaction precursor and nanocellulose (NC) as the physical spacer and electrolyte reservoirs. Subsequently, we explored the potential of NC/rGO as electrode materials for supercapacitors. Due to its dense porous structure and large oxygen-containing functional group content, NC/rGO-1 prepared with 1 mL NC exhibited the best electrochemical performance. The binder-free symmetric supercapacitor based on NC/rGO-1 showed high gravimetric and volumetric specific capacitance of 269.33 F center dot g(-1) and 350.13 F center dot cm(-3) at a current density of 0.3 A center dot g(-1). These values can still reach 215.88 F center dot g(-1) and 280.62 F center dot cm(-3) at 10.0 A center dot g(-1) (80.15% of its initial value). The assembled device also displayed high gravimetric and volumetric energy densities (9.3 Wh center dot kg(-1) and 12.13 Wh center dot L-1) and excellent cycling performance (the initial specific capacitance decreased by only 6.02% after 10 000 cycles at 10 A center dot g(-1)).