Pristine graphene-ink for 3D-printed flexible solid-state supercapacitor

Due to its capacity to manufacture low-cost 3D-printed structures, 3D-printing technology offers a unique opportunity for the fast epitome of various applications. Using a typical fused deposition modeling 3D printer along with a Discovery extruder, a graphene-ink can be 3D printed to produce an interdigitated electrode (IDE) arrangement. This work fabricated a 3D-printed planar supercapacitor from pristine graphene-ink without using high-temperature processing or functional additives. The printable ink (89%) is formulated from pristine graphene without the addition of any functional additives. The symmetric flexible supercapacitor is demonstrated with an excellent specific capacitance of 137.50 F/g at 0.5 A/g and an energy density of 12.23 Wh/kg. The obtained gravimetric energy density beats reported earlier carbon-based supercapacitors that are 3D or inkjet printed. The flexibility and robustness of 3D-printed devices are achieved up to 150° folding angles. This work demonstrates an efficient and easy method for fabricating practical energy storage devices featuring a customizable shape and excellent flexibility.