A flexible supercapacitor based on vertically oriented ‘Graphene Forest’ electrodes

Abstract

Vertically-grown graphene electrodes are developed for flexible electric double-layer capacitors (EDLC). Solid-state electrolytes and large area flexible electrodes are essential parts for wearable applications. In this work, the vertically-grown graphene electrodes were fabricated by a plasma-enhanced chemical vapor deposition process and applied to flexible electrodes of EDLC. The areal capacitance of the capacitor based on vertical graphene is 2.45 mF cm⁻², which is much better even with solid electrolytes when compared to other reported vertical graphene capacitors. The capacitance also shows good flexibility and it remains unaltered even after 100 000 times of bending or 180 degree folding. These unique features of the capacitor could be ascribed to a discrete ‘tree-like’ morphology of the vertical graphene, which has not been known before.