High-performance three-dimensional nanoporous gold based electrodes for flexible all-solid-state supercapacitors

High-performance, flexible reduced graphene oxide (rGO)-polypyrrole (PPy)/nanoporous gold (NPG) electrodes are prepared by a facile electrochemical interfacial polymerization method using NPG as the substrate. Owing to the synergistic effect of three-dimensional (3D) porous architecture and superior electrical conductivity, the prepared electrode not only exhibits a good areal capacitance (232 mF/cm 2 ), but also shows high volumetric capacitance (555.6 F/cm 3 ). Hence, an all-solid-state supercapacitor assembled with rGO-PPy/NPG electrodes exhibits a high energy density of 238.8 mW h/cm 3 . Besides, this flexible supercapacitor also shows excellent cycling stability with retention of 91% with respect to the initial capacitance after 2000 galvanostatic charge–discharge cycles. This work offers a novel avenue for designing flexible supercapacitor.