Simultaneously Armored and Active Graphene for Transparent and Flexible Supercapacitors

Transparent and flexible supercapacitors (TFSCs) as indispensable components for future transparent and flexible electronics have attracted significant interests. The Ag nanowires/poly(ethylene terephthalate) (PET) transparent conductive electrodes (TCEs) exhibit strong competitiveness applied in the TFSCs due to the exceptional conductivity and transparency. However, the environmental tolerance of Ag nanowires such as oxidation and sulfurization limits the reliability. Herein, electric-double-layer TFSCs based on Ag nanowires/PET TCEs as current collectors are reported. More importantly, a seamless, uniform, and flexible graphene layer behaves as armored and active components simultaneously for the TFSCs, by a facile electrodeposition process. On the one hand, the flexible graphene layer can isolate the Ag nanowires away from the oxidation well, particularly in the condition of electrolyte. On the other hand, the laminated graphene layer with wrinkles can store electrons, and the copercolating network of graphene layer and Ag nanowires can transport the electrons efficiently, cyclically accomplishing the operation of storage and transport, by which the synergistic effect endows the TFSCs with decent optical and electrochemical performances. The interfacial capacitance is evaluated to discuss the relationship between the structure of graphene layer and the measured capacitance. This facile process provides a rational architecture and insights into TFSCs.