One step fabrication of graphene/polypyrrole/Ag composite electrode towards compressible supercapacitor

Design and fabrication of compressible electrode for energy storage devices are highly demanded due to their wide applications. Here, compressible graphene/polypyrrole (PPy)/Ag composite electrodes were fabricated by one step hydrothermal treatment of pyrrole (Py) and silver nitrate (AgNO3) in graphene oxide (GO) aqueous solution. The resulting composite electrodes are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) and indicate that PPy and Ag nanoparticles are absorbed on graphene sheets. The capacitive behavior of the composite is investigated by using cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The electrochemical properties can be controlled by tuning the mass ratio of GO, Py monomer and AgNO3. The maximum specific mass capacitance of the electrode is 447 F g(-1). Importantly, the resulting electrode can be compressed both in dried state and in aqueous electrolyte. The assembled supercapacitor can be compressed up to 50% strain and maintains its original capacitance when released. This work indicates that it is possible to build high performance compressive conductors and supercapacitors by using graphene networks coated with conductive polymer and silver nanoparticles. (C) 2019 Elsevier B.V. All rights reserved.