Flexible self-charging supercapacitor based on graphene-Ag-3D graphene foam electrodes. (September 2018)

• Record Type: Journal Article
• Authors: Manjakkal, Libu; Núñez, Carlos García; Dang, Wenting; Dahiya, Ravinder
• Is Part Of: Nano energy. Volume 51(2018)
• Page Start: 604
• Page End: 612
• Publication Date: 2018-09
• Subjects: Supercapacitor -- Graphene foam -- Self-powered systems -- Wearable systems -- pH sensor -- Energy storage; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2018.06.072
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: A flexible three-dimensional porous graphene foam-based supercapacitor (GFSC) is presented here for energy storage applications. With a novel layered structure of highly conductive electrodes (graphene-Ag conductive epoxy–graphene foam), forming an electrochemical double layer, the GFSC exhibits excellent electrochemical and supercapacitive performance. At a current density of 0.67 mA cm −2, the GFSCs show excellent performance with areal capacitance (38 mF cm −2 ) about three times higher than the values reported for flexible carbon-based SCs. The observed energy and power densities (3.4 µW h cm −2 and 0.27 mW cm −2 respectively) are better than the values reported for carbon-based SCs. Analyzed under static and dynamic bending conditions, the GFSCs are stable with up to 68% capacitance retention after 25000 charge–discharge cycles. The light-weight, cost-effective fabrication and no self-heating make the GFSCs a promising alternative to conventional source of energy in the broad power density ranging from few nW cm −2 to mW cm −2 . In this regard, GFSC was integrated with a flexible photovoltaic cell resulting in a flexible self-charging power pack. This pack was successfully utilized to power continuously a wearable CuO nanorod based chemi-resistive pH sensor. Graphical abstract: fx1 Highlights: Development of Flexible graphene foam-Ag-graphene sheet-based supercapacitor with capacitance GFSC 38 mF/cm 2 . Supercapacitor exhibited energy density 3.4 μWh/cm 2 and 0.27 mW cm − 2 power density. Integration of supercapacitor with flexible solar cell and flexible CuO nanorod based pH sensor. Development of fully flexible self-charging power pack (FSPP) for flexible/wearable sensor system. Developed supercapacitor performed 25000 charge-discharge cycles.