Sandwich-Like Holey Graphene/PANI/Graphene Nanohybrid for Ultrahigh-Rate Supercapacitor

Abstract

Hierarchically porous holey graphene/PANI/ graphene nanohybrid is fabricated by adopting a facile twostep process in which PANI/graphene hybrid was first synthesized hydrothermally and then wrapped with a layer of holey graphene. The resulted sandwich-like structure cannot only promote electronic transmission and ionic diffusion, but also contribute to a prominent rate capability. A symmetric supercapacitor was assembled with the obtained holey graphene/PANI/graphene nanohybrid, exhibiting a maximum specific capacitance of 437 F•g −1 at 1 A•g −1 , an energy density of 55 Wh•kg −1 at 900 W•kg −1 , an ultrahigh-rate performance (retained 43% capacitance at 100 A•g −1 ), as well as a long-term life (84% retention after 5000 loops at 10 A•g −1 ). The present work may provide an insight for designing highperformance symmetric supercapacitor.

Facile Method of Fabricating Interdigitated and Sandwich Electrodes for High-Performance and Flexible Reduced Graphene Oxide@Polyaniline Nanocomposite Supercapacitors

“…In the Raman spectrum, no significant peak arising from the @PANI is observable, which might be due to the peaks of PANI being very weak and/or the PANI chains have been enveloped by the reduced graphene oxide sheets. This illustrates that PANI in the sample is well wrapped in the layer of reduced graphene oxide sheets, which is in agreement with the previous reports. ,,, …”

“…This illustrates that PANI in the sample is well wrapped in the layer of reduced graphene oxide sheets, which is in agreement with the previous reports. 14,23,25,26 Electrochemical investigations including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) tests are useful electrochemical methods, which are used to measure properties, mechanism, and kinetic parameters of electrode reactions. For real practical applications of rGO@PANI-NR nanocomposites as an electrode active material of SCs, electrochemical investigations were done in a two-electrode system (packed supercapacitor), according to Stoller and Ruoff's recommendations 27 and others.…”

Nanostructured Polyaniline/Graphene/Fe2O3 Composites Hydrogel as a High-Performance Flexible Supercapacitor Electrode Material

“…Flexible supercapacitors (FSCs) are new emerging energy storage devices having great mechanical compliance and high power density, making them suitable as power back-ups for next-generation flexible electronics because they could work under bending and even twisting states. , Depending upon the storage mechanism, supercapacitors (SCs) can be categorized as pseudocapacitors , and electrochemical double-layer capacitors (EDLCs) . Carbon-based materials such as carbon fibers, carbon nanotubes, activated carbon, and graphene (GN) , are consider as best electrode materials for EDLCs,whereas conjugated polymers (CPs) and transition metal oxides (TMOs) and phosphides have been used as electrodes in Faradaic-capacitors/pseudocapacitors because of their reversible redox processes and high surface area. It is recognized that conducting polymers are optimal electrode materials for stretchable energy storage devices …”

Hydrothermal Synthesis of Three-Dimensional Perovskite NiMnO3 Oxide and Application in Supercapacitor Electrode

“…To evaluate the electrochemical performance of the NiMnO3 electrode at a high current density, constant charge/discharge experiments were conducted at the current densities of 1, 3, 5, and 7 mA•cm -2 in the voltage range of 0-0.9 V under 6.0 M KOH electrolyte. The higher current density restricts electrolyte ion movement and decreases specific capacitance [49]. As shown in Figure 7b, the specific capacitance at 1 mA•cm -2 was higher compared with the other current densities because the electrolyte ion diffusion occurs easily at a low current density.…”