One pot preparation of tin sulfide decorated graphene nanocomposite for high performance supercapacitor applications

Rational Fabrication of Nickel Vanadium Sulfide Encapsulated on Graphene as an Advanced Electrode for High-Performance Supercapacitors

Supercapacitors (SCs) are widely recognized as competitive power sources for energy storage. The hierarchical structure of nickel vanadium sulfide nanoparticles encapsulated on graphene nanosheets (NVS/G) was fabricated using a cost-effective and scalable solvothermal process. The reaction contents of the composites were explored and optimized. TEM images displayed the nickel vanadium sulfide nanoparticles (NVS NPs) with 20-30 nm average size anchored to graphene nanosheets. The interconnection of graphene nanosheets encapsulating NVS nanoparticles effectively reduces the ion diffusion path between the electrode and electrolyte, thereby enhancing electrochemical performance. The NVS/G composite demonstrated improved electrochemical performance, achieving a maximum of 1437 F g-1 specific capacitance at 1 A g-1, remarkable rate capability retaining of 1050 F g-1 at 20 A g-1, and exceptional cycle stability with 91.2% capacitance retention following 10,000 cycles. The NVS/G composite was employed as a cathode, and reduced graphene oxide (rGO) was used as an anode material to assemble a device. Importantly, asymmetric SCs using NVS/G//rGO achieved 74.7 W h kg-1 energy density at 0.8 kW kg-1 power density, along with outstanding stability with 88.2% capacitance retention following 10,000 cycles. These superior properties of the NVS/G electrode highlight its significant potential in energy storage applications.

Recent progress in graphene and its derived hybrid materials for high-performance supercapacitor electrode applications

Graphene, the most fascinating 2D form of carbon with closely packed carbon atoms arranged in a layer, needs more attention in various fields. For its unique electrical, mechanical, and chemical properties with a large surface area, graphene has been in the limelight since its first report. Graphene has extraordinary properties, making it the most promising electrode component for applications in supercapacitors. However, the persistent re-stacking of carbon layers in graphene, caused by firm interlayer van der Waals attractions, significantly impairs the performance of supercapacitors. As a result, many strategies have been used to get around the aforementioned problems. The utilization of graphene-based nanomaterials has been implemented to surmount the aforementioned constraints and considerably enhance the performance of supercapacitors. This review highlights recent progress in graphene-based nanomaterials with metal oxide, sulfides, phosphides, nitrides, carbides, and conducting polymers, focusing on their synthetic approach, configurations, and electrochemical properties for supercapacitors. It discusses new possibilities that could increase the performance of next-generation supercapacitors.

Fabrication of Flexible Poly(m-aminophenol)/Vanadium Pentoxide/Graphene Ternary Nanocomposite Film as a Positive Electrode for Solid-State Asymmetric Supercapacitors

In this study, poly(m-aminophenol) (PmAP) has been investigated as a multi-functional conductive supercapacitor binder to replace the conventional non-conductive binder, namely, poly(vinylene difluoride) (PVDF). The kye benefits of using PmAP are that it is easily soluble in common organic solvent and has good film-forming properties, and also its chemical functionalities can be involved in pseudocapacitive reactions to boost the capacitance performance of the electrode. A new ternary nanocomposite film based on vanadium pentoxide (V₂O₅), amino-functionalized graphene (amino-FG) and PmAP was fabricated via hydrothermal growth of V₂O₅ nanoparticles on graphene surfaces and then blending with PmAP/DMSO and solution casting. The electrochemical performances of V₂O₅/amino-FG/PmAP nanocomposite were evaluated in two different electrolytes, such as KCl and Li₂SO₄, and compared with those of V₂O₅/amino-FG nanocomposite with PVDF binder. The cyclic voltametric (CV) results of the V₂O₅/amino-FG/PmAP nanocomposite exhibited strong pseudocapacitive responses from the V₂O₅ and PmAP phases, while the faradaic redox reactions on the V₂O₅/amino-FG/PVDF electrode were suppressed by the inferior conductivity of the PVDF. The V₂O₅/amino-FG/PmAP electrode delivered a 5-fold greater specific capacitance than the V₂O₅/amino-FG/PVDF electrode. Solid-state asymmetric supercapacitors (ASCs) were assembled with V₂O₅/amino-FG/PmAP film as a positive electrode, and their electrochemical properties were examined in both KCl and Li₂SO₄ electrolytes. Although the KCl electrolyte-based ASC has greater specific capacitance, the Li₂SO₄ electrolyte-based ASC delivers a higher energy density of 51.6 Wh/kg and superior cycling stability.