Facile Synthesis and Outstanding Supercapacitor Performance of Ternary Nanocomposite of Silver Particles Decorated N/S Dual-Doped Graphene and MoS₂ Microspheres Stabilized by Graphene Quantum Dots

Abstract

The ternary nanocomposite of silver particles decorated N/S dual-doped graphene and molybdenum disulfide microspheres (Ag-MoS2/NSG) is prepared by hydrothermal-chemical reduction method with graphene quantum dots (GQDs) as additives and graphene oxide, sodium molybdate and silver nitrate as main raw materials. For comparison, the binary composites of Ag-MoS2, Ag-NSG and MoS2/NSG are also prepared and discussed. In addition, the physicochemical and electrochemical properties of GQDs are studied, and the dynamic analysis of Ag-MoS2/NSG is also carried out. Results show that the ternary composite of Ag, MoS2 and NSG can effectively prevent the lamellar superposition and agglomeration of graphene, which effectively improves the specific surface area and conductive properties of the composite. The specific capacitance of Ag-MoS2/NSG is 1124.3 F•g-1 at 10 mV•s-1, and the specific capacitance retention is 95.2% after 10000 constant current charge/discharge loops. The asymmetric button supercapacitor device assembled with NSG and Ag-MoS2/NSG has a maximum energy density of 82.5 Wh•kg-1 (900 W•kg-1).

Li-Ni Metal Oxides Processed with Rapid Atmospheric-Pressure-Plasma Jet for Flexible Gel-Electrolyte Li-Ion Hybrid Supercapacitors

“…EIS of Li-ion HSCs.-Figure 9 shows the EIS results and equivalent circuit model. [81][82][83] The equivalent circuit consists of the solution resistance R s ; charge transfer resistance R ct , and Warburg resistance W o used for fitting the curve in the low-frequency part and the double-layer capacitance CPE1. The Nyquist diagram is seen to consist of two parts.…”

Heteroatom Codoped Graphene: The Importance of Nitrogen

“…Symmetric and asymmetric supercapacitor electrodes were created using S and N codoped graphene. − As early as 2015, Xing et al prepared three-dimensional S and N codoped graphene hydrogels using thiocarbohydrazide as a reducing and doping agent. Thanks to the highly porous architecture and presence of dopants, the materials exhibited a high specific capacitance of 141.1 F/g in KOH electrolyte.…”

“…A maximum energy density of 14.8 Wh/kg and excellent cycle stability were reported. In general, the porous nature of the S and N based materials is crucial for the performance of the supercapacitor. − Comparing the performances of the electrodes prepared is not easy because different conditions are employed. Thus, I refer the reader to refs − gathered on this topic.…”