Ni₃V₂O₈ Marigold Structures with rGO Coating for Enhanced Supercapacitor Performance

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors are crucial energy storage devices.
• Developing high-performance electrode materials is essential for advancing supercapacitor technology.
• Nickel-vanadium oxides and reduced graphene oxide are promising candidates for supercapacitor electrodes.

Purpose of the Study:

• To synthesize and characterize Ni3V2O8 (NVO) and NVO-reduced graphene oxide (NVO-rGO) composites.
• To evaluate the electrochemical performance of NVO-rGO as an electrode material for supercapacitors.
• To construct and test an asymmetric supercapacitor device using NVO-rGO.

Main Methods:

• Hydrothermal synthesis for NVO and NVO-rGO.
• X-ray diffraction (XRD) for crystalline structure analysis.
• Field emission scanning electron microscopy (FESEM) for morphology.
• X-ray photoelectron spectroscopy (XPS) for chemical states.
• Electrochemical impedance spectroscopy (EIS), Galvanostatic charge-discharge (GCD), and cyclic voltammetry (CV) for performance evaluation.

Main Results:

• NVO-rGO exhibited a specific capacitance of 132 F/g, energy density of 5.04 Wh/kg, and power density of 187 W/kg.
• An asymmetric supercapacitor using NVO-rGO and activated carbon achieved a specific capacitance of 7.85 F/g, energy density of 3.52 Wh/kg, and power density of 225 W/kg.
• The asymmetric supercapacitor demonstrated 99% columbic efficiency and 87% energy retention over cyclic stability tests.

Conclusions:

• NVO-rGO is a promising high-performance electrode material for supercapacitors.
• The composite structure enhances electrochemical properties compared to bare NVO.
• The developed asymmetric supercapacitor shows good energy and power density with stable cycling performance.