Cu@Fe-Redox Capacitive-Based Metal-Organic Framework Film for a High-Performance Supercapacitor Electrode

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) are promising electrode materials for supercapacitors due to their porosity and redox capacitive sites.
• Doping MOFs can modify their electronic structure and surface reactivity, potentially enhancing electrochemical performance.
• Iron-based MOFs are actively researched for energy storage applications.

Purpose of the Study:

• To synthesize and characterize a copper-doped iron-based MOF (Cu@Fe-MOF/NF) thin film on a nickel foam substrate.
• To evaluate the electrochemical performance of the Cu@Fe-MOF/NF material as an electrode for supercapacitors.
• To assess the performance of an asymmetric solid-state supercapacitor device utilizing the developed electrode.

Main Methods:

• Drop-casting of Cu@Fe-MOF/NF thin film onto a 3D-nickel foam (NF) substrate.
• Electrochemical characterization including specific capacitance measurements at various current densities.
• Fabrication and testing of an asymmetric solid-state supercapacitor (ASSSC) device using Cu@Fe-MOF/NFǁrGO/NF electrodes.

Main Results:

• The Cu@Fe-MOF/NF electrodes exhibited a unique micro-sized bipyramidal structure with nanoparticles.
• A high specific capacitance of 420.54 F g⁻¹ at 3 A g⁻¹ was achieved, which is double that of the undoped Fe-MOF/NF.
• The ASSSC device demonstrated an energy density of 44.20 Wh.kg⁻¹ and 88% capacitance retention after 5000 cycles.

Conclusions:

• Copper doping significantly enhances the electrochemical performance of iron-based MOF electrodes for supercapacitors.
• The Cu@Fe-MOF/NF material shows excellent potential for high-performance electrochemical energy storage.
• The developed ASSSC device exhibits promising energy density and long-term cycling stability.