A negative working potential supercapacitor electrode consisting of a continuous nanoporous Fe-Ni network

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Development of advanced electrode materials is crucial for next-generation energy storage devices.
• Existing negative electrode materials often face limitations in capacitance, stability, or cost.
• Iron-nickel (Fe-Ni) based nanomaterials present a promising avenue for electrochemical applications.

Purpose of the Study:

• To develop a novel class of electrochemical electrodes operating in a negative voltage window.
• To investigate the performance of electrodes synthesized from Fe-Ni nanoparticles.
• To assess the suitability of these electrodes for high-performance asymmetric supercapacitors.

Main Methods:

• Chemically prepared Fe-Ni nanoparticles were sintered into a porous nanoscale mixture.
• The mixture comprised an Fe-rich BCC Fe(Ni) phase and a Ni-rich FCC Fe-Ni phase.
• Electrochemical performance was evaluated through specific capacitance and cycling stability tests.

Main Results:

• Electrodes achieved a specific capacitance exceeding 350 F g⁻¹.
• Over 85% of maximum specific capacitance was retained after 2000 charge/discharge cycles.
• The Fe-rich phase converted to hydroxides, forming the active component, while the Ni-rich phase ensured conductivity and stability.

Conclusions:

• Compositionally optimized Fe-Ni electrodes demonstrate excellent electrochemical properties.
• The electrodes are self-supporting, cost-effective, and compatible with manufacturing processes.
• These Fe-Ni electrodes are highly suitable for use as negative electrodes in asymmetric supercapacitors.