Interface metallization enabled an ultra-stable Fe₂O₃ hierarchical anode for pseudocapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Developing high-performance anodes is crucial for advancing pseudocapacitor technology.
• Iron oxide (Fe2O3) shows promise due to high theoretical capacitance but suffers from low conductivity and poor cyclability.
• Existing Fe2O3 anodes face limitations in practical applications.

Purpose of the Study:

• To engineer a stable and highly conductive Fe2O3-based anode for pseudocapacitors.
• To overcome the intrinsic limitations of Fe2O3 materials for energy storage.
• To demonstrate a novel interface engineering strategy for metal oxide-based energy storage.

Main Methods:

• Fabrication of a 3D nickel-metalized carbon nanofiber network.
• Deposition of Fe2O3 nanosheets onto the prepared conductive substrate.
• Characterization of electrochemical performance, including capacitance and cycling stability.
• Application of the interface metallization technique to a manganese dioxide (MnO2) cathode.

Main Results:

• The Fe2O3 anode composite achieved a high areal capacitance of 1.80 F cm⁻² at a mass loading of 4.2 mg cm⁻¹.
• Demonstrated ultra-high capacitance retention of 85.1% after 100,000 cycles.
• The nickel layer improved electronic conductivity, wettability, interface stability, and stress release.
• An MnO2 cathode using the same method showed 108.2% capacitance retention after 26,000 cycles.

Conclusions:

• The developed 3D nickel-metalized carbon nanofiber supported Fe2O3 nanosheet anode significantly enhances pseudocapacitor performance and durability.
• The interface metallization strategy offers a versatile approach for improving the stability of various metal oxide materials in energy storage.
• This work presents a promising pathway for next-generation pseudocapacitive energy storage devices.