Chemically Synthesized Iron-Oxide-Based Pure Negative Electrode for Solid-State Asymmetric Supercapacitor Devices

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Supercapacitors offer high power density and long cycle life, crucial for energy storage.
• Improving energy density in supercapacitors is a key research focus, often explored through asymmetric cell configurations.
• Research on negative electrodes for asymmetric supercapacitors remains limited compared to positive electrodes.

Purpose of the Study:

• To synthesize iron oxides with diverse morphologies for potential use as negative electrodes in supercapacitors.
• To investigate the electrochemical performance of α-Fe2O3 synthesized via chemical bath deposition.
• To fabricate and evaluate an asymmetric solid-state supercapacitor device utilizing the synthesized α-Fe2O3.

Main Methods:

• Chemical bath deposition was employed to synthesize iron oxides at varying temperatures.
• Morphological characterization identified nanosphere-like structures for α-Fe2O3.
• Electrochemical testing, including cyclic voltammetry (CV) and galvanostatic charge-discharge, was performed to assess capacitance and stability.

Main Results:

• α-Fe2O3 synthesized via chemical bath deposition exhibited a nanosphere-like morphology.
• The α-Fe2O3 negative electrode achieved a specific capacitance of 2021 F/g at 4 A/g.
• The electrode demonstrated remarkable capacitance retention of 96% over 5000 CV cycles.
• An asymmetric solid-state supercapacitor (α-Fe2O3-NF//Co3O4-NF) delivered 155 F/g and 21 Wh/kg at 4 A/g.

Conclusions:

• Nanostructured α-Fe2O3 synthesized through a simple chemical bath deposition method shows significant promise as a negative electrode material for supercapacitors.
• The high specific capacitance and exceptional cycling stability of α-Fe2O3 contribute to enhanced performance in asymmetric supercapacitor devices.
• This study highlights the potential of tailored iron oxide morphologies for advancing next-generation energy storage solutions.