Selenium-Bridged Bimetallic Selenide Heterostructure for Superior Sodium Storage

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Developing high-performance anode materials is critical for sodium-ion hybrid capacitors (SIHCs).
• Achieving a balance between anode-cathode kinetics and capacity is essential for SIHC performance.
• Tailored architectures, high capacity, and structural stability are key requirements for advanced anode materials.

Purpose of the Study:

• To construct a carbon-coated bimetallic selenide heterostructure (Fe3Se4/MnSe@C) for SIHC applications.
• To engineer interfacial selenium-bridged bonds to enhance structural stability and charge transport.
• To investigate the synergistic effects of heterostructures and interfacial bonds on electrochemical performance.

Main Methods:

• Interface engineering using a Fe-Mn Prussian blue analogue precursor.
• Synthesis of a carbon-coated bimetallic selenide heterostructure (FMSC).
• Electrochemical testing in sodium-ion batteries (SIBs) and SIHC full cells.
• Electrochemical kinetics analysis and theoretical calculations.

Main Results:

• The FMSC electrode exhibited stable cycling in SIBs, retaining 336 and 367 mA h g⁻¹ after 1000 cycles at 5 and 10 A g⁻¹, respectively.
• A built-in electric field at the interface facilitated charge redistribution and heterostructure stabilization.
• The SIHC full cell achieved an energy density of 104 W h kg⁻¹ at 101 W kg⁻¹ and retained 90% capacity after 3000 cycles.
• Synergy between selenium-bridged bonds and heterostructures enhanced structural stability, charge transfer, and reaction kinetics.

Conclusions:

• The developed FMSC material shows significant potential for practical sodium-based energy storage.
• Interface engineering is an effective strategy for designing high-performance anode materials.
• The FMSC anode contributes to the high energy and power density of SIHCs.