In-Situ Sulfuration of CoAl Metal-Organic Framework for Enhanced Supercapacitor Properties

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitors require efficient electrode materials, but their design is challenging.
• Metal-organic frameworks (MOFs) offer tunable precursors for advanced materials.

Purpose of the Study:

• To synthesize a novel cobalt sulfide (Co(Al)S) heterostructure from an Al-based MOF for supercapacitor applications.
• To investigate the structure-property relationships of the synthesized material for enhanced electrochemical performance.

Main Methods:

• Ion exchange and acid etching of an Al-based MOF.
• Subsequent controlled sulfidation to form crystalline/amorphous Co(Al)S heterophase.
• Characterization of the 3D nanosheet-interconnected network architecture and specific surface area.
• Electrochemical testing of the Co(Al)S material in supercapacitor devices.

Main Results:

• A 3D nanosheet-interconnected network architecture with a large specific surface area was successfully formed.
• The optimal Co(Al)S material exhibited a high specific capacity of 1791.8 C g⁻¹ at 1 A g⁻¹.
• The Co(Al)S//AC device achieved an energy density of 72.3 Wh kg⁻¹ at a power density of 750 W kg⁻¹.
• Excellent rate capability and cycling stability were demonstrated.

Conclusions:

• The Co(Al)S heterostructure derived from MOFs is a promising electrode material for high-performance supercapacitors.
• The unique network structure and heterophase contribute to enhanced ion/electron transport and charge separation.
• The developed synthesis strategy is applicable to other MOF-derived electrode materials for energy storage.