Al-Based MOF-Derived Amorphous/Crystalline Heterophase Cobalt Sulfides as High-Performance Supercapacitor Materials

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Transition metal sulfides (TMSs) offer high theoretical capacitance for supercapacitors.
• Their application is limited by slow charge transfer and few active sites.

Purpose of the Study:

• To develop novel TMS electrode materials with improved electrochemical performance.
• To investigate the structure-property relationships of amorphous/crystalline (a/c) heterophase TMSs derived from MOFs.

Main Methods:

• A self-sacrificial template strategy using Al-based MOFs (CAU-1 and CoAl-MOF) was employed.
• Acid etching and sulfuration were used to synthesize a/c-Co(Al)S-1 with a 3D network structure.
• Electrochemical performance was evaluated using supercapacitor devices.

Main Results:

• The a/c-Co(Al)S-1 material exhibited a high specific charge of 1791.8 C g -1 at 1 A g -1.
• The assembled a/c-Co(Al)S-1//AC supercapacitor delivered a high energy density of 77.1 Wh kg -1 at 800 W kg -1.
• The device showed good durability with 87.4% capacitance retention over 10,000 cycles.

Conclusions:

• The unique 3D network structure of a/c-Co(Al)S-1 enhances interfacial contact and ion diffusion.
• This novel TMS material shows significant potential for high-performance supercapacitor applications.
• The MOF-derived a/c heterophase strategy is effective for creating advanced electrode materials.