Upgrading Structural Conjugation in Three-Dimensional Ni-Based Metal-Organic Frameworks for Promoting Electrical...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Metal-organic frameworks (MOFs) show potential for energy storage but suffer from poor electrical conductivity due to insulating organic linkers.
• Enhancing the conductivity of MOFs is crucial for their practical application in electrochemical devices.

Purpose of the Study:

• To develop a conjugated three-dimensional Ni-MOF with improved electroconductivity and electrochemical performance.
• To investigate the structure-property relationship between conjugation and electrochemical properties in MOFs.

Main Methods:

• Synthesized a conjugated Ni-MOF (Ni-BPE) using Ni2+, H3BTC ligand, and a vinyl-functionalized bipyridine linker (BPE).
• Compared the synthesized Ni-BPE with an analogous insulated Ni-MOF (Ni-BPY) constructed with an ordinary bipyridine linker (BPY).
• Evaluated the electroconductivity, specific capacitance, and performance in an asymmetric supercapacitor.

Main Results:

• The conjugated Ni-BPE exhibited a ~204-fold increase in electroconductivity compared to Ni-BPY.
• Ni-BPE showed a ~1.5-fold higher specific capacitance (633.2 F g-1) than Ni-BPY.
• The asymmetric supercapacitor using Ni-BPE achieved an energy density of 25.2 Wh kg-1 with 71.0% stability over 5000 cycles.

Conclusions:

• Structural conjugation is an effective strategy to enhance the electroconductivity and electrochemical performance of MOFs.
• The developed conjugated Ni-MOF offers a promising material for advanced electrochemical energy storage applications.
• This work provides a viable method for optimizing insulating MOFs for improved energy storage capabilities.