Ultrastable Triazine-Based Covalent Organic Framework with an Interlayer Hydrogen Bonding for Supercapacitor...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) with redox-active units are promising for electrochemical energy storage.
• Designing COFs with enhanced charge transfer and structural stability is crucial for device performance.

Purpose of the Study:

• To synthesize and characterize a novel 2D COF (PDC-MA-COF) with redox-active triazine units for pseudocapacitance applications.
• To investigate the structural features, such as interlayer hydrogen bonding, that contribute to enhanced electrochemical performance.
• To evaluate the performance of the synthesized COF in supercapacitor devices.

Main Methods:

• Aldehyde-amine condensation reaction using 1,4-piperazinedicarboxaldehyde (PDC) and melamine (MA).
• Characterization of COF properties including surface area, pore size, pore volume, and nitrogen content.
• Electrochemical testing in three-electrode and two-electrode systems to determine specific capacitance, energy density, and power density.
• Cyclic stability testing of asymmetric supercapacitors.

Main Results:

• The synthesized PDC-MA-COF exhibited a high specific surface area (748.2 m² g⁻¹), narrow pore width (1.9 nm), large pore volume (1.21 cm³ g⁻¹), and high nitrogen content (47.87%).
• The material showed excellent electrochemical performance with a specific capacitance of 335 F g⁻¹ and 94 F g⁻¹ in three-electrode and two-electrode systems, respectively.
• An asymmetric supercapacitor (PDC-MA-COF//AC) achieved a high energy density of 29.2 Wh kg⁻¹ and retained 88% of its capacitance after 20,000 cycles.

Conclusions:

• The novel PDC-MA-COF, featuring redox-active triazine units and stabilized by interlayer hydrogen bonding, is a highly effective material for pseudocapacitive energy storage.
• The material's structural integrity and electrochemical properties contribute to its superior performance and cyclic stability.
• This work presents a new strategy for designing advanced redox-active COFs for high-performance energy storage applications.