Hexaazatriphenylene-Quinone Covalent Organic Polymers as a Platform for Stable and High-Performance Supercapacitors

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• High-performance supercapacitors demand a balance of capacitance, energy density, power density, and cycling stability.
• Covalent organic polymers (COPs) are promising for energy storage due to their tunable structures and high surface areas.

Purpose of the Study:

• To synthesize and characterize heteroatom-doped, spin-active, and redox-active hexaazatriphenylene-quinone COPs.
• To evaluate their electrochemical performance for supercapacitor applications.
• To establish a molecular-to-device design framework for advanced energy storage materials.

Main Methods:

• Complementary mechanochemical and solution-phase synthesis of COPs.
• Electrochemical characterization including capacitance, energy density, power density, and cycling stability measurements.
• Spectroscopic analysis, electrochemical impedance spectroscopy, and electronic structure simulations.

Main Results:

• Synthesized a family of robust, spin-active, and redox-active COPs with strong pseudocapacitive activity.
• COP-2 achieved high areal capacitance (6214 mF/cm²) and energy density (1.91 mWh/cm²).
• Demonstrated high-rate capability (51.4 mW/cm²) and excellent cycling stability (82.1% retention after 50,000 cycles).

Conclusions:

• Heteroatom-doped, spin-active COPs exhibit significant potential for advanced supercapacitors.
• The interplay of redox activity and spin delocalization is crucial for charge storage.
• A molecular design framework for spin-active porous polymers in energy storage was established.