Electrochemical Double-Layer Capacitor based on Carbon@ Covalent Organic Framework Aerogels

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Growing energy demands necessitate advanced materials for energy storage.
• Covalent organic frameworks (COFs) offer promising properties like porosity and ion transport for electrode applications.
• Electrochemical double-layer capacitors (EDLCs) are attractive for high-power, long-cycle life energy storage.

Purpose of the Study:

• To investigate the electrochemical performance of flexible COF-aerogel electrodes (ECOFs) for EDLC applications.
• To evaluate the capacitance, cycle stability, and ion transport characteristics of ECOFs.

Main Methods:

• Fabrication of flexible COF-electrodes (ECOFs) from COF-aerogels via compression.
• In-depth electrochemical characterization of ECOFs as EDLC devices.
• Analysis of charge/discharge cycles and capacitance retention at various scan rates.

Main Results:

• ECOFs demonstrated outstanding capacity retention (nearly 100%) after 10,000 cycles.
• Achieved the highest reported areal capacitance for COFs in aqueous electrolytes at high scan rates (9.55 mF cm⁻² at 1000 mV s⁻¹).
• Hierarchical porosity in ECOFs facilitated enhanced ion transport and fast interface polarization (low τ₀).

Conclusions:

• Flexible COF-electrodes are highly effective materials for fabricating high-performance EDLCs.
• The unique structure of ECOFs enables superior ion diffusion and electrochemical stability.
• These findings highlight the potential of ECOFs as a novel material for next-generation energy storage devices.