Simulation Study of Electric Double-Layer Capacitance of Ordered Carbon Electrodes

Area of Science:

• Electrochemistry
• Materials Science
• Computational Modeling

Background:

• Supercapacitors are vital electrochemical energy storage devices known for high capacitance, power density, and long cycle life.
• Energy storage in supercapacitors primarily relies on the electric double-layer formation at the electrode-electrolyte interface.
• Understanding the factors influencing electric double-layer capacitance (EDLC) is crucial for designing advanced energy storage solutions.

Purpose of the Study:

• To conduct a simulation study of equilibrium electric double-layer capacitance (EDLC) in 3D mesoporous carbon electrodes.
• To investigate the influence of electrode morphology, thickness, and porosity on EDLC.
• To analyze the impact of interfacial polarization, ion crowding, and electric fields on electrolyte permittivity.

Main Methods:

• Utilized continuum theory to model the underlying processes governing EDLC in mesoporous carbon electrodes.
• Simulated EDLC in simple cubic morphology and interdigitated electrode configurations.
• Analyzed the effects of electrode thickness, porosity, and electric field on capacitance and electrolyte properties.

Main Results:

• Diffuse-layer specific capacitance in ordered mesoporous carbon electrodes ranged from 3.2-13.3 μF cm⁻² with varying electrode thickness.
• Stern-layer specific capacitance was 167.6 μF cm⁻², and total equilibrium EDLC ranged from 3.1-12.3 μF cm⁻².
• Diffuse-layer specific capacitance in carbonized interdigitated electrodes ranged from 118.7 to 352.0 μF cm⁻² with varying electrode width.

Conclusions:

• Electrode porosity significantly enhances capacitance by increasing surface area.
• Electrode thickness and interdigitated electrode width are critical parameters affecting EDLC.
• The developed modeling and simulation approach is adaptable for various mesoporous electrodes by adjusting parameters and geometry.