Nitrogen-Doped Mesoporous Carbons for Supercapacitor Electrodes with High Specific Volumetric Capacitance

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Supercapacitor miniaturization requires electrodes with controlled porosity for high energy utilization and coating density.
• Current nanocarbon electrodes often prioritize specific mass capacitance (Cm) by increasing surface area, which reduces coating density and specific volumetric capacitance (CV).

Purpose of the Study:

• To fabricate nitrogen-doped mesoporous carbon (NNCM) with tunable porosity for optimizing both Cm and CV.
• To investigate the relationship between pore structure, coating density, and capacitance in nanocarbon electrodes for supercapacitors.

Main Methods:

• Fabrication of nitrogen-doped mesoporous carbon (NNCM) with varying pore volumes and fixed mesopore sizes.
• Electrochemical characterization of NNCM electrodes to determine specific mass capacitance (Cm) and specific volumetric capacitance (CV).

Main Results:

• NNCM with high porosity (2.11 cm³ g⁻¹ pore volume, 663 m² g⁻¹ surface area) achieved the highest Cm (190 F g⁻¹) but lowest CV (124 F cm⁻³).
• NNCM with moderate porosity (1.22 cm³ g⁻¹ pore volume, 489 m² g⁻¹ surface area) exhibited the highest CV (200 F cm⁻³) with a lower Cm (147 F g⁻¹).

Conclusions:

• Achieving optimal supercapacitor performance, especially for miniaturized devices, necessitates a carefully controlled pore structure in nanocarbon electrodes.
• The study highlights the trade-off between Cm and CV and the importance of tailoring porosity for specific applications.