Investigation of knot-linker effects on charge storage in triangular COF supercapacitors: A molecular dynamics investigation

ZG Peng and N Li and YY He and XR Shi and XR Meng and M Lu and K Xu, JOURNAL OF ENERGY STORAGE, 131, 117484 (2025).

DOI: 10.1016/j.est.2025.117484

This study investigates triangular two-dimensional covalent organic frameworks (2D COFs) with tunable pore geometries as high-performance electrode materials for electrochemical double-layer capacitors (EDLCs). Using molecular dynamics simulations with the ionic liquid BMIMBF4 in an AA-stacked electrode system, we evaluate how structural features and pore size influence ion transport and capacitance. The inherent sharp-angled structures of triangular 2D COFs enhance ion-electrode interactions by concentrating ion distributions within confined channels. Results show that ordered pore channels significantly improve ion-electrode interactions compared to conventional porous carbons. Thin-layer electrodes exhibit superior capacitance and faster charging kinetics due to shortened ion diffusion paths and optimized surface utilization. Sharp-angled architectures enable efficient ion alignment, crucial for maximizing charge storage efficiency. Smaller pores strengthen ion alignment but limit external double-layer formation, while larger knots increase interfacial charge contributions. Structural design modulates these effects: HBC-knotted COFs achieve higher area- specific capacitance, whereas HPB-knotted variants enhance mass-specific performance through increased surface area. These findings highlight the potential of 2D COFs as next-generation supercapacitor materials, offering new strategies for optimizing capacitance and advancing energy storage technologies. Future research should focus on complex simulations and experimental validation to fully realize their practical potential.

Return to Publications page