Microscopic Origin of Electrochemical Capacitance in Metal-Organic Frameworks

12 May 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Electroconductive metal-organic frameworks (MOFs) have emerged as high-performance electrode materials for supercapacitors, but the fundamental understanding of the underlying chemical processes is limited. Here, the electrochemical interface of Cu3(HHTP)2 (HHTP=2,3,6,7,10,11-hexahydroxytriphenylene) with an organic electrolyte is investigated using a multi-scale quantum-mechanics/molecular-mechanics (QM/MM) procedure and experimental electrochemistry measurements. Our simulations reproduce the observed capacitance values and reveals the polarisation phenomena of the nanoporous framework. We find that excess charges mainly form on the organic ligand and cation-dominated charging mechanisms give rise to greater capacitance. The spatially confined electric double-layer structure is further manipulated by changing the ligand from HHTP to HITP (HITP=2,3,6,7,10,11-hexaiminotriphenylene). This minimal change to the electrode framework not only increases the capacitance but also increases the diffusion coefficients of in-pore electrolytes. The performance of MOF-based supercapacitors can be systematically controlled by modifying the ligating group.


charging mechanism

Supplementary materials

Supplementary Information for Microscopic Origin of Electrochemical Capacitance in Metal-Organic Frameworks
This PDF file includes: Supplementary Figure 1 to 33, Supplementary Table 1 to 2, Supplementary Note 1 to 2, and Supplementary Reference.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.