Design principles for improved supercapacitors should be underpinned by a fundamental understanding of charging mechanisms. Such understanding provides deeper insights into why certain electrode and electrolyte combinations perform better than others, and could inspire new routes to increased performance. To date, only a few computationally-focussed studies have examined the charging mechanisms of MOF-based supercapacitors, with the first such study modelling the doublelayer structure and charging process of Ni-based layered MOFs with a variety of pore sizes using molecular dynamics (MD) simulations. More recently, Walsh et al. expanded on this by studying the electrochemical interface of the layered MOF Cu 3 (HHTP) 2 (HHTP = 2,3,6,7,10,11hexahydroxytriphenylene) with tetraethylammonium tetrafluoroborate (TEABF 4 ) in acetonitrile electrolyte using a multiscale quantum-mechanics/molecular-mechanics (QM/MM) approach. In contrast to the previous approach, this accounted for the heterogeneous electronic structure of the MOF electrode and revealed how it changes with charging. Excitingly, comparison of simulated capacitance values, obtained for a range of different charging mechanisms, with experimental results indicated that cations are the dominant species participating in charge storage for Cu 3 (HHTP) 2 , with minimal involvement of the anions. However, there has been a lack of experimental work to study the ion electrosorption in layered MOFs to confirm these findings. One technique that can be used to study ion adsorption during charging is electrochemical quartz crystal microbalance (EQCM), a technique that has been used extensively in nanoporous carbon and MXene devices to understand their charging mechanisms with a range of electrolytes. However, no studies have used EQCM to look at the double-layer charging of layered MOFs. Employing this technique to study the charge storage mechanisms of MOF-based devices alongside measurements of their electrochemical performance would allow the link between charging mechanisms and performance to be better understood.