In order to use fast pulses at scanning nanoelectrodes for electrodeposition, it is crucial to better understand and predict the spatial extent of charging by the nano-probe on the substrate-liquid interface below. Previous works have suggested semi-empirical models for the charging extent based on equivalent electrical circuits, where the interfaces and solution are modelled by measured capacitance and resistance, respectively. This simple description already captures the behavior of confined etching with ns potential pulses quite well using estimated values of the EDL capacitance and solution resistance . Nonetheless, it is difficult to unambiguously determine a capacitance for the EDL as a function of experimental parameters such as concentration , polarization , and frequency , and fitting of an electrical circuit model to the resolution obtained in pulsed etching has yielded unexpected values for the electrochemical fit parameters .