Fig. 7: Impedance theory of the eSCM method.

a An ideal impedance response of a porous electrode in blocking condition (no faradaic process so \({\it{\tilde z}}_{\rm{t}}\) becomes \({\it{c}}_{{\rm{dl}}}\) which is the pure capacitance of the double layer) along with the fit using the TLM represented in b, which allows the determination of \(\uptau _{\mathrm{e}}\). Here, since only the impedance of the single electrode is considered, the contribution of the ionic resistance from the separator is not represented in the TLM as well as does not appear in the EIS spectra. The dashed line is used to highlight the 45° slope of the medium frequency region.