Fig. 5: Comparison of two approaches using two numerically generated 3D microstructures.

Case A: microstructure with 2 µm particle size and ε = 35%. Case B: microstructure with 5 µm particle size and ε = 20%. For each case, a plot shows simulated EIS of eSCM along with the fit using Eq. 4. The high-frequency intercepts with real axis in both cases are different to zero, which represent the ionic resistances from the separator layer. Each plot contains an inset showing the resulting electrode tortuosity factor \(\uptau _{\mathrm{e}}\) and the corresponding symmetric cell configuration. The cross-section and the tortuosity factor \(\uptau\) of these microstructures given by the eRDM are also presented. The pore networks separated into through-pores and dead-end pores are shown. Here, only open pores (connected pores) that possess less than 2% (arbitrary threshold value) of the total flux density are considered as dead-end pores. The threshold value was set to take into account the dead-end pores having either no flux or low flux. The microstructure size in case A is 100 × 100 × 100 voxels, in case B is 50 × 50 × 50 voxels, and the voxel size is 250 nm.