Inactive material and effective properties

[TomTranter]

From what I can tell we use the active material volume fraction and electrode porosity in the models to modify solid and electrolyte transport properties such as electronic and ionic conductivity. I understand active material to mean the particles that participate in reactions but these typically have very low electronic conductivity and there is inactive material (binder) that facilitates the electron transport. For thicker electrodes and with low binder fractions and/or high solid phase tortuosity this could become a limiting factor. I also believe there is no check on whether the electrode porosity and active material volume fraction sum to <= 1.0. I think inactive material properties such as electronic conductivity and tortuosity should be included in the models. Is there a reason we do not and instead use only the active material to conduct electrons when calculating solid potentials apart from simplicity?