The behavior of the impedance in the samples with an AM content of 90 % and 92 % is very similar, clearly showing the transmission-line behavior for each porosity range. Interestingly, it can be observed that there is an RC behavior at high frequencies that shows a lower resistance as the porosity is reduced. This RC type shape can be ascribed to the presence of a contact resistance between the porous material and the current collector, as depicted by Pouraghajan et al. and mentioned in the methods section and reflected in equation ( ). This impedance is not merely in series with the transmission line in the EIS model used but embedded in the transmission line model as portrayed in equation (1). The use of this modified transmission line model allows a more accurate determination of the tortuosity factor in electrodes with a significant contact impedance, as it allows to completely disentangle the contributions from the transport along the pores (𝑹 𝒊𝒐𝒏 ) and through the current collectorelectrode interface (𝑹 𝒄𝒄 Based on this model, the behavior observed in Figure for the AM 90 % and 92 % can be interpreted as an improvement of the contact between current collector and electrode due to the compression occurred during calendering.