## 3 Results and Discussion
### Mercury Intrusion Porosimetry and N\({}_{2}\)-Physisorption
As with the MIP, the PSD showed an increasing pore volume below a 100 nm pore size for low porosity  
Figure 6: N\({}_{2}\)-physisorption: (**a**) linear adsorption isotherms for different porosities; increase of the specific surface areas with lower porosity; (**b**) specific surface area \(\sigma_{\text{BET}}\) using the BET method in relation to electrode porosity in the relative pressure range (p/p\({}^{\circ}\)) 0.05–0.15 (BET constant C: \(\approx\)70–100). Linear increase in \(\sigma_{BET}\) with lower porosity; (**c**) PSD calculated with the BjH method of the desorption branch of the isotherm. There was a larger hysteresis (inserted graph) for lower porosity, which resulted in more mesopores. PSD from the MIP of an electrode with 18% porosity is depicted by the dotted line and shows the same trend as the PSD from the physisorption experiment. electrodes. The shape of the PSD curves was comparable to the MIP experiments in the respective pore size range (Figure 6c; MIP shown as dotted line for 18% porosity). Therefore, it can be concluded that both methods are suitable for the analysis of LIB electrodes. At a pore size of 100 nm, when the BJH model reaches its limit of validity, a slightly larger pore volume for MIP can be identified. The desorption branch of the isotherm mostly describes the size of pore throats, such as those in MIP, but N\({}_{2}\)-physisorption is less affected by pore shielding or comparable errors. In this case, the higher pore volume measured with MIP at pore sizes of approximately 100 nm could be explained by a shift in the PSD to smaller values, since larger pores are blocked from the intruding Hg by a barrier of pores with smaller pore diameters \(\approx\) 100 nm as shown in Figure 5c. Quantifying the micropore volume is not possible with the BJH model but with a discrete Fourier transform calculation [14]. However, due to the high complexity of the pore network and its heterogeneity, there is no simple model to describe the whole pore structure ranging from micro- to macropores with different pore shapes. Considering the real electrode pore system in an LIB filled with electrolytes, micropore volume may not be crucial for a good electrochemical performance. [PERSON] et al. showed the influence of micropores on the performance of electrochemical double-layer capacitors [51]. Therein, it was stated that below a 1.8 nm pore size, the solvated Li-ions start to change their coordination in a standard electrolyte (1 M LiPF6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC), EC:EMC 50:50 wt%). In addition, PF\({}_{6}\) ions were desolvated in micropores smaller than 1.4 nm and kinetics for the ion transport slows down. Thus, especially for fast charging/discharging in LIBs, micropores could be inactive in terms of Li-ion transportation. Considering other battery systems, such as solid-state batteries, micropores and small mesopores can have a detrimental effect, because they hinder Li-ion mobility due to the nonconductive gaps between the solid electrolyte and/or AM particles. The accuracy of N\({}_{2}\)-physisorption was illustrated by the electrode with 30% total porosity and the reference electrode (\(\epsilon=28\%\)). No variance between the two porosities could be identified for the linear isotherm and the PSD. The difference in the two \(\sigma_{\text{BET}}\) was 2%. Considering the systematic error of the device (e.g., the accuracy of pressure reading) and the limitations of the experimental setup (e.g., a limited sample space in tube), a realistic inaccuracy for the adsorbed quantity and the surface area was up to 5-10%. Therefore, the deviation for the BET results (\(\epsilon=30\%\) compared to \(\epsilon=28\%\)) was negligible and the micropore volume was in the range of the variance of the pressure reading. For samples with a small specific surface area, changing the analysis gas to krypton could lead to more accurate results due to the higher sensitivity [14].