The dried electrode porosity (ε) is calculated by adding the number of pores voxels and a fraction of the number of CBD voxels, to account for the micropores that it contains, and normalize it to the total number of voxels. Then, according to the MacMullin number and since we consider the diffusion coefficient within the pores equal to 1, the tortuosity factor (τ) is determined by the ratio between the porosity and the effective diffusivity value (τ = ε / Deff).