where 𝐽, 𝜎 and ∇𝜙 are the electrical flux density, the electrical conductivity and the potential gradient, respectively. In the resistor network model proposed in this work we make use of these fundamental equations by applying a virtual gradient to the voxel representations of our composite electrodes, compute the steady states and derive effective transport properties. The workflow can be described as follows (detailed description in Section S1 of the Supporting Information): First, a microstructure consisting of 300 x 300 x 300 cubic voxels is constructed.