In order to model the transport processes occurring in the electrode in the macro-scale, the porous electrode theory was employed. Porous electrode theory provides a macroscopic description of electrodes with co-existing solid and liquid phases . This approach disregards the geometric details of individual pores and instead employs volume-averaged conservation equations for fluid motion, species, and charge transport . Effective transport properties account for microstructural dependencies. The averaging process occurs over a representative volume element (RVE) as depicted in Fig. , which is large compared to pore size but small relative to regions with significant macroscopic variations . Porosity (ε) represents the ratio of void volume to total volume within the RVE. In the current study, the void volume was assumed to be entirely filled by the liquid phase, so the RVE is to be filled by the solid (Ω solid ) and fluid (Ω fluid ) regions: