being formulated in the optimization framework, where they are coupled by the mutual design variable γ. As indicated by cases with negative performance metrics in Fig. , the electrochemical power can decrease due to the modification made by the optimization of the flow pathway. However, for these results, the optimization algorithm has already tried to decrease the electrical loss as much as possible by forming conductive channels in competition with the fluid flow transport trying to find the easiest pathway to the exit to reduce the power dissipation. For a better understanding of this phenomenon, it is more beneficial to look at the convergence history of the optimization process as depicted in Fig. . The demonstrated cases were in the linear Butler-Volmer regime (δ = 1.0 and λ = 0.1) and Da = 10 -5 . The liquid/solid conductivity ratio (τ ) was set to 0.5 and 0.005 for the case (A) and (B) in Fig. , respectively.