The Influence of Rib and Porous Reactor Thickness on Topologically Optimized Structure in Reaction-Diffusion Systems

The commercially available electrode used in electrochemical energy devices possesses a uniformly distributed porous structure. However, recent research has indicated that a non-uniform distribution of porosity can enhance the performance of these systems by facilitating mass transport. Topology optimization has emerged as an effective approach for optimizing the porous structure of electrodes, leading to the production of high-performance electrodes. Previously, topology optimization was employed to design porosity distributions in reaction-diffusion systems with a 1D nature, using various dimensional models. It was found that higher design dimensionality than one improves system performance by minimizing entropy generation. However, the performance gap between 2D and 3D designs was found to be relatively low. It was hypothesized that due to the 1D nature of the problem, a 2D model was sufficient to significantly enhance performance. To address this issue, this study focuses on a system geometry with a 2D nature, considering the influence of rib structures and electrode thickness. The density-based topology optimization method implemented in COMSOL Multiphysics was employed to solve the optimization problem. The results revealed that, in the optimized porosity distribution, the diagonal channels were formed in a system exhibited 2D nature. Interestingly, increasing the dimensionality of the system model beyond its inherent nature did not significantly impact the reaction rate within the system. However, it is worth noting that there may be certain conditions that warrant further exploration.