12. Fuel Cells and Battery Technology

Electrochemical energy devices, such as secondary batteries and fuel cells, play a pivotal role in bridging the intermittent nature of renewable energy resources by providing reliable and efficient means for both energy conversion and storage. Nevertheless, their performance requires further enhancement before achieving widespread commercial adoption. Improving the performance of an electrochemical cell entails designing and fabricating optimized electrode structures that strike a proper balance among various physical phenomena. Mathematical modeling and optimization can be employed to develop electrodes with tailored structures through a systematic approach. However, previous studies have primarily focused on optimizing volume-averaged (macroscopic) properties, such as porosity. Achieving finely tuned design solutions requires the integration of mathematical optimization methods with a pore-scale modeling framework that accounts for the influence of microstructures on reactive transport. Among various pore-scale modeling approaches, a feasible solution is to adopt a pore network model (PNM), which is less computationally demanding. In this study, a binary genetic algorithm (GA) is employed to determine the existence or nonexistence of potential pores in a background grid with the goal of maximizing the overall reaction rate. Each solution is encoded as a Boolean vector, indicating the existence or absence of candidate pores within a predefined grid. Deleting a pore allows neighboring pores to expand, enhancing the transport of reactant materials; however, this also reduces the reactive surface area. A proof-of-concept study was carried out on a 3D grid with a dimension scale of millimeters and a pore resolution of tens of microns. The optimizer generated a set of Pareto optimal porous reactors, offering higher conversion rates and lower pumping costs due to their superior pore network configurations that led to higher reactive surface area and permeability. This approach paves the way for designing high-performance electrodes for electrochemical energy devices.