Lattice Boltzmann Methods for Simulating Multiphase Flow in Proton Exchange Membrane Electrolyzers and Drying of Porous Media: A Review and Outlook

Efficient management of multiphase transport in porous media underpins the performance and durability of fuel cells, electrolyzers, and batteries. These devices are governed by pore-scale phenomena (capillary dynamics, interfacial forces, and microstructural heterogeneity) that control drying of catalyst supports, electrolyte distribution and evaporation, and phase change in cooling pathways. As architectures shift toward mesoscopic porous structures, predictive models must resolve interfacial motion and topology in complex geometries while remaining computationally viable. The lattice Boltzmann method (LBM) has emerged as a versatile framework: its discrete formulation naturally captures interfacial effects without explicit interface tracking and accommodates complex boundaries. This review examines the state of the art in LBM-based modeling of multiphase flow in mesoscale porous media, with emphasis on two systems, (i) drying of porous media and (ii) multiphase transport in electrolyzer components, and on coupled LBM approaches for solute and heat transfer. We critically assess implementation methodologies, highlighting advances, limitations, and outstanding challenges, and evaluate strategies for coupling scalar transport with fluid flow to analyze solute and thermal phenomena. Drawing on key studies, we identify priorities for future development and outline a roadmap for leveraging LBM as a high-performance tool for the design and optimization of next-generation energy materials and devices.