Computational multi-physics modeling of membranes in proton exchange membrane water electrolyzers

The present work provides a modeling framework to capture the complex multi-physics electrochemical-hydro-mechanical processes in membranes of multilayer Proton Exchange Membrane Water Electrolysis (PEMWE) cells. It relies on the Theory of Porous Media (TPM) to establish a continuum-based framework suitable for efficient simulation of the coupled interactions of porous multiphase materials. This macroscopic framework is capable of accurately representing the local interactions among the immiscible phases, including membrane deformation, water transport, nanopore pressure dynamics, and proton diffusion, all of which are essential for PEMWE functionality. Numerical simulations in two-and three-dimensional space are presented to verify the capabilities of the model and to address key numerical stability challenges of the strongly coupled problem. The numerical implementations are carried out using the open-access finite element package FEniCSx. The corresponding source codes are openly available at[https://doi.org/10.25835/5s3p3a8s], allowing reproducibility by interested researchers.