Reinforcing membranes with subgaskets in proton exchange membrane water electrolysis: A model-based analysis

Ensuring the long-term mechanical durability of perfluorosulfonic acid membranes in proton exchange membrane water electrolysis (PEMWE) is essential for long lifetimes. This study investigates the potential of reinforcing the membrane by incorporating a subgasket layer outside the active area. Thus, experimental tensile measurements with the subgasket material and with the subgasket-membrane composite are conducted to characterize their mechanical properties. The obtained data are used to identify suitable material models and parameterize them by applying a tensile test simulation based on the finite element method. By integrating subgaskets in a structural mechanics PEMWE cell model, the impact of the reinforcement on the membrane stability was investigated. The results indicate that even thin layers of subgaskets stabilize the membrane at the gap interface between the cell frame and the porous transport layer. The level of stabilization is further enhanced when using thicker subgaskets that cover the entire gap. However, one-sided subgaskets exhibit reduced mechanical stabilization. Furthermore, membrane buckling due to an increased gap size can be prevented using a subgasket up to a maximum gap size of 0.45 mm.