Modeling Mechanical Behavior of Membranes in Proton Exchange Membrane Water Electrolysis

The reliability of a proton exchange membrane water electrolysis (PEMWE) depends significantly on the long-term mechanical stability of the membrane due to its relatively low mechanical robustness . Membrane defects can be caused, for example, by severe mechanical stress in the critical gap between the cell frame and the porous transport layer (PTL). In this work the mechanical stresses and strains are quantified for such scenarios by using a finite element (FE) analysis which is applied to a simplified model setup. Nafion® is used as a standard material for the membrane and an appropriate material model is implemented into a FE software. The used parameters are based on and validated by experimental data from tensile tests to ensure matching with real PEMWE systems. The validated material model is used in the cell simulation to identify resulting stresses and strains during assembly and operation. In accordance with experimental experience, no critical states were identified. Furthermore, differential pressure up to 10 bar in the model could not cause any significant change compared to deformations resulting from boundary conditions for balanced pressure operation. Varying the gap size between the cell frame and PTL resulted in a buckling in the simulated membrane for sizes of 0.3 mm and more during membrane swelling.