Cell-construction-dependent predictive modelling of gas supersaturation in PEM electrolyzers governing corresponding crossover and electrochemical effects

The permeation of hydrogen and oxygen through the membrane of PEM electrolyzers is an important topic regarding plant safety, efficiency and possible operation strategies. The possibility to predict these permeation fluxes purely from cell construction data would speed up electrolyzer development and decrease its cost. The present paper presents a semiempirical 0D model to predict the gas supersaturation governing those permeation processes and related overpotentials. Only measurable material quantities are used as input and necessary sub-models and material parameters were taken from literature. As a consequence, no further fitting to measurements is required. The proposed model allows for the comparison of arbitrary constructions and operating strategies to identify their optimum combination. It can also be used in long term operation simulations and for catalyst performance analysis. In addition, a new explanatory approach for non-linear behaviour of gas crossover is provided.