Oxidation of metal bipolar plates in proton exchange membrane fuel cells leads to free metal radical deposition and overvoltage losses in the short term, but in the long term not only to degradation of the component itself, but also to interrelated degradation of other components via the Fenton mechanism. In the thesis, we develop a two-layer model of oxide layer growth based on the point defect model, linking the electrochemical conditions at the oxide boundary with the diffusion of defects in the chromium inner and iron outer layers. The model is parameterised and validated using experimental data to confirm the consistency of the evolution of oxide thickness and composition over time. The validated model confirms the key growth mechanisms and enables quantitative evaluation of the influence of fuel cell operating parameters on surface oxidation of bipolar plates.
|
