Optimizing shunt currents and pressure drop in bipolar alkaline electrolysers

This is the authors' abstract. We don't add key points for this paper.

In alkaline electrolyzer stacks, mitigating shunt currents must be balanced against negative effects of pressure drop across flow compartments, as excessive pressure differences can compromise the operational safety. In particular, pressure differences between cathodic and anodic compartments can promote convective gas crossover. This work proposes a multiphysics model, derived from equivalent-circuit analysis, to simultaneously predict shunt currents, electrolyte flow distribution, and pressure drops in stack configurations with internal and external manifolds. The model couples voltage and pressure-drop calculations to evaluate the trade-off between Faradaic efficiency and the cathode-to-anode pressure difference (CTA(Formula presented)). Model predictions show good agreement with state-of-the-art studies. Comparisons between traditional and modern electrolyzer designs indicate typical shunt-current losses of 1%–2% under nominal load. It is shown that the manifold size constrains the extent of shunt currents, whereas the inlet-flow configuration strongly influences CTA(Formula presented) and flow uniformity across cells. A metaheuristic optimization algorithm shows that longer inlet channels combined with wider outlet compartments provide the best trade-off between Faradaic efficiency and operational safety.