Investigating bubble-induced overpotential, current non-uniformity, and bubble distribution in flow-based water electrolyzers: A numerical study

The transition towards a sustainable energy landscape necessitates efficient and scalable technologies for
renewable energy storage. Water electrolysis, a process that converts electrical energy into chemical energy
stored in hydrogen, holds immense potential for integration with intermittent renewable sources. However, the
performance and efficiency of water electrolyzers are impeded by the complex multiphase flow dynamics
involving bubble nucleation, growth, and transport within the electrochemical cell. This study employs state-of-
the-art three-dimensional multiphase flow simulations to unravel the intricate interplay between bubbles and the
electrochemical processes in a parallel-electrodes flow-based electrolyzer (PE-FBE). By accurately capturing
bubble-electrolyte interfaces, the simulations quantify the detrimental effects of bubbles on overpotentials,
current density distribution, and bubble distribution. Crucially, the impact of critical parameters, including flow
rate, bubble nucleation size, surfactant addition, and applied current, on these performance metrics is system-
atically investigated. The findings reveal strategies to mitigate bubble-induced losses, enhance current unifor-
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mity, and improve hydrogen purity, paving the way for optimized electrolyzer designs and efficient renewable
energy storage.