Unveiling OER bubble dynamics in alkaline electrolysis: Impacts on cell resistance

Abstract

Alkaline electrolysis is a promising technology for large-scale hydrogen production, though its efficiency is significantly affected by the formation and behavior of gas bubbles on the electrode surfaces. This study combines experimental analysis with computational modeling to investigate the impact of bubble dynamics on OER reaction and overall cell performance. By employing Electrochemical Impedance Spectroscopy (EIS), we analyze the relationship between bubble formation and the increase in ohmic resistance at low-medium current densities in 2 M KOH solution, revealing how bubbles obstruct ion conduction pathways. By integrating experimental data with model predictions, this work provides critical insight to improve predictions of polarization curve behavior by taking into account additional bubble-induced resistances under operational conditions for alkaline electrolyzers.