Bubble dynamics matters at high-rate water electrolysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41633997.
- Also identified by DOI 10.1038/s41467-026-69052-5 and PMC identifier 12976329.
- Licence recorded as CC BY-NC-ND.
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Abstract
Bubbles accumulation in the electrode limits anion exchange membrane water electrolyzer performance at industrial current densities (>1.0 A cm<sup>-2</sup>). Currently, conventional electrode designs prioritize the optimization of the electrochemically active surface area. However, this study reveals that bubble dynamics matters high-rate water electrolysis efficiency in anode-feeding mode in three ways:1) cover active sites at the anode; 2) hinder water diffusion through the membrane; 3) cause water shortage at the cathode. Based on this mechanism, we propose an easy-to-prepare gradient stainless steel square hole mesh electrode. It not only offers a low cost ($8-150/m<sup>2</sup>), but also improves bubble dynamics. As a result, it reduces the cell voltage by 0.14 V at a current density of 5.0 A cm<sup>-2</sup>, even with a lower electrochemically active surface area compared to the stainless steel felt electrode. And it maintains a stable operation over 400 hours. This work redefines electrode engineering paradigms, shifting focus from electrochemically active surface area-centric approaches to two-phase flow management in water electrolyzers for industrial current densities-scale hydrogen production.