POS6-0274
Accurate evaluation of hydrogen crossover in water electrolysis systems: Elucidating ion channel morphology for hydrated membranes
Topic
S6. Emerging Polymer and Hybrid Materials for Advanced Energy Storage and Conversion
When and Where
Sep 29, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Hae Jung SON
Boseok KANG
Presenter(s)
Seung Hwan Kim (Kyung Hee University)
Co-Author(s)
Abstract
Rigorous management of hydrogen crossover is critical for the safety and efficiency of polymer electrolyte membrane water electrolysis. We investigated the pressure decay method to accurately characterize hydrogen crossover through dry and hydrated membranes in water electrolysis systems. A precise structural analysis is essential because gas permeation is fundamentally governed by the connectivity of internal ion channels. However, static characterization methods fail to capture the dynamic morphology of water-swollen membranes governing gas permeation. This work establishes a quantitative framework using in-situ hydrogen crossover data as a morphological probe to characterize the effective ion channel architecture of fully hydrated membranes. Integrating direction-dependent swelling with gas transport models, we elucidate the functional morphology and intrinsic ion channel connectivity. Applying this platform to sulfonated poly(arylene ether sulfone) (BPSH), we demonstrate how performance distinctly varies between random and multi-block copolymerized structures. Random BPSH copolymers exhibit isotropic swelling and isolated dead-end domains (tortuosity ~6.8), whereas multi-block BPSH architectures form anisotropically stable, interconnected networks (tortuosity ~3.9). This structural shift overcomes the conventional conductivity-crossover trade-off, achieving enhanced ion conductivity without proportionate increase in gas crossover. Ultimately, this methodology provides quantitative parameters to manage gas crossover and guide the design of next-generation polymer electrolyte membranes.
