Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells

Abstract Polymer electrolyte fuel cells (PEFCs) face significant challenges during cold starts, where water phase transitions affect critically fuel cell performance. While previous studies have primarily focused on ice formation and melting behavior, the impact of water condensation after breaking...

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Main Authors: Wataru Yoshimune, Satoshi Yamaguchi, Akihiko Kato, Yoriko Matsuoka, Satoru Kato
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
Online Access:https://doi.org/10.1038/s41598-025-08939-7
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author Wataru Yoshimune
Satoshi Yamaguchi
Akihiko Kato
Yoriko Matsuoka
Satoru Kato
author_facet Wataru Yoshimune
Satoshi Yamaguchi
Akihiko Kato
Yoriko Matsuoka
Satoru Kato
author_sort Wataru Yoshimune
collection DOAJ
description Abstract Polymer electrolyte fuel cells (PEFCs) face significant challenges during cold starts, where water phase transitions affect critically fuel cell performance. While previous studies have primarily focused on ice formation and melting behavior, the impact of water condensation after breaking through the freezing point remains insufficiently understood. In this study, we apply operando synchrotron X-ray computed tomography to visualize the transient water behavior in a PEFC under three different relative humidity (RH) conditions during a heating/cooling cycle simulating real-world cold-start conditions. The results revealed localized water flooding and hysteresis during the heating/cooling phase. A quantitative layer-by-layer analysis shows that water accumulation in each component layer strongly depends on both RH and the thermal cycle process. Moderate RH conditions promote efficient vapor-phase transport and minimize water flooding while avoiding membrane dehydration. These findings highlight water condensation as a key factor influencing cold-start performance and provide new insights into water management for more robust cold-start strategies toward next-generation PEFC systems.
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institution Kabale University
issn 2045-2322
language English
publishDate 2025-07-01
publisher Nature Portfolio
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spelling doaj-art-e36e9afc9bd04f17bc968eb7ce1a7d5b2025-08-20T03:37:20ZengNature PortfolioScientific Reports2045-23222025-07-011511910.1038/s41598-025-08939-7Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cellsWataru Yoshimune0Satoshi Yamaguchi1Akihiko Kato2Yoriko Matsuoka3Satoru Kato4Toyota Central R&D Labs., Inc.Toyota Central R&D Labs., Inc.Toyota Central R&D Labs., Inc.Toyota Central R&D Labs., Inc.Toyota Central R&D Labs., Inc.Abstract Polymer electrolyte fuel cells (PEFCs) face significant challenges during cold starts, where water phase transitions affect critically fuel cell performance. While previous studies have primarily focused on ice formation and melting behavior, the impact of water condensation after breaking through the freezing point remains insufficiently understood. In this study, we apply operando synchrotron X-ray computed tomography to visualize the transient water behavior in a PEFC under three different relative humidity (RH) conditions during a heating/cooling cycle simulating real-world cold-start conditions. The results revealed localized water flooding and hysteresis during the heating/cooling phase. A quantitative layer-by-layer analysis shows that water accumulation in each component layer strongly depends on both RH and the thermal cycle process. Moderate RH conditions promote efficient vapor-phase transport and minimize water flooding while avoiding membrane dehydration. These findings highlight water condensation as a key factor influencing cold-start performance and provide new insights into water management for more robust cold-start strategies toward next-generation PEFC systems.https://doi.org/10.1038/s41598-025-08939-7
spellingShingle Wataru Yoshimune
Satoshi Yamaguchi
Akihiko Kato
Yoriko Matsuoka
Satoru Kato
Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
Scientific Reports
title Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
title_full Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
title_fullStr Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
title_full_unstemmed Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
title_short Operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
title_sort operando visualization of water distribution hysteresis under temperature cycling in polymer electrolyte fuel cells
url https://doi.org/10.1038/s41598-025-08939-7
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