| Title: |
Understanding water dynamics in operating fuel cells by operando neutron tomography: investigation of different flow field designs |
| Authors: |
Hack, Jennifer; Ziesche, Ralf; Fransson, Matilda; Suter, Theo; Helfen, Lukas; Couture, Cyrille; Kardjilov, Nikolay; Tengattini, Alessandro; Shearing, Paul; Brett, Dan |
| Contributors: |
European Synchrotron Radiation Facility Grenoble (ESRF); Institut Laue-Langevin (ILL); GéoMécanique; Laboratoire sols, solides, structures - risques Grenoble (3SR); Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP); Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP); Université Grenoble Alpes (UGA); Helmholtz-Zentrum Berlin für Materialien und Energie GmbH = Helmholtz Centre Berlin for Materials and Energy = Centre Helmholtz de Berlin pour les matériaux et l'énergie (HZB); Helmholtz-Gemeinschaft = Helmholtz Association; Institut universitaire de France (IUF); Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.) |
| Source: |
ISSN: 2515-7655 ; Journal of physics ; https://hal.science/hal-04918051 ; Journal of physics, 2024, 6 (2), pp.025021. ⟨10.1088/2515-7655/ad3984⟩. |
| Publisher Information: |
CCSD; IOP publishing |
| Publication Year: |
2024 |
| Collection: |
Université Grenoble Alpes: HAL |
| Subject Terms: |
[SPI.GCIV]Engineering Sciences [physics]/Civil Engineering |
| Description: |
International audience ; Abstract Water management plays a key role in ensuring optimum polymer electrolyte fuel cell (PEFC) performance, and flow field design can influence the ability of a cell to balance maintaining hydration, whilst avoiding flooding and cell failure. This work deepens the understanding of water evolution in different PEFC flow channel designs, namely single serpentine (SS), double serpentine (DS) and parallel, using our novel high-speed neutron computed tomography method. We developed our previously-reported method by introducing continuous cell rotation, enabling 18 s per tomogram during 1 h holds at 300, 400 and 500 mA cm −2 . The volume of water evolved in the cathode, membrane electrode assembly and anode was quantified, and key mechanisms for water droplet formation in the different flow channel designs were elucidated. The parallel flow field design had the poorest water management, with 47% of the cathode flow channel becoming filled after 1 h at 400 mA cm −2 . This significant flooding blocked reactant sites and contributed to unstable cell performance and, ultimately, cell failure at higher current densities. The SS cell displayed the best water management, with only 11% of the cathode channel filled with water after 1 h at 500 mA cm −2 , compared with 28% of the DS cathode channel. 3D visualisation and analysis of droplet behaviour elucidated how water ‘slugs’ in the SS were removed in the gas stream, whereas three of the four parallel cathode flow channels became entirely filled with water plugs, blocking gas flow and exacerbating cell flooding. The new insights gained here are expected to extend to novel flow field designs and image-based models, with the use of operando neutron CT demonstrated as a powerful technique for both visualising and quantifying water management in operating PEFCs, as well as deepening the knowledge of droplet behaviour in different flow field types. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1088/2515-7655/ad3984 |
| Availability: |
https://hal.science/hal-04918051; https://hal.science/hal-04918051v1/document; https://hal.science/hal-04918051v1/file/Hack_2024_J._Phys._Energy_6_025021.pdf; https://doi.org/10.1088/2515-7655/ad3984 |
| Rights: |
info:eu-repo/semantics/OpenAccess |
| Accession Number: |
edsbas.A9604D61 |
| Database: |
BASE |