Use of X-ray computed tomography for understanding localised, along-the-channel degradation of polymer electrolyte fuel cells

Jennifer Hack, Lara Rasha, Patrick L. Cullen, Josh J. Bailey, Tobias P. Neville, Paul R. Shearing, Nigel P. Brandon, Dan J.L. Brett*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The need to understand the effects of degradation in polymer electrolyte fuel cells (PEFCs) has led to the development of in-situ and operando imaging studies of failure mechanisms occurring in their constituent materials, but studies using X-ray computed tomography (X-ray CT) for imaging have focussed primarily on a single region of the PEFC flow channel. Whilst studies have shown local variation in degradation rates using electrochemical techniques, this work employs identical-location X-ray CT imaging to elucidate the local degradation of a membrane electrode assembly (MEA) at various locations along-the-channel of a serpentine flow field. Using a carbon corrosion specific accelerated stress test (AST), in-depth analyses of the catalyst layers (CLs) and crack network allow for quantification of the material's degradation at the inlet, middle and outlet regions of the flow channel on the cathode side. Imaging of the regions was done after 0, 2000 and 5000 cycles and results show significant regional variation in the extent of degradation of the cathode CL. The order of degradation was found to be outlet > middle > inlet, with the outlet CL found to be thinner than the middle and inlet regions, with a greater extent of cracking. Furthermore, additional land and channel degradation effects were probed, with the land regions found to be less degraded than channel regions. This work further highlights the need to understand and develop ASTs that can promote a more uniform degradation rate across an MEA.

Original languageEnglish
Article number136464
JournalElectrochimica Acta
Volume352
Early online date23 May 2020
DOIs
Publication statusPublished - 20 Aug 2020
Externally publishedYes

Bibliographical note

Funding Information:
Jennifer Hack would like to acknowledge a studentship from the EPSRC Centre for Doctoral Training in Advanced Characterisation of Material (EP/LO15277/1) and fuel cell research in the Electrochemical Innovation Lab through (EP/S018204/2, EP/R023581/1, EP/P009050/1, EP/L015749/1, EP/M014371/1, EP/M023508/1, EP/M009394/1, EP/L014289/1, EP/K038656/1). PLC would like to thank EPSRC for its continued support (EP/S001298/1).

Funding Information:
Jennifer Hack would like to acknowledge a studentship from the EPSRC Centre for Doctoral Training in Advanced Characterisation of Material (EP/LO15277/1) and fuel cell research in the Electrochemical Innovation Lab through (EP/S018204/2, EP/R023581/1, EP/P009050/1, EP/L015749/1, EP/M014371/1, EP/M023508/1, EP/M009394/1, EP/L014289/1, EP/K038656/1). PLC would like to thank EPSRC for its continued support ( EP/S001298/1 ).

Publisher Copyright:
© 2020 Elsevier Ltd

Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.

Keywords

  • Accelerated stress test
  • Carbon corrosion
  • Local degradation
  • Membrane electrode assembly
  • Polymer electrolyte fuel cell
  • X-ray computed tomography

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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