Résumé
The objective of the proposed experiments is to use high energy X-ray diffraction to tackle the crucial question of the water distribution in anion exchange membrane fuel cells (AEMFC). Compared to other classically used techniques such as neutron or X-ray radiography, diffraction experiments are expected to reveal the water distribution dynamics in the various fuel cell components during transient regimes with an unprecedented temporal resolution. In particular, water gradients across the membrane electrode assembly (MEA) will be interpreted in light of a mathematical model for AEMFCs to confirm or refute the hypothesis of a critical slow step in water transfer from the polymer phase to the gas phase, suggested by our previous studies.