Neutron is marvelous probe to see operating fuel cell

Putra, A.; Koizumi, Satoshi; Yamaguchi, Daisuke; Zhao, Y.; Noda, Yohei; Iwase, Hiroki*

In order to visualize water distribution in an operating fuel cell, we combined method of small-angle and ultra-small-angle scattering, SANS and radiography imaging. SANS observes water distribution in a membrane electrolyte assembly, MEA whereas radiography observes bulk water appeared in a gas flow channel called flooding. We employed hydrogen gas and deuterated gas as a fuel for operation. With exchange of H and D, we aim to perform a contrast variation as for polyelectrolyte film, Nafion. By changing a fuel gas from H to D, SANS quantitatively detected decrease of scattering intensity at scattering maximum originating from the ion-channel in the electrolyte. We found that 30 wt percent of the total water is replaced by D2O by changing the gas from H to D.