In-situ observation inside an operating fuel cell by a combined method of small-angle neutron scattering and neutron radiography

Putra, A.; Koizumi, Satoshi; Yamaguchi, Daisuke; Iwase, Hiroki*; Maekawa, Yasunari; Matsubayashi, Masahito  ; Hashimoto, Takeji

In-situ observation to visualize water generated inside an operating polymer electrolyte fuel cell (PEFC) in a wide length scale from nanometer to millimeter has been done by a combined method of small-angle neutron scattering (SANS) and neutron radiography (NR). The NR apparatus composed of a scintillator, optical mirrors and a CCD camera, was installed at a sample position of the focusing and SANS spectrometer (SANS-J-II) at research reactor JRR-3 in Japan Atomic Energy Agency, Tokai, Japan. This new method succeeded in detecting a spatial distribution of the water generated in individual cell elements; NR detected the water in a gas diffusion layer and a flow-field, whereas SANS quantitatively determines the water content in a membrane electrode assembly (MEA).