%0 Journal Article
%@ 2158-3226
%A Koizumi, Satoshi
%A Ueda, Satoru
%A Ananda, Putra
%A Tsutsumi, Yasuyuki
%A Laboratory of Living Soft Matter, Institute of Quantum Beam Science, Ibaraki University, Shirakata, Ibaraki, Japan,
%A Laboratory of Living Soft Matter, Institute of Quantum Beam Science, Ibaraki University, Shirakata, Ibaraki, Japan,
%A FMIPA UNP,
%A FC Development, Co., Ltd., Ibaraki University, Nakanarusawa, Hitachi, Ibaraki, Japan,
%D 2019
%F repounp:38681
%I AIP Publishing
%J AIP Advances
%K Polymer electrolyte fuel cell, heterogeneous performance, respiration mode, non-equilibrium phenomenon, small-angle neutron scattering, water flooding, Nafion membrane
%N 6
%P 1-9
%T Heterogeneous Cell Performance of Polymer Electrolyte Fuel Cell at High Current Operation: Respiration Mode as Non-Equilibrium Phenomenon
%U https://repository.unp.ac.id/id/eprint/38681/
%V 9
%X The heterogeneous performance of polymer electrolyte fuel cell in space and time was discussed for operation at high current density. The cell voltage, detected by a segmented electrode, varies along a gas flow channel from upper to bottom stream and oscillates in time, which is referred as a respiration mode. At the higher current, the cell voltage at different positions started to be synchronized, as the current density increases. In order to investigate a role of water on the respiration, we employed a new method of contrast variation for small-angle neutron scattering (SANS) using deuterium (D2) gas as a fuel. By using D2, we introduce special scattering contrast in a polymer electrolyte film (Nafion®), when the film is originally swollen by H2O. After switching from H2 to D2 gas (humidified with H2O), we found that SANS intensity significantly decreases about 40% at the q-position of scattering maximum (qm) originating from the water-microdomains in the polymer electrolyte. After quantitative analyses of the scattering intensity, it was elucidated that 20 wt% of the total water is occupied by D2O as a steady state. At around the average intensity, SANS intensity oscillates with a time interval ∼100sec, which corresponds to the respiration mode found for voltage. The respiration behavior is considered as a non-linear & non-equilibrium phenomenon in an open system, where water flooding plays a role of feedback to decelerate fuel transportation and chemical reaction of water generation.