Evaluation of water distribution in a small-sized PEFC by neutron radiography

中性子ラジオグラフィによる小型燃料電池の水分布評価

安田 良; 塩澤 方浩*; 片桐 政樹*; 竹中 信幸*; 酒井 卓郎; 林田 洋寿; 松林 政仁  

Yasuda, Ryo; Shiozawa, Masahiro*; Katagiri, Masaki*; Takenaka, Nobuyuki*; Sakai, Takuro; Hayashida, Hirotoshi; Matsubayashi, Masahito

Neutron radiography is a useful tool for visualization of water distribution in fuel cells. In this study, we prepared a high spatial resolution neutron imaging system and small-sized fuel cell, and observed the through-plane water distribution in the fuel cell after operation. Fuel cell operations were carried out while varying the gas flow rate in the constant current mode. In low flow rate conditions, voltage decreased as operation time increased, and dropped below 0.2 V at 7.5 min. In neutron images obtained after fuel cell operation, water distribution was observed around the membrane electrode assembly (MEA) at the beginning of the operation and expanded over time to the gas diffusion layer (GDL) and channel on the cathode side. In higher flow rate conditions, fuel cell operation was more stable than in the low flow rate conditions. Neutron imaging results suggest that stable fuel cell operation is attributable to water discharge due to expulsion by the gas flow.