Visualization and Measurement of Dynamic Water Behavior in Polymer Electrolyte Fuel Cell by Neutron Radiography

Abstract

Visualization of water behavior in a polymer electrolyte fuel cell was conducted by neutron radiography. Real-time video images and high-resolution still images were photographed with measurement of fuel cell generation performance. It was clearly visualized by real time imaging that water condensed in an air supply line was coming into a fuel cell. In this case the cell voltage decreased when water flowed into the cathode side. On the other hand, no effect of condensed water into the anode side was observed on the cell performance. In the results of high intensity still imaging, water amount in gas diffusion layer (GDL) under ribs and channel part with GDL were measured quantitatively. The oxygen utilization was varied while PEFC was in a constant current operation. Water amount in the GDL under ribs increased, and cell voltage decreased with increasing oxygen utilization. It can be said that water amount in the PEFC might strongly depend on airflow rate, and the cell voltage might be affected by the water amount.