Measurement of water distribution in through-plane direction in a PEFC using a neutron image intensifier

Abstract

Hydrogen gas and air are supplied to a polymer electrolyte fuel cell (PEFC). The air and the hydrogen form water and condensation may occur in the cathode side. The generated water may affect the fuel cell performance because of blocking the oxygen from reaching cathode reaction area. An imaging system with a neutron image intensifier (NII) was used for visualizing the water behaviour in the PEFC. The water distributions in the proton exchange membrane (PEM) and the gas diffusion layers (GDL) were measured by the imaging system. Visualization experiments were performed during the PEFC operation in order to clarify the water distributions in the experiments with different utilization. The generated water was discharged into the channel after the amount of water thickness in the GDL increased to a certain value of about 600 μm in thickness in the through-plane direction. The discharged water formed water drops in the channel. The effects of the water drops in the channel on the fuel cell performance could be observed clearly. It was shown that the cell voltage increased when the water was evacuated. © 2013 The Authors.