A Study of dynamic characteristics of PEM fuel cells by measuring local currents

Dynamic characteristics are important information in analyzing and understanding PEM fuel cell performances and detailed local dynamic information is extremely important in the understanding of fundamental mechanisms. In this study, the input parameters studied include humidification temperature of the reactant gases, operating temperature, and operating backpressure and the local dynamic responses are the local current densities. The fuel cell used is a PEM fuel cell with a single channel serpentine flow field and the local current densities are directly measured using the current density distribution measurement gasket and a multi-channel potentiostat. The experimental results show that very different local dynamic responses exist even though the response of the average current shows very little dynamics. Especially when the humidification temperature increases from a low value to moderate value, the responses of the local current density in the upstream are very different from those in the downstream.