Current Density Distribution in the Lateral Direction of Conventional and Interdigitated Flow Field

Abstract

The design of flow field significantly affects the mass transport in an operating PEMFC. One example of such design is interdigitated flow field. In this kind of flow field depending on the location both convective and diffusive mass transfer occur in the land-channel direction. These two modes of mass transfer influence the local current and water generation in the land-channel direction. To understand the difference between these two mass transport mechanism the comparison of local current density and ohmic resistance distribution in the land-channel direction of conventional and interdigitated flow fields is imperative. This work is focused on measurement of current density and ohmic resistance distribution in the land-channel direction of a conventional and an interdigitated flow fields. A customized catalyst coated membrane of active area 9 mm2 was prepared and a segmented anode was employed to measure the parameters mentioned at 350 µm resolution in the land-channel direction of an interdigitated flow field. At 60 oC and 90 % RH current density and ohmic resistance distribution were measured for both kind of flow fields, and discussion is presented.