PEMFC Performance with Metal Bipolar Plates Depending on the Channel Dimension

Abstract

Bipolar plates of a proton exchange membrane fuel cell (PEMFC) play an important role in removing liquid phase water as a by-product in order to facilitate the reaction between fuel and oxygen. A great amount of effort has been made to improve the performance of a fuel cell such as maximum current density or maximum power, by improving water removability of a bipolar plate. Most of the studies, however, are conducted numerically because of the complexity of analysing gas and liquid and the poor manufacturability of graphite bipolar plates. In this proceeding, we demonstrate that the performance of a PEMFC with metal bipolar plates can be enhanced by reducing the dimension of the channel. Bipolar plates were machined with stainless steel (type 316L) to have three different channel size (1000 um, 500 um and 300 um) and the performance of each assembled cells were tested. As a result, the maximum power density and the maximum current density increased by 25%.