The Effects of Channel Depths on the Performance of Proton Exchange Membrane Fuel Cells with Metallic Bipolar Plates

摘要

The flow channels on bipolar plates distribute fuels to the surface of membrane electrode assembly (MEA). The geometry and design of flow channels have strong effects on the cell performance. This study fabricates the metallic bipolar plates using die-sinking micro electrical discharge. The SUS316L stainless steel is selected as the plate material. The flow field is a three-pass serpentine structure, of which both the rib and channel widths are 500μm and the channel depths are varied as 200, 400 and 600μm, in a reaction area of 4cm~2. During the test, this study assemblies a cell with the carbon-paper MEA. The performance of the cell is evaluated based on three different channel depths with varying anode flow rates. The results indicate that the cell performance is slightly influenced by the channel depths. The cell with channel depth of 400μm yields best results. For the deep channel depth (600μm), the gas pressure is relatively low and the fuel is distributed less effectively to the entire reaction area. For the shallow channel depth (200μm), the efficiency of mass transport is relatively poor. Both cases lower the performance of the fuel cell.