Cold-start of parallel and interdigitated flow-field polymer electrolyte membrane fuel cell

Achieving cold-start of polymer electrolyte membrane fuel cells (PEMFCs) from temperatures less than or equal to 0 degrees C can be a challenge due to the freezing of byproduct water in the cathode catalyst layer (CCL). The ability to remove water from the CCL at a rate that prevents flooding until the cell reaches temperatures above the freezing point is critical, however, they are made difficult by the low saturation pressure of air gasses below 0 degrees C. Under less extreme cold-start conditions (-10 degrees C to 0 degrees C) the water uptake of air can be considered non-negligible for specific flow rates and flow-field designs. Interdigitated flow-fields induce convective transport through the gas diffusion layer (GDL) and CCL under land areas, called cross flow, and have been shown to have enhanced water removal from under lands compared with parallel flow-fields. This study compares the cold-start performance between a parallel and interdigitated flow-field PEMFCs at various current densities. Testing of cold-start in an environmental chamber at -4 degrees C, -6 degrees C and -8 degrees C at current densities of 200 mA cm(-2) and 400 mA cm(-2) using galvanostatic control was completed. Results show that an interdigitated flow-field may provide better performance under less extreme cold-start conditions than parallel flow fields. (C) 2013 Elsevier Ltd. All rights reserved.