Water management capabilities of bio-inspired flow field configurations for polymer electrolyte membrane fuel cells

Fuel cells have received an increasing amount of attention over the past decade for their power production capabilities. Polymer electrolyte membrane (PEM) fuel cells in particular are researched because of their high power density, large range of operating conditions, green products, and ease of scalability. PEM fuel cells do have a number of issues that reduce their overall performance. These issues include variations in reactant distribution, materials issues for the bipolar plate, and flooding caused by poor water management. Variations in the reactant distribution causes lower overall power output due to regions of low reactant density. This means that optimizing the flow field to increase reactant density increases performance. One optimization method is to mimic natural structures that have similar functions. Leaves, lungs, and vein structures all have similar purposes to those in PEM fuel cells. Imitating their structure has been shown to improve power. It is also important to determine their water management properties. The membrane in the fuel cell must be hydrated to operate at optimally; however excess water causes mass transport issues by either blocking the channels or filling pores in the gas diffusion layer (GDL). This means that the water content in a PEM fuel cell must be delicately balanced to ensure that the membrane stays hydrated without causing flooding issues. Therefore, it is important to determine the water management capabilities of various bipolar plate designs. Clear bipolar plates are used to directly observe the water management capabilities of different flow field designs, which will be verified by the finite element model. These tests have shown that bio-inspired designs perform well in comparison with their conventional counterparts --Abstract, page iii