The main objective when design flow fields is balancing the pressure drop and the amount of gas that is distributed to the GDL and catalyst layers. Parallel, serpentine and interdigitated designs are the most popular for fuel cell channels. In relatively small fuel cells, the serpentine design is usually used because the hydrogen reaction is not rate limiting and water blockage in the humidified anode can happen. In the image below, you can see a serpentine flow field design. The flow path is continuous and relatively efficient in distributing gas across the fuel cell. However, since the path is longer than in other designs, pressure loss might be a problem. One advantage of the design if that a block in the path does not compromise activity downstream. A disadvantage is that more gas needs to be input into the fuel cell because the design favors the depletion of the components. Another disadvantage is the build up of water in the cathode during extended periods of operation of ...
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