Enhancement of water droplet drainage performance in a cathode flow channel with baffles for a polymer electrolyte membrane fuel cell

A reasonable design of flow channel is crucial for water management of a polymer electrolyte membrane fuel cell (PEMFC), and thus the cell performance. This paper develops newly designed baffles on a cathode flow channel to boost the water droplet drainage ability. The water droplet drainage characteristics within the novel flow channel are investigated by using a volume of fluid (VOF) method. The results show that the baffle height and number have a significant impact on the water droplet drainage performance. An appropriately increased baffle height and number leads to a shorter water droplet drainage time with a relatively low pressure drop. The water droplet drainage time for baffle height and number of 0.25 mm and 7 is reduced to 8.5 ms from 22.5 ms compared with that for the conventional channel. However, a too large baffle height and number could yield a very large pressure drop, thereby causing the water droplet detachment from the GDL surface and finally adsorption to the sidewalls. An optimal non-uniform interval layout of baffles along the channel can further shorten the water droplet drainage time by 6.25%. These findings can guide the optimal design of flow channels with baffles for a high-performance fuel cell.

Automated summary

A reasonable design of flow channel is crucial for enhancing the performance of a fuel cell. This paper introduces newly designed baffles on a cathode flow channel to improve water droplet drainage ability. The results show that increasing the baffle height and number can shorten water droplet drainage time and reduce pressure drop. Moreover, an optimal non-uniform layout of baffles along the channel can further enhance the drainage performance.