Improvement of under‐the‐rib oxygen concentration and water removal in proton exchange membrane fuel cells through three‐dimensional metal printed novel flow fields

Abstract

The porous electrode under the rib area suffers from lower local oxygen concentration and more severe water flooding than that under the channel, which significantly affect the performance of proton exchange membrane fuel cells. To improve the oxygen concentration and water drainage under the rib, a series of novel flow fields with auxiliary channels equipped with through-plane arrayed holes were manufactured by three-dimensional (3D) metal printing, and the cell performance, ohmic resistance and pressure drop were experimentally and numerically studied, respectively. The novel fields were based on the sophisticated modification of traditional serpentine and parallel flow fields, that significantly improved the cell performance at high current density with an optimal number or length of the auxiliary channels, owing to the trade-off between the electric resistance and mass transfer under the rib. This novel flow field design solved the trilemma of performance, pressure drop and manufacture feasibility through the implementation of 3D printing technology.

Review of Flow Field Designs for Polymer Electrolyte Membrane Fuel Cells

“…Reasonably increasing the sub-inlet flow upstream could further benefit the maximum power density while maintaining the uniformity of oxygen distribution, as shown in Figure 18. Parallel flow field designs suffer from serious water flooding under the rib, but a new type of parallel flow field design with an auxiliary channel under the ribs has been proposed to effectively resolve this problem [94][95][96][97][98]. Wang et al [95] deployed auxiliary channels in partially hollow ribs and drilled a series of arranged holes in the auxiliary channels, as shown in Figure 19.…”

Liquid water discharge capability enhancement of hierarchical pore structure in metal foam flow field of proton exchange membrane fuel cell

“…4 Moreover, a welldesigned flow field plate structure can effectively prevent water flooding, homogenize reactant gas distribution, and improve the durability and performance of PEM fuel cell. 5 Therefore, the structure design of flow field is considered an essential aspect of developing fuel-cell-based power systems for automobiles.…”

“…To further enhance mass transport and water removal processes, many researchers developed various flow fields based on channel‐rib structure, such as S‐shaped, 9 M‐like, 10 and Z‐shaped 11 flow fields, which can promote the overall cell performance of PEM fuel cell. However, the water flooding issue is prone to occur because conventional channel‐rib flow field increases the transport path of produced water 5 . Moreover, the channel‐rib structure also causes gas maldistribution in flow field to a large extent 12 .…”

“…However, the water flooding issue is prone to occur because conventional channel-rib flow field increases the transport path of produced water. 5 Moreover, the channel-rib structure also causes gas maldistribution in flow field to a large extent. 12 Thus, there is a pressing need to develop a new flow field structure that ensures uniform reactant gas distribution and efficient water removal.…”

“…One of the most critical components of PEM fuel cell is the flow field plate, or bipolar plate, which makes up over 60% of its weight and ~30% of its cost 4 . Moreover, a well‐designed flow field plate structure can effectively prevent water flooding, homogenize reactant gas distribution, and improve the durability and performance of PEM fuel cell 5 . Therefore, the structure design of flow field is considered an essential aspect of developing fuel‐cell‐based power systems for automobiles.…”