Experimental Study of Oxygen Transport Mechanisms in PEMFC Interdigitated Flow Field

• Published in: Journal of the Electrochemical Society Vol. 165; no. 16; pp. F1385 - F1391
• Main Authors: Tajiri, Kazuya, Karani, Jash, Shrivastava, Udit N.
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society 2018
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.0021902jes

Proton exchange membrane fuel cells for automotive application need to provide high performance at higher current density region where the oxygen transport is the limiting factor. Because of convective mass transport mechanism, interdigitated flow field has a potential to improve the oxygen transport limitation. In this paper, the mass transport mechanisms in an interdigitated flow field are experimentally studied using a segmented cell with 350 μm resolution in land-channel direction. At high current density operation, in general, the region under the land has higher values of local current density than regions under the channel which is opposite to a typical profile for conventional flow field. The local oxygen transport resistances measured at limiting current density conditions show the nearly constant values at lower oxygen concentration operation and then sudden increase at higher concentration. This indicates the presence of liquid water in the oxygen transport path when operated with high oxygen concentration. Convective-dominant and diffusive-dominant oxygen transport regions in gas diffusion layer (GDL) are identified from the oxygen transport resistance distribution, and the change of effective oxygen diffusivity in GDL due to liquid water is also estimated.