Liquid water transport in a mixed-wet gas diffusion layer of a polymer electrolyte fuel cell

In this work, an accurate and computationally fast model for liquid water transport within a proton exchange membrane fuel cell (PEMFC) electrode is developed by lumping the space-dependence of the relevant variables. Capillarity is considered as the main transport mechanism within the gas diffusion layer (GDL). The novelty of the model lies in the simulation of the water transport at the interface between gas diffusion layer and gas flow channel (GFC). This is achieved with a phenomenological description of the process that allows its simulation with relative simplicity. Moreover, a detailed two-dimensional visualization of such interface is achieved via geometric simulation of water droplets formation, growth, coalescence and detachment on the surface of the GDL. The accomplishment of reduced computational time and good accuracy makes the model suitable for control strategy implementation to ensure PEM fuel cells operation within optimal electrode water content. Furthermore, the model is useful for optimization analysis oriented to both PEMFC design and balance of plant.

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Liquid Water Transport in Gas Diffusion Layer of Polymer Electrolyte Fuel Cells

Journal of The Electrochemical Society ◽

10.1149/1.1646148 ◽

2004 ◽

Vol 151 (3) ◽

pp. A399 ◽

Cited By ~ 443

Author(s):

Ugur Pasaogullari ◽

C. Y. Wang

Keyword(s):

Fuel Cells ◽

Polymer Electrolyte ◽

Water Transport ◽

Diffusion Layer ◽

Liquid Water ◽

Gas Diffusion Layer ◽

Gas Diffusion ◽

Polymer Electrolyte Fuel Cells ◽

Liquid Water Transport

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Modeling of Durability Effect on the Flooding Behavior in the PEFC Gas Diffusion Layer

ASME 2010 8th International Fuel Cell Science, Engineering and Technology Conference: Volume 1 ◽

10.1115/fuelcell2010-33241 ◽

2010 ◽

Cited By ~ 1

Author(s):

Partha P. Mukherjee ◽

Rangachary Mukundan ◽

Rodney L. Borup

Keyword(s):

Water Transport ◽

Diffusion Layer ◽

Liquid Water ◽

Critical Role ◽

Gas Diffusion Layer ◽

Gas Diffusion ◽

Polymer Electrolyte Fuel Cell ◽

Limiting Current ◽

Modeling Framework ◽

Liquid Water Transport

The gas diffusion layer (GDL) plays a critical role in the overall performance of a polymer electrolyte fuel cell (PEFC), especially in the mass transport control regime due to suboptimal liquid water transport. Liquid water blocks the porous pathways in the catalyst layer and gas diffusion layer thereby causing hindered oxygen transport from the channel to the active reaction sites. This phenomenon is known as “flooding” and is perceived as the primary mechanism leading to the limiting current behavior in the cell performance. The pore morphology and wetting characteristics of the cathode GDL are of paramount importance in the effective PEFC water management. Typical beginning-of-life GDLs exhibit hydrophobic characteristics, which facilities liquid water transport and hence reduces flooding. Experimental data, however, suggest that the GDL loses hydrophobicity over prolonged PEFC operation and becomes prone to enhanced flooding. In this work, we present a pore-scale modeling framework to study the structure-wettability-durability interplay in the context of flooding behavior in the PEFC GDL.

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