Measurement of capillary pressure in fuel cell diffusion media, micro-porous layers, catalyst layers, and interfaces

JOURNAL OF POWER SOURCES

卷:271

Article

LaManna, Jacob M.¹  Bothe, James V., Jr.¹  Zhang, Feng Yuan²  Mench, Matthew M.^1,3 

[1] Univ Tennessee, Dept Mech Aerosp & Biomed Engn, Knoxville, TN 37996 USA

[2] Univ Tennessee, Dept Mech Aerosp & Biomed Engn, Inst Space, Tullahoma, TN 37388 USA

[3] Oak Ridge Natl Lab, Energy & Transportat Sci Div, Oak Ridge, TN 37931 USA

关键词: Leverett;    Polymer electrolyte fuel cell;    Saturation;    Flooding;    Capillary;    Water management;   

DOI  :  10.1016/j.jpowsour.2014.07.163

来源: Elsevier

【 摘 要 】

In this work, semi-empirical Leverett J-Function relationships relating capillary pressure and water saturation are experimentally derived for commercial and experimental polymer electrolyte fuel cell materials developed for automotive applications. Relationships were derived for Mitsubishi Rayon Corp. (MRC) U105 and General Motors (GM) experimental high tortuosity diffusion media (DM), the microporous layer (MPL), and the catalyst layer (CL). The standard Leverett J-Function under-predicted drainage curves for the DM at high saturation levels and significantly under-predicted the capillary pressure requirements for the MPL and CL across the entire saturation range. Composite structures were tested to understand interfacial effects for DM vertical bar MPL and MPL vertical bar CL. Each additional layer was found to superimpose its effects on capillary pressure onto the previous layers. The MPL formulation tested increased in porosity from a 136 nm peak average to a 153 nm peak average with increased surface porosity of the substrate. Additionally, small voids and pockets that accumulate liquid water were found to exist in the MPLICL interface. The results of this work are useful for computational modelers seeking to enhance the resolution of their macroscopic multi-phase flow models which underestimate capillary pressure using the standard Leverett J-Function. (C) 2014 Elsevier B.V. All rights reserved.

【 授权许可】

Free