Water Flow in and around the MEA of PEM Fuel Cell
Abstract
In order to avoid the “water flooding”, the excess water generating in PEM fuel cell should be drained timely. In this study, an experiment model was applied to analyze the path of water flow corresponding to the flow resistances based on the “flooding” between catalyst layer (CL) and gas diffusion layer (GDL). Narrow apertures in the largest pores of carbon paper gas diffusion layer are the primary resistance to liquid water penetration. After sufficient hydrostatic pressure is applied, water penetrates the limiting aperture and flows through the pore reaching the GDL surface. For the carbon paper GDL material, the pressure(~1 kPa)required for water to flow through the pores is much less than the pressure (~6 kPa) to penetrate the limiting aperture of the pores. Adding micro-porous layer (MPL) can obviously increase water penetrate resistance. The content of Teflon in the MPL has little effect on the water penetration pressure. It is helpful to promote the water management in fuel cell by setting pilot holes on the carbon paper GDL material.
Keywords: fuel cell, water flow, gas diffusion layer, limiting aperture, penetration pressure
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BENZIGER J. NEHLSEN J. BLACKWELL d, et al. Water flow in the gas diffusion layer of PEM fuel cells [J]. Journal of Membrane Science. 2005. 261(1): 98— 106.
KIMBALL E, WHITAKER T, KEVREK1D1S Y G, et al. Drops, slugs, and flooding in polymer electrolyte membrane fuel cells [J]. AIChE Journal, 2008. 54(5): 1313- 1332.
ELLER J. ROSEN T, MARONE F. et al. Progress in in situ X-ray tomographic microscopy of liquid water in gas diffusion layers of PEFC [J]. Journal of the Electrochemical Society, 2011, 158(8): B963-B970.
LITSTER S. S1NTON D, DJILALI N. Ex situ visualization of liquid water transport in PEM fuel cell gas diffusion layers [J]. Journal of Power Sources. 2006, 154(1): 95—105.
LU Z. DAINO M M. RATH C. et al. Water management studies in PEM fuel cells, part 111: dynamic breakthrough and intermittent drainage characteristics from GDLs with and without MPLs [J]. International Journal of Hydrogen Energy, 2010, 35(9): 4222-4233.
PARK S, POPOV В N. Effect of cathode GDL characteristics on mass transport in PEM fuel cells [J]. Fuel. 2009, 88(11): 2068-2073.
PARK S, POPOV В N. Effect of a GDL based on carbon paper or carbon cloth on PEM fuel cell performance [J]. Fuel, 2011 , 90(1): 436-440.
BEVERS D. ROGERS R. VON BRADК M. Examination of the influence of Teflon coating on the properties of carbon paper in polymer electrolyte fuel cells [J]. Journal of Power Sources, 1996, 63(2): 193-201.
LIN G. VAN NGUYEN T. A two-dimensional two-phase model of a PE.VI fuel cell [J]. Journal of the Electrochemical Society, 2006. 153(2): А372-Д382.
PARK G G. SOI IN Y J. YANG TH. et al. Effect of Teflon contents in the gas diffusion media on the performance of PEMFC [J]. Journal of Power Sources. 2004. 131(1): 182 — 187.
FISHMAN Z. BAZYLAK A. Heterogeneous through-plane porosity distributions for treated PEMFC GDLs I. Teflon effect [J]. Journal of the Electrochemical Society. 2011. 158 (8): B841-B845.
LOBATO J. CA IZARES P. RODRIGO M. et al. Influence of the Teflon loading in the gas diffusion layer of PBI-based PEM fuel cells [J]. Journal of Applied Electrochemistry. 2008. 38(6): 793-802.
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