Two-Phase Transport in Polymer Electrolyte Fuel Cells with Bilayer Cathode Gas Diffusion Media
- 1 January 2005
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 152 (8), A1574-A1582
- https://doi.org/10.1149/1.1938067
Abstract
A two-phase, full cell model based on the multiphase mixture (M2)(M2) framework is developed to analyze the two-phase transport in polymer electrolyte fuel cells with bilayer cathode gas diffusion media (GDM), consisting of a coarse gas diffusion layer (GDL) with an average pore size around 10-30μm10-30μm and a microporous layer (MPL) with an average pore size ranging from 0.1 to 1μm1μm . Effects of the relevant properties of the MPL on liquid water transport are examined, including average pore size, wettability, thickness, and porosity. It is quantitatively shown that the MPL increases the rate of water back-flow across the membrane toward the anode by increasing the hydraulic pressure differential across the membrane, consequently reducing the net amount of water to be removed from the cathode. Furthermore, it is seen that different microporous and wetting characteristics of the MPL cause a discontinuity in the liquid saturation profile at the MPL-GDL interface, which in turn reduces the amount of liquid water in the catalyst layer-MPL interface. Our analyses show that the back-flow of liquid water increases with increasing hydrophobicity and thickness, and decreasing pore size and porosity of the MPL.Keywords
This publication has 31 references indexed in Scilit:
- Enhancement of PEM fuel cell performance by steaming or boiling the electrodeJournal of Power Sources, 2002
- Influence of pore-size distribution of diffusion layer on mass-transport problems of proton exchange membrane fuel cellsJournal of Power Sources, 2002
- Water transport in the proton-exchange-membrane fuel cell: measurements of the effective drag coefficientJournal of Power Sources, 2001
- Effects of the Diffusion Layer Characteristics on the Performance of Polymer Electrolyte Fuel Cell ElectrodesJournal of Applied Electrochemistry, 2001
- Effect of diffusion-layer morphology on the performance of polymer electrolyte fuel cells operating at atmospheric pressureJournal of Applied Electrochemistry, 2000
- Effects of Nafion impregnation on performances of PEMFC electrodesElectrochimica Acta, 1998
- Influence of the PTFE content in the diffusion layer of low-Pt loading electrodes for polymer electrolyte fuel cellsElectrochimica Acta, 1998
- Influence of the structure in low-Pt loading electrodes for polymer electrolyte fuel cellsElectrochimica Acta, 1998
- An advanced gas diffusion electrode for high performance phosphoric acid fuel cellsJournal of Electroanalytical Chemistry, 1996
- Low platinum loading electrodes for polymer electrolyte fuel cells fabricated using thermoplastic ionomersElectrochimica Acta, 1995