An Analytical Model of the Membrane Electrode Assembly in a PEMFC

2005 ◽  
Author(s):  
S. Litster ◽  
N. Djilali
Keyword(s):  
Fuel Cells ◽  
Analytical Model ◽  
Polymer Electrolyte Membrane ◽  
Finite Thickness ◽  
Catalyst Layer ◽  
Ambient Air ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Electrolyte Membrane ◽  
Catalyst Layers

An analytical model of the membrane electrode assembly (MEA) in a polymer electrolyte membrane fuel cell (PEM) has been developed for investigating the effect of catalyst layer specifications. Emphasis is placed on the cathode catalyst layer, which is modeled using a finite-thickness formulation with parameters obtained from a variable-width macrohomogeneous model. The variable-width formulation accounts for the effect of changing catalyst layer specifications on the dimensions of the catalyst layer by assuming a constant void fraction. Interest in low-humidity operation of micro-fuel cells that are passively fed ambient air has facilitated the present derivations and assumptions. The model is shown to agree well with experimental data over a substantial range of catalyst layer specifications. In addition, the model shows excellent promise as a tool for optimizing catalyst layers in micro-fuel cells with passive ambient air breathing.

Influence of Ammonia on Membrane-Electrode Assemblies in Polymer Electrolyte Fuel Cells

2009 ◽  
Author(s):  
Xiaoyu Zhang ◽  
Joshua Preston ◽  
Ugur Pasaogullari ◽  
Trent Molter
Keyword(s):  
Polymer Electrolyte ◽  
Electrochemical Impedance ◽  
Polymer Electrolyte Membrane ◽  
Catalyst Layer ◽  
Polymer Electrolyte Fuel Cell ◽  
Membrane Electrode ◽  
Electrolyte Membrane ◽  
Catalyst Layers ◽  
Electrode Assemblies ◽  
And Performance

An experimental investigation of contamination of polymer electrolyte fuel cell (PEFC) membranes and catalyst layers with ammonia (NH3) is reported. Cyclic voltammetry (CV) scans and electrochemical impedance spectroscopy (EIS) analyses show that trace amounts of ammonia can significantly contaminate both the polymer electrolyte membrane (PEM) and the catalyst layers. The results show that the catalyst layer contamination can be reversed under certain conditions, while the membrane recovery tends to be much slower, and permanent effects of ammonia contamination is observed. Mechanisms of contamination of the polymer electrolyte and catalyst layers, and performance degradation of the PEFC are also postulated.

scholarly journals Highly Durable Direct Methanol Fuel Cell with Double-Layered Catalyst Cathode

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Liu ◽  
Chun-Tao Liu ◽  
Lei Zhao ◽  
Zhen-Bo Wang
Keyword(s):  
Direct Methanol Fuel Cells ◽  
Polymer Electrolyte Membrane ◽  
Membrane Integrity ◽  
Catalyst Layer ◽  
Membrane Electrode Assembly ◽  
Free Radical Scavengers ◽  
Membrane Electrode ◽  
Electrolyte Membrane ◽  
Direct Methanol ◽  
Layered Catalyst

Polymer electrolyte membrane (PEM) is one of the key components in direct methanol fuel cells. However, the PEM usually gets attacked by reactive oxygen species during the operation period, resulting in the loss of membrane integrity and formation of defects. Herein, a double-layered catalyst cathode electrode consisting of Pt/CeO2-C as inner catalyst and Pt/C as outer catalyst is fabricated to extend the lifetime and minimize the performance loss of DMFC. Although the maximum power density of membrane electrode assembly (MEA) with catalyst cathode is slightly lower than that of the traditional one, its durability is significantly improved. No obvious degradation is evident in the MEA with double-layered catalyst cathode within durability testing. These results indicated that Pt/CeO2-C as inner cathode catalyst layer greatly improved the stability of MEA. The significant reason for the improved stability of MEA is the ability of CeO2to act as free-radical scavengers.

scholarly journals Depositing Catalyst Layers in Polymer Electrolyte Membrane Fuel Cells: A Review

2015 ◽  
Vol 12 (6) ◽  
Author(s):  
Austin Strong ◽  
Courtney Thornberry ◽  
Shane Beattie ◽  
Rongrong Chen ◽  
Stuart R. Coles
Keyword(s):  
Polymer Electrolyte Membrane ◽  
Membrane Electrode Assembly ◽  
Membrane Electrode ◽  
Improve Performance ◽  
Electrolyte Membrane ◽  
The Past ◽  
Catalyst Layers ◽  
Energy Needs ◽  
Promising Solution ◽  
Manufacturing Techniques

Fuel cell technology continues to advance and offers to be a potentially promising solution to many energy needs. Of particular interest are manufacturing techniques to improve performance and decrease overall cost. For catalyst deposition on the membrane electrode assembly (MEA), there are a number of techniques that have been used in the past decades. This paper aims to review many of these main techniques that have been published to show the wide variety of catalyst deposition methods.

scholarly journals Components for PEM Fuel Cells: An Overview

2010 ◽  
Vol 657 ◽  
pp. 143-189 ◽  
Author(s):  
T. Maiyalagan ◽  
Sivakumar Pasupathi
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte Membrane ◽  
Membrane Electrode Assembly ◽  
Energy Conversion Efficiency ◽  
Direct Conversion ◽  
High Energy ◽  
Pem Fuel Cells ◽  
Pollutant Emission ◽  
Membrane Electrode ◽  
Electrolyte Membrane

Fuel cells, as devices for direct conversion of the chemical energy of a fuel into electricity by electrochemical reactions, are among the key enabling technologies for the transition to a hydrogen-based economy. Among the various types of fuel cells, polymer electrolyte membrane fuel cells (PEMFCs) are considered to be at the forefront for commercialization for portable and transportation applications because of their high energy conversion efficiency and low pollutant emission. Cost and durability of PEMFCs are the two major challenges that need to be addressed to facilitate their commercialization. The properties of the membrane electrode assembly (MEA) have a direct impact on both cost and durability of a PEMFC. An overview is presented on the key components of the PEMFC MEA. The success of the MEA and thereby PEMFC technology is believed to depend largely on two key materials: the membrane and the electro-catalyst. These two key materials are directly linked to the major challenges faced in PEMFC, namely, the performance, and cost. Concerted efforts are conducted globally for the past couple of decades to address these challenges. This chapter aims to provide the reader an overview of the major research findings to date on the key components of a PEMFC MEA.

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