Effect of PTFE on Thermal Conductivity of Gas Diffusion Layers of PEM Fuel Cells

2013 ◽  
Author(s):  
Hamidreza Sadeghifar ◽  
Ned Djilali ◽  
Majid Bahrami
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Contact Resistance ◽  
Performance Modeling ◽  
Mechanistic Model ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
First Time

Through-plane thermal conductivity of 14 SIGRACET gas diffusion layers (GDLs), including series 24 & 34, as well as 25 & 35, are measured under different compressive pressures, ranging from 2 to 14 bar, at the temperature of around 60 °C. The effect of compression, PTFE loadings, and micro porous layer (MPL) on thermal conductivity of the GDLs and their contact resistance with an iron clamping surface is experimentally investigated. The contact resistance of MPL coated on GDL with the substrate of that GDL is measured for the first time in this paper. A new robust mechanistic model is presented for predicting the through-plane thermal conductivity of GDLs treated with PTFE and is successfully verified with the present experimental data. The model can predict the experimentally-observed reduction in thermal conductivity as a result of PTFE treatment and provides detailed insights on performance modeling of PEMFCs.

scholarly journals Through-Plane Gas Permeability of Proton Exchange Membrane Fuel Cell Gas Diffusion Layers

2011 ◽  
Author(s):  
A. Tamayol ◽  
F. McGregor ◽  
M. Bahrami
Keyword(s):  
Experimental Data ◽  
Gas Permeability ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Mechanical Compression ◽  
Test Bed ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
Wide Range

Effects of mechanical compression and PTFE content on the through-plane gas permeability of gas diffusion layers (GDLs) of PEM fuel cells are investigated both experimentally and theoretically. A new test bed is designed and built which allows pressure drop and air flow rate measurement for various fibrous samples. The measured values are used to calculate the through-plane permeability. Various GDLs are obtained and tested over a wide range of PTFE content and compression ratio. The experimental data shows a reverse relationship between the through-plane permeability and both PTFE content and mechanical compression. An existing model for through-plane permeability of planar structures is revisited to develop a model that accommodates effects of PTFE content and GDL compression. The proposed model captures the trends of the experimental data for through-plane permeability, measured in the present study or reported by others.

Electrical Contact Resistance Between Gas Diffusion Layers and Bipolar Plates for Applications to PEM Fuel Cells

2004 ◽  
Author(s):  
V. Mishra ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Contact Resistance ◽  
Electrical Contact ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Surface Geometry ◽  
Electrical Contact Resistance ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
Wide Range

The electrical contact resistance between gas diffusion layers and bi-polar flow channel plates is one of the important factors contributing to the operational voltage loss in fuel cells. Effective analysis and design of fuel cells therefore need to account for the contact resistance in deriving the polarization curve for the cell. Despite its significance, relatively scant work is reported in the open literature on the measurement and modeling of the contact resistance in fuel cell systems, and the present work aims to fill this void. Experimental data are reported for the first time to show the effects of different gas diffusion layer materials and contact pressure on the electrical contact resistance. A fractal asperity based model is adopted to predict the contact resistance as a function of pressure, material properties, and surface geometry. Good agreement is observed between the data and the model predictions for a wide range of contacting pressures and materials.

Measurement and Prediction of Electrical Contact Resistance Between Gas Diffusion Layers and Bipolar Plate for Applications to PEM Fuel Cells

2004 ◽  
Vol 1 (1) ◽  
pp. 2-9 ◽  
Author(s):  
V. Mishra ◽  
F. Yang ◽  
R. Pitchumani
Keyword(s):  
Fuel Cells ◽  
Contact Resistance ◽  
Electrical Contact ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Surface Geometry ◽  
Electrical Contact Resistance ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
Wide Range

The electrical contact resistance between gas diffusion layers and bipolar flow channel plates is one of the important factors contributing to the operational voltage loss in polymer electrolyte membrane (PEM) fuel cells. Effective analysis and design of fuel cells therefore need to account for the contact resistance in deriving the polarization curve for the cell. Despite its significance, relatively scant work is reported in the open literature on the measurement and modeling of the contact resistance in fuel cell systems, and the present work aims to fill this void. Experimental data are reported for the first time to show the effects of different gas diffusion layer materials and contact pressure on the electrical contact resistance. A fractal asperity based model is adopted to predict the contact resistance as a function of pressure, material properties, and surface geometry. Good agreement is observed between the data and the model predictions for a wide range of contacting pressures and materials.

Prediction the Differences of Permeability Between Carbon Fiber Paper and Carbon Fiber Cloth in PEM Fuel Cells

2011 ◽  
Author(s):  
Yuan Gao
Keyword(s):  
Fuel Cells ◽  
Carbon Fiber ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Anisotropic Permeability ◽  
Gas Diffusion Layers ◽  
X Ray ◽  
Diffusion Layers ◽  
Carbon Fiber Cloth ◽  
Carbon Fiber Paper

This study is using the multiple relaxation time Lattice Boltzmann method to calculate the permeability of carbon fiber paper and carbon fiber cloth gas diffusion layers (GDL). The 3D gas diffusion layers are generated by X-ray computed tomography, This method involve generation of 3D digital model of gas diffusion layers acquired through X-ray micro-tomography at resolution of a few micros. The reconstructed 3D images were then read into the LBM model to calculate the anisotropic permeability of carbon fiber paper and carbon fiber cloth GDL. We investigated the relationships between the anisotropic permeability and porosity and compare the difference between the two different kinds of GDLs when they have the similar porosity. We also calculate the permeability with different viscosity and compare the two results from the carbon fiber paper and carbon fiber cloth. It is useful for selection of materials for high performance gas diffusion media and can improve the performance of the fuel cells.

Advanced Gas Diffusion Layers for PEM Fuel Cells

2019 ◽  
Vol 33 (1) ◽  
pp. 1123-1132
Author(s):  
Vesna Stanic ◽  
Jason Tatalovich
Keyword(s):  
Fuel Cells ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
Diffusion Layers
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