Synchrotron X-Ray Investigation of Membrane Water Distribution in Polymer Electrolyte Membrane Fuel Cell Applications

2017 ◽  
Author(s):  
Rupak Banerjee ◽  
Chuzhang Han ◽  
Nan Ge ◽  
Aimy Bazylak
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Current Density ◽  
Water Distribution ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion ◽  
Cell Performance ◽  
X Ray ◽  
Electrolyte Membrane

Water management is a critical component of extracting optimum performance and efficiency from polymer electrolyte membrane (PEM) fuel cells. During fuel cell operation, a balance needs to be maintained between excess water blocking the reactant pathways through the gas diffusion layer, and the requirement for membrane hydration. The ionic conductivity through the membrane depends strongly on the hydration of the membrane. The reactant gases in a PEM fuel cell are supplied through a humidification system to maintain appropriate levels of hydration in the membrane. The removal of the anode humidifier would significantly reduce the balance of plant costs and reduce the volume required for the fuel cell in an automotive setting. However, removing the anode humidification system could have adverse effects on membrane hydration and on fuel cell performance. In this study, the anode humidification was varied and the cell performance and the membrane resistance were monitored. Synchrotron X-ray radiography was conducted simultaneously to visualize the water distribution in the membrane, the gas diffusion layer, and the associated interfaces. It was observed that the anode humidification had a strong impact on the performance of the fuel cell, with the dry condition leading to voltage instability at a current density below 1.0 A/cm2. The membrane water content was observed to decrease with increases in operating current density.

Effect of Gas Diffusion Layer With Double-Side Microporous Layer Coating on Polymer Electrolyte Membrane Fuel Cell Performance

2013 ◽  
Vol 10 (2) ◽  
Author(s):  
Hao-Ming Chang ◽  
Min-Hsing Chang
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Acetylene Black ◽  
Microporous Layer ◽  
Electrolyte Membrane

In this study, the performance of a polymer electrolyte membrane fuel cell with double-side microporous layer (MPL) coating on gas diffusion layer (GDL) is investigated experimentally. A standard commercial SGL® 10BA carbon paper is used as the substrate and it is coated with MPL on both sides of the paper with different composition. Three different carbon powders are used in the experiments, including Vulcan XC-72R, Acetylene black, and Black Pearls 2000. The effect of polytetrafluoroethylene (PTFE) content is also considered. A single cell testing apparatus is constructed to measure the cell performance and evaluate the effect of GDL with double-side MPL coating. Accordingly, the optimal fabrication parameters of double-side MPL are determined. The result shows that under the same operating conditions, the performance of fuel cell using GDL with double-side MPL is better than that using general single-side MPL. The Acetylene black is found to give the best cell performance than the others. The optimal composition of MPL on the surfaces facing to the catalyst layer and flow-channel plate are 1.25 mg/cm2 and 0.25 mg/cm2, respectively. Besides, the optimal PTFE content is the same on both sides of MPL which is found to be 20 wt%.

Modeling the Effective Thermal Conductivity of an Anisotropic Gas Diffusion Layer in a Polymer Electrolyte Membrane Fuel Cell

2011 ◽  
Author(s):  
J. Yablecki ◽  
A. Bazylak
Keyword(s):  
Thermal Conductivity ◽  
Fuel Cell ◽  
Effective Thermal Conductivity ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Compaction Pressure ◽  
Polymer Electrolyte Membrane ◽  
Gas Diffusion Layer ◽  
Gas Diffusion ◽  
Electrolyte Membrane

The anisotropic and heterogeneous effective thermal conductivity of the gas diffusion layer (GDL) of the polymer electrolyte membrane fuel cell was determined in the through-plane direction using an analytical thermal resistance model. The geometry of the GDL was reconstructed using porosity profiles obtained through microscale computed tomography imaging of four commercially available GDL materials. The effective thermal conductivity increases almost linearly with increasing bipolar plate compaction pressure. The effective thermal conductivity was also seen to increase with increasing GDL thickness as bulk porosity remained almost constant. The effect of the heterogeneous through-plane porosity distribution on the effective thermal conductivity is discussed. The outcomes of this work will provide insight into the effect of heterogeneity and anisotropy of the GDL on the thermal management required for improved PEMFC performance.

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