Novel Testing Method for Fuel Cell Hardware Design and Assembly

2005 ◽  
Vol 2 (3) ◽  
pp. 197-201 ◽  
Author(s):  
Fang-Bor Weng ◽  
Ay Su ◽  
Yur-Tsai Lin ◽  
Guo-Bin Jung ◽  
Yen-Ming Chen
Keyword(s):  
Fuel Cell ◽  
Gas Permeability ◽  
Low Cost ◽  
Aluminum Foil ◽  
Cell Performance ◽  
Carbon Paper ◽  
Membrane Electrode ◽  
Testing Method ◽  
Ohmic Resistance ◽  
Hardware Development

A simple, low-cost testing method is proposed for fuel cell hardware development. A perforated aluminum foil with an array of small holes covered with carbon paper or cloth replaces the membrane electrode assemblies to test the contact resistance and gas permeability of the carbon paper. Practical fuel cells of 50cm2 reaction area with different gasket thicknesses and compressed pressures are tested for performance. The results of ohmic resistance and permeability of compressed carbon paper indicate strong relevance to cell performance, demonstrating that this novel testing method is valuable for fuel cell hardware development. Also, the compression mechanism of the diffusion layer is discussed along with a proposal for a strategy for improving cell performance. After that, an advanced design of a 25cm2 single cell is developed. The results of cell performance of the advanced cell are acceptable and competitive with the performance data of commercial products.

Effects of Assembly Pressure on the Gas Diffusion Layer and Performance of a PEM Fuel Cell

2011 ◽  
Vol 110-116 ◽  
pp. 48-52 ◽  
Author(s):  
Hao Ming Chang ◽  
Min Hsing Chang
Keyword(s):  
Fuel Cell ◽  
Diffusion Layer ◽  
Gas Permeability ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Carbon Paper ◽  
Membrane Electrode ◽  
Clamping Pressure

Assembly pressure plays an important role in the factors affecting the performance of a PEM fuel cell. An insufficient clamping pressure may cause large contact resistance and thus lower the cell performance. On the other hand, over-clamping may reduce the porosity and permeability of the gas diffusion layer (GDL) and also result in poor cell performance. Therefore, it is very important to determine the proper assembly pressure for obtaining optimal performance. In this study, we design a special test fixture to evaluate the effect of assembly pressure on the performance of a PEM fuel cell. Without disassembling the fuel cell, the clamping pressure can be adjusted in situ to measure the cell performance directly and precisely. The unique single cell design eliminates the influence of gasket around the membrane electrode assembly (MEA) and makes it possible to estimate the compression effect of GDL independently. Three different types of carbon paper are used in the experiments as the GDLs. The variations of water contact angle, gas permeability, and in-plane electrical resistivity with the assembly pressure are also measured to explore the effects of assembly pressure on these physical properties. The results show that an optimal assembly pressure is always observed in each case, indicating an adequate compression on GDL is quite necessary for fuel cells.

Probing the influence of the gas diffusion layer on water retention in membrane electrode assemblies via electrochemical impedance spectroscopy

2018 ◽  
Author(s):  
Foroughazam Afsahi ◽  
E. Bradley Easton
Keyword(s):  
Fuel Cell ◽  
Electrochemical Impedance ◽  
Catalyst Layer ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Carbon Paper ◽  
Membrane Electrode ◽  
Fuel Cell Performance ◽  
Electrode Assemblies

The effect of the relative humidity (RH) of supplied gases on PEM fuel cell performance was monitored by electrochemical impedance spectroscopy (EIS). Two different Nafion®-based membrane electrode assemblies (MEAs) were prepared from two commercially available gas diffusion layers (GDLs) based on carbon paper and carbon cloth. By performing EIS measurements under condition where the transmission line model was applicable, both the ionic resistance in catalyst layer (RΣ) and the membrane resistance (Rmem) could be probed. The extent of this impact, however, depends on the GDL substrate properties and the electrode side to which the dry gas was fed. Overall, the carbon paper based MEA provided better fuel cell performance when the dry gas condition was applied, whereas the cloth based MEA revealed better fuel cell performance with fully saturated reactant gases. Moreover, the later one demonstrates a better capability to address the flooding issue at high current density even when symmetric dry gas arrangement (both dry fuel and oxidant gases) was studied. Variation of fuel gas RH at the anode perturb the fuel cell performance less strongly compared with the other arrangements. This implies that with the fully hydrated cathode gas water transport via back diffusion from the cathode to the anode could maintain the hydrated membrane and catalyst layer to some extent. By using this EIS methodology, the interplay of GDL properties and reactant gases RH on PEM fuel cell performance can be more clearly understood.

Nafion/PBI Nanofiber Composite Membranes for Fuel Cells Applications

2010 ◽  
Author(s):  
Tzyy-Lung Leon Yu ◽  
Shih-Hao Liu ◽  
Hsiu-Li Lin ◽  
Po-Hao Su
Keyword(s):  
Thin Film ◽  
Fuel Cell ◽  
Composite Membrane ◽  
Fiber Composite ◽  
Composite Membranes ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Membrane Thickness ◽  
Fuel Cell Performance ◽  
Nano Fiber

The PBI (poly(benzimidazole)) nano-fiber thin film with thickness of 18–30 μm is prepared by electro-spinning from a 20 wt% PBI/DMAc (N, N′-dimethyl acetamide) solution. The PBI nano-fiber thin film is then treated with a glutaraldehyde liquid for 24h at room temperature to proceed chemical crosslink reaction. The crosslink PBI nano-fiber thin film is then immersed in Nafion solutions to prepare Nafion/PBI nano-fiber composite membranes (thickness 22–34 μm). The morphology of the composite membranes is observed using a scanning electron microscope (SEM). The mechanical properties, conductivity, and unit fuel cell performance of membrane electrode assembly (MEA) of the composite membrane are investigated and compared with those of Nafion-212 membrane (thickness ∼50 μm) and Nafion/porous PTFE (poly(tetrafluoro ethylene)) composite membrane (thickness ∼22 μm). We show the present composite membrane has a similar fuel cell performance to Nafion/PTFE and a better fuel cell performance than Du Pont Nafion-212.

Platinum-Catalyzed Polymer Electrolyte Membrane for Fuel Cells

1999 ◽  
Vol 575 ◽  
Author(s):  
T. Jan Hwang ◽  
Hong Shao ◽  
Neville Richards ◽  
Jerome Schmitt ◽  
Andrew Hunt ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Low Cost ◽  
Polymer Electrolyte Membrane ◽  
Chemical Vapor ◽  
Proton Exchange ◽  
Fabrication Process ◽  
Membrane Electrode ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane

ABSTRACTThe objective of this research is to develop the combustion chemical vapor deposition (CCVD) process for low-cost manufacture of catalytic coatings for proton exchange membrane fuel cell (PEMFC) applications. The platinum coatings as well as the fabrication process for membrane-electrode-assemblies (MEAs) were evaluated in a single testing fuel cell using hydrogen/oxygen. It was found that increasing the platinum loading from 0.05 to 0.1 mg/cm2 did not increase the fuel cell performance. The in-house MEA fabrication process needs to be improved to reduce the cell resistance. Significantly higher performance of Pt coating by the CCVD process has been obtained by MCT's fuelcell industry collaborators who are more experienced with MEA fabrication. The results can not be revealed due to confidentiality agreements.

scholarly journals Optimization of Membrane Electrode Assembly of PEM Fuel Cell by Response Surface Method

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3097 ◽  
Author(s):  
Vuppala ◽  
Chedir ◽  
Jiang ◽  
Chen ◽  
Aziz ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Response Surface ◽  
Response Surface Method ◽  
Current Density ◽  
Membrane Electrode Assembly ◽  
Proton Exchange ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Membrane Thickness ◽  
Surface Method

The membrane electrode assembly (MEA) plays an important role in the proton exchange membrane fuel cell (PEMFC) performance. Typically, the structure comprises of a polymer electrolyte membrane sandwiched by agglomerate catalyst layers at the anode and cathode. Optimization of various parameters in the design of MEA is, thus, essential for reducing cost and material usage, while improving cell performance. In this paper, optimization of MEA is performed using a validated two-phase PEMFC numerical model. Key MEA parameters affecting the performance of a single PEMFC are determined from sensitivity analysis and are optimized using the response surface method (RSM). The optimization is carried out at two different operating voltages. The results show that membrane thickness and membrane protonic conductivity coefficient are the most significant parameters influencing cell performance. Notably, at higher voltage (0.8 V per cell), the current density can be improved by up to 40% while, at a lower voltage (0.6 V per cell), the current density may be doubled. The results presented can be of importance for fuel cell engineers to improve the stack performance and expedite the commercialization.

In-Plane Microstructure of Gas Diffusion Layers With Different Properties for PEFC

2013 ◽  
Author(s):  
Mehdi Mortazavi ◽  
Kazuya Tajiri
Keyword(s):  
Contact Angle ◽  
Fuel Cell ◽  
Pore Diameter ◽  
Gas Transport ◽  
Gas Permeability ◽  
Transport Phenomena ◽  
Gas Diffusion ◽  
Polymer Electrolyte Fuel Cell ◽  
Diameter Distribution ◽  
Carbon Paper

Gas diffusion layer (GDL) is undoubtedly one of the most complicated components used in a polymer electrolyte fuel cell (PEFC) in terms of liquid and gas transport phenomena. An appropriate fuel cell design seeks a fundamental study of this tortuous porous component. Currently, porosity and gas permeability have been known as some of the key parameters affecting liquid and gas transport through GDL. Although these are dominant parameters defining mass transport through porous layers, there are still many other factors affecting transport phenomena as well as overall cell performance. In this work, microstructural properties of Toray carbon papers with different thicknesses and for polytetrafluoroethylene (PTFE) treated and untreated cases have been studied based on scanning electron microscopy (SEM) image analysis. Water droplet contact angle as a dominant macroscale property as well as mean pore diameter, pore diameter distribution, and pore roundness distribution as important microscale properties have been studied. It was observed that the mean pore diameter of Toray carbon paper does not change with its thickness and PTFE content. Mean pore diameter for Toray carbon papers was calculated to be around 26μm regardless of their thicknesses and PTFE content. It was also observed that droplet contact angle on GDL surface does not vary with GDL thickness. The average contact angle for 10 wt.% PTFE treated GDLs of different thicknesses was measured about 150°. Finally, the heterogeneous in-plane PTFE distribution on the GDL surface was observed to have no effect on mean pore diameter of GDLs.

The effect of water uptake gradient in membrane electrode assembly on fuel cell performance

2011 ◽  
Vol 80 (2) ◽  
pp. 201-206 ◽  
Author(s):  
H. Fujita ◽  
F. Shiraki ◽  
Y. Oshima ◽  
T. Tatsumi ◽  
T. Yoshikawa ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Water Uptake ◽  
Membrane Electrode Assembly ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Fuel Cell Performance ◽  
Effect Of Water

Effect of Membrane Electrode Assembly Bonding Technique on Fuel Cell Performance and Platinum Crystallite Size

2014 ◽  
Vol 11 (3) ◽  
Author(s):  
Steven Buelte ◽  
Daniel Walczyk ◽  
Ian Sweeney
Keyword(s):  
Fuel Cell ◽  
Phosphoric Acid ◽  
Crystallite Size ◽  
Cycle Time ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Manufacturing Costs ◽  
Cell Technology ◽  
New Methods ◽  
Ultrasonic Bonding

Major efforts are underway to reduce fuel cell manufacturing costs, thereby facilitating widespread adoption of fuel cell technology in emerging applications, such as combined heat and power and transportation. This research investigates new methods for fabricating membrane electrode assemblies (MEAs), which are at the core of fuel cell technology. A key manufacturing step in the production of fuel cell MEAs is bonding two electrodes to an ionically conductive membrane. In particular, new MEA bonding methods are examined for polybenzimidazole-based phosphoric acid (PBI/PA) fuel cells. Two new methods of bonding PBI/PA fuel cell MEAs were studied with the goal of reducing cycle time to reduce manufacturing costs. Specifically, the methods included ultrasonic bonding and thermally bonding with advance process control (APC thermal). The traditional method of thermally bonding PBI MEAs requires 30 seconds, whereas the new bonding methods reduce the cycle time to 2 and 8 seconds, respectively. Ultrasonic bonding was also shown to significantly reduce the energy consumed by the bonding process. Adverse effects of the new bonding methods on cell performance and structure were not observed. Average cell voltages at 0.2 A/cm2 for ultrasonic, APC thermal, and thermally bonded MEAs were 650 mV, 651 mV, and 641 mV, respectively. The platinum crystallite size was found to be the same before and after ultrasonic bonding using XRD. Furthermore, changes in the electrode pore structure were not observed in SEM images taken after ultrasonic bonding. The test results show that it is possible to reduce manufacturing costs by switching to faster methods of bonding PBI phosphoric acid fuel cell MEAs.

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