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.

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.

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.

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

Enhancement of PEM Fuel Cell Performance by Flow Control

2014 ◽  
Vol 804 ◽  
pp. 75-78 ◽  
Author(s):  
Vinh Nguyen Duy ◽  
Jung Koo Lee ◽  
Ki Won Park ◽  
Hyung Man Kim
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Pem Fuel Cell ◽  
Membrane Electrode Assembly ◽  
Cell Performance ◽  
Field Pattern ◽  
Battery Life ◽  
Membrane Electrode ◽  
Fuel Cell Performance ◽  
Serpentine Flow Field

Flow-field design affects directly to the PEM fuel cell performance. This study aims to stimulate the under-rib convection by adding sub-channels and by-passes to the conventional-advanced serpentine flow-field to improve the PEM fuel cell performance. The experimental results show that if reacting gases flow in the same direction as the neighboring main channels, the under-rib convection shows a flow from the main channels to the sub-channels makes progress in reducing pressure drop and enhancing uniform gas supply and water diffusion. Alternatively, if in the direction opposite to that of the neighboring main channels, the under-rib convection shows a flow from the inlet side towards the outlet side across the sub-channel as in the conventional serpentine channels. Analyses of the local transport phenomena in the cell suggest that the inlet by-pass supplies the reacting gases uniformly from the entrance into the sub-channels and the outlet by-pass enhances water removal. Novel serpentine flow-field pattern employing sub-channels and by-passes shows uniform current density and temperature distribution by uniformly supplying the reacting gas. Furthermore, performance improvement of around 20% is observed from the experimental performance evaluation. As a result, longer battery life is expected by reducing the mechanical stress of membrane electrode assembly.

scholarly journals Novel phosphoric acid-doped PBI-blends as membranes for high-temperature PEM fuel cells

2015 ◽  
Vol 3 (20) ◽  
pp. 10864-10874 ◽  
Author(s):  
Florian Mack ◽  
Karin Aniol ◽  
Corina Ellwein ◽  
Jochen Kerres ◽  
Roswitha Zeis
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Phosphoric Acid ◽  
Chemical Stability ◽  
Pem Fuel Cells ◽  
Cell Performance ◽  
Acid Base ◽  
Fuel Cell Performance ◽  
Blend Membranes

We present novel acid–base blend membranes with improved chemical stability and competitive fuel cell performance compared to conventional PBI membranes.

scholarly journals Influence of Ionomer Content in the Catalytic Layer of MEAs Based on Aquivion® Ionomer

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3832
Author(s):  
Irene Gatto ◽  
Ada Saccà ◽  
David Sebastián ◽  
Vincenzo Baglio ◽  
Antonino Salvatore Aricò ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Cell Performance ◽  
Membrane Electrode ◽  
Catalytic Layer ◽  
Fuel Cell Performance ◽  
Dispersing Agent ◽  
Electrode Assemblies ◽  
Electrolyte Membranes ◽  
Perfluorinated Sulfonic Acid ◽  
Catalyst Utilization

Perfluorinated sulfonic acid (PFSA) polymers such as Nafion® are widely used for both electrolyte membranes and ionomers in the catalytic layer of membrane-electrode assemblies (MEAs) because of their high protonic conductivity, σH, as well as chemical and thermal stability. The use of PFSA polymers with shorter side chains and lower equivalent weight (EW) than Nafion®, such as Aquivion® PFSA ionomers, is a valid approach to improve fuel cell performance and stability under drastic operative conditions such as those related to automotive applications. In this context, it is necessary to optimize the composition of the catalytic ink, according to the different ionomer characteristics. In this work, the influence of the ionomer amount in the catalytic layer was studied, considering the dispersing agent used to prepare the electrode (water or ethanol). Electrochemical studies were carried out in a single cell in the presence of H2-air, at intermediate temperatures (80–95 °C), low pressure, and reduced humidity (50% RH. %). The best fuel cell performance was found for 26 wt.% Aquivion® at the electrodes using ethanol for the ink preparation, associated to a maximum catalyst utilization.

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