Seals and Sealants in PEM Fuel Cell Environments: Material, Design, and Durability Challenges

2004 ◽  
Author(s):  
David A. Dillard ◽  
Shu Guo ◽  
Michael W. Ellis ◽  
John J. Lesko ◽  
John G. Dillard ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Material Design ◽  
Pem Fuel Cells ◽  
Cell System ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Cell Components ◽  
And Performance ◽  
The Cost

Fuel cells have significant potential to improve energy utilization efficiency, but remain quite expensive due to the cost of key components, including the membrane of PEM fuel cells, the catalyst, and the bipolar plates. Due to the cost and significance of these items, extensive research has been devoted to reducing cost and improving the quality and performance of these components. By contrast, seals, sealants, and adhesives play a more mundane role in the overall performance of fuel cells, and yet the failure of these materials can lead to reduced system efficiency, system failure, or even safety concerns. Less attention has been given to the performance and durability of these products, yet as improvements in other fuel cell components are made, these seals are becoming a more critical link in the long term performance of fuel cells. This review paper highlights the importance and background of fuel cell seals; discusses the chemical, thermal, and mechanical environments to which fuel cell seals are subjected; and suggests design and testing protocol improvements that may lead to improved fuel cell system performance.

MODELING OF PEM FUEL CELLS WITH FINITE-THICKNESS CATALYSTS

2009 ◽  
Vol 23 (03) ◽  
pp. 537-540 ◽  
Author(s):  
JIANG HUI YIN ◽  
JUN CAO
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Performance Optimization ◽  
Proton Exchange Membrane ◽  
Cell Model ◽  
Finite Thickness ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
And Performance ◽  
Exchange Membrane

A general proton exchange membrane fuel cell model including two finite-thickness catalysts is developed in this study, allowing for an in-depth understanding of the effects of the two key electrochemical reactions taking place in the two catalysts. The model is used to predict the performances of fuel cells employing two different flow channel designs, providing insights for fuel cell design and performance optimization.

scholarly journals Effective Technique for Improving Electrical Performance and Reliability of Fuel Cells

2017 ◽  
Vol 8 (4) ◽  
pp. 1868
Author(s):  
A. Albarbar ◽  
M. Alrweq
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Content ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Electrical Performance ◽  
And Performance

To optimise the electrical performance of proton exchange membrane (PEM) fuel cells, a number of factors have to be precisely monitored and controlled. Water content is one of those factors that has great impact on reliability, durability and performance of PEM fuel cells. The difficulty in controlling water content lies in the inability to determine correct level of water accumulated inside the fuel cell. In this paper, a model-based technique, implemented in COMSOL, is presented for monitoring water content in PEM fuel cells. The model predicts, in real time, water content taking account of other processes occurring in gas channels, across gas diffusion layers (GDL), electrodes, and catalyst layer (CL) and within the membrane to minimize voltage losses and performance degradation. The level of water generated is calculated as function of cell’s voltage and current. Model’s performance and accuracy are verified using a transparent 500 mW PEM fuel cell. Results show model predicted current and voltage curves are in good agreement with the experimental measurements. The unique feature of this model is that, no special requirements are needed as only current, and voltage of the PEM fuel cell were measured thus, is expected to pave the path for developing non-intrusive control and monitoring systems for fuel cells.

SOFCRoll Development at St. Andrews Fuel Cells Ltd.

2006 ◽  
Vol 4 (2) ◽  
pp. 138-142 ◽  
Author(s):  
Fran G. E. Jones ◽  
Paul A. Connor ◽  
Alan J. Feighery ◽  
Julie Nairn ◽  
Jim Rennie ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Single Unit ◽  
Tape Casting ◽  
Performance Testing ◽  
Production Costs ◽  
Cell Components ◽  
And Performance ◽  
The University ◽  
Power Densities

St. Andrews Fuel Cells Ltd. is a spin-off company (formed in February 2005) from the University of St. Andrews. The company’s focus is on the development of the SOFCRoll fuel cell. The SOFCRoll design is produced from tape casting and is fired in a single unit, offering reduced fuel cell production costs. Additionally, the self-supporting nature of the SOFCRoll geometry removes the need for thick cell components, further reducing cell cost and offering increased power densities. This paper reviews the development of the SOFCRoll concerning the processing and performance testing.

Component Failure Analysis From a Fleet of PEM Fuel Cells

2010 ◽  
Author(s):  
Scott Lux ◽  
Arif Nelson ◽  
Nicholas Josefik ◽  
Franklin Holcomb
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Failure Modes ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Engineering Research ◽  
Cell Components ◽  
The U.S

The U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) managed the Residential Proton Exchange Membrane (PEM) Fuel Cell Demonstration. The U.S. Congress funded this project for fiscal years 2001–2004. A fleet of 91 residential-scale PEM fuel cells, ranging in size from 1–5 kW, was demonstrated at various U.S. Department of Defense (DoD) facilities worldwide. This detailed analysis looks into the most prevalent means of failure in the PEM fuel cell systems as categorized from the stack, reformer, and power-conditioning systems as well as the subsequent subsystems. Also evaluated are the lifespan and failure modes of selected fuel cell components, based on component type, age, and usage. The analysis shows while the fuel cell stack components had the single highest number of outages, the balance of plant made for 60.6% of the total outages. The hydrogen cartridges were the most prevalent component replaced during the entire program. The natural gas fuel cell stacks had the highest average operational lifetime; one stack reached a total of 10,250 hours.

Electrical and Thermal Time Constants Fuel Cell System Identification: A Linear Versus Neural Network Approach

2008 ◽  
Author(s):  
M. T. Outeiro ◽  
Alberto J. L. Cardoso ◽  
R. Chibante ◽  
A. S. Carvalho
Keyword(s):  
Neural Network ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Cell System ◽  
Thermal Time ◽  
Fuel Cell System ◽  
Time Constants ◽  
Made In

The energy generated by PEM fuel cells can be used in many different applications with emphasis to commercial power generation and automotive application. It requires the integration of various subsystems such as chemical, mechanical, fluid, thermal and electrical ones. Their electrical and thermal time constants are important variables to analyze and consider in the development of control strategies of electronic converters. For this purpose, a mathematical model of the PEM fuel cell system was developed in Matlab/Simulink based on a set of equations describing cell operation. The model considers static and dynamic operating conditions of the PEM. Using experimental measurements at different load conditions made in a Nexa™ PEM fuel cell system, analysis based on linear ARX (Autoregressive with Exogenous Input) and neural network methods were made in Matlab in order to identify the electrical and thermal time constant values. Both linear ARX and neural network approaches can successfully predict the values of the time constants variables. However, the identification by the linear ARX is appropriated around the most significant operation points of the PEM system while neural network allows at obtaining a nonlinear global model. The paper intends to be a contribution for the identification of the electrical and thermal time constants of PEM fuel cells through these two methodologies. The linear approach is simple but presents some limitations while the non-linear one is widespread but more complex to be implemented.

Current progress and performance improvement of Pt/C catalysts for fuel cells

2020 ◽  
Vol 8 (46) ◽  
pp. 24284-24306
Author(s):  
Xuefeng Ren ◽  
Yiran Wang ◽  
Anmin Liu ◽  
Zhihong Zhang ◽  
Qianyuan Lv ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Energy Conversion ◽  
Performance Improvement ◽  
Electric Energy ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Carnot Cycle ◽  
High Energy Conversion Efficiency ◽  
And Performance

Fuel cell is an electrochemical device, which can directly convert the chemical energy of fuel into electric energy, without heat process, not limited by Carnot cycle, high energy conversion efficiency, no noise and pollution.

PVD Coated Bipolar Plates for PEM Fuel Cells

2005 ◽  
Vol 2 (4) ◽  
pp. 290-294 ◽  
Author(s):  
Shuo-Jen Lee ◽  
Ching-Han Huang ◽  
Yu-Pang Chen ◽  
Chen-Te Hsu
Keyword(s):  
Corrosion Resistance ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Physical Vapor Deposition ◽  
Corrosion Current ◽  
Pem Fuel Cells ◽  
Bipolar Plates ◽  
Coating Materials ◽  
Pvd Coating ◽  
Simulated Fuel

Aluminum was considered a good candidate material for bipolar plates of the polymer electrolyte membrane (PEM) fuel cells due to its low cost, light weight, high strength and good manufacturability. But there were problems of both chemical and electrochemical corrosions in the PEM fuel cell operating environment. The major goals of this research are to find proper physical vapor deposition (PVD) coating materials which would enhance surface properties by making significant improvements on corrosion resistance and electrical conductivity at a reasonable cost. Several coating materials had been studied to analyze their corrosion resistance improvement. The corrosion rates of all materials were tested in a simulated fuel cell environment. The linear polarization curve of electrochemical method measured by potentiostat instrument was employed to determine the corrosion current. Results of the corrosion tests indicated that all of the coating materials had good corrosion resistance and were stable in the simulated fuel cell environment. The conductivities of the coated layers were better and the resistances changed very little after the corrosion test. At last, single fuel cells were made by each PVD coating material. Fuel cell tests were conducted to determine their performance w.r.t. that was made of graphite. The results of fuel cell tests indicated that metallic bipolar plates with PVD coating could be used in PEM fuel cells.

Analytical and numerical study on cooling flow field designs performance of PEM fuel cell with variable heat flux

2016 ◽  
Vol 30 (16) ◽  
pp. 1650155 ◽  
Author(s):  
Ebrahim Afshari ◽  
Masoud Ziaei-Rad ◽  
Nabi Jahantigh
Keyword(s):  
Heat Flux ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Pressure Drop ◽  
Flow Field ◽  
Pem Fuel Cells ◽  
Coolant Flow ◽  
Temperature Uniformity ◽  
Variable Heat ◽  
Variable Heat Flux

In PEM fuel cells, during electrochemical generation of electricity more than half of the chemical energy of hydrogen is converted to heat. This heat of reactions, if not exhausted properly, would impair the performance and durability of the cell. In general, large scale PEM fuel cells are cooled by liquid water that circulates through coolant flow channels formed in bipolar plates or in dedicated cooling plates. In this paper, a numerical method has been presented to study cooling and temperature distribution of a polymer membrane fuel cell stack. The heat flux on the cooling plate is variable. A three-dimensional model of fluid flow and heat transfer in cooling plates with 15 cm × 15 cm square area is considered and the performances of four different coolant flow field designs, parallel field and serpentine fields are compared in terms of maximum surface temperature, temperature uniformity and pressure drop characteristics. By comparing the results in two cases, the constant and variable heat flux, it is observed that applying constant heat flux instead of variable heat flux which is actually occurring in the fuel cells is not an accurate assumption. The numerical results indicated that the straight flow field model has temperature uniformity index and almost the same temperature difference with the serpentine models, while its pressure drop is less than all of the serpentine models. Another important advantage of this model is the much easier design and building than the spiral models.

Effect of Vibration on the Liquid Water Transport of PEM Fuel Cells

2009 ◽  
Author(s):  
Luis Breziner ◽  
Peter Strahs ◽  
Parsaoran Hutapea
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Water Transport ◽  
Liquid Water ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Cell Performance ◽  
Sinusoidal Vibration ◽  
Fuel Cell Performance ◽  
Liquid Water Transport

The objective of this research is to analyze the effects of vibration on the performance of hydrogen PEM fuel cells. It has been reported that if the liquid water transport across the gas diffusion layer (GDL) changes, so does the overall cell performance. Since many fuel cells operate under a vibrating environment –as in the case of automotive applications, this may influence the liquid water concentration across the GDL at different current densities, affecting the overall fuel cell performance. The problem was developed in two main steps. First, the basis for an analytical model was established using current models for water transport in porous media. Then, a series of experiments were carried, monitoring the performance of the fuel cell for different parameters of oscillation. For sinusoidal vibration at 10, 20 and 50Hz (2 g of magnitude), a decrease in the fuel cell performance by 2.2%, 1.1% and 1.3% was recorded when compared to operation at no vibration respectively. For 5 g of magnitude, the fuel cell reported a drop of 5.8% at 50 Hz, whereas at 20 Hz the performance increased by 1.3%. Although more extensive experimentation is needed to identify a relationship between magnitude and frequency of vibration affecting the performance of the fuel cell as well as a throughout examination of the liquid water formation in the cathode, this study shows that sinusoidal vibration, overall, affects the performance of PEM fuel cells.

Computer Models of Pem Fuel Cells for the Study of Transient Modes in Electrical Power Supply Complexes

2021 ◽  
Vol 64 (3) ◽  
pp. 60-67
Author(s):  
Ivan Vasyukov ◽  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Dynamic Response ◽  
Gradient Descent ◽  
Eddy Currents ◽  
Least Squares Method ◽  
Electrical Power ◽  
Computer Models ◽  
Pem Fuel Cells ◽  
Current Voltage

Static and dynamic computer models of fuel cells are considered. A static model is determined that most ac-curately reproduces the current-voltage characteristic of a real fuel cell. A method for tuning it according to the experimental I - V characteristic by the least squares method is proposed. A method for its adjustment ac-cording to the experimental I - V characteristic by the method of gradient descent is proposed. A modified elec-trical equivalent circuit of a fuel cell has been developed, which simulates its dynamic response, taking into ac-count the damping effect of eddy currents during operation of a stack of fuel cells on a pulse voltage converter. A method is proposed for determining the parameters of the model from the experimental oscillograms of the current and voltage of the stack. A universal model of a stack of fuel cells in LTspice has been developed, which makes it possible to simulate a dynamic response and, if necessary, simulate a real static I – V characteristic of the stack.

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