Testing and Evaluation of Aluminum Coated Bipolar Plates of PEM Fuel Cells Operating at 70° C

2005 ◽  
Author(s):  
Yue Hung ◽  
Hazem Tawfik
Keyword(s):  
Single Cells ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
The Other ◽  
Metal Corrosion ◽  
Carbon Cloth ◽  
Bipolar Plates ◽  
Active Electrode ◽  
Corrosion Resistant ◽  
Aluminum Plates

Corrosion resistant metal treated bipolar plates with higher rigidity and electrical conductivity than graphite were developed and tested for PEM fuel cell applications. Six replicas of single cells were fabricated; two of graphite composites bipolar plates and the other four plates were coated aluminum. Two different high corrosion resistant coatings were used in this study and were applied to each pair of the metallic plates. An E-TEK Series 14-W MEA with carbon cloth GDL, thickness of Nafion <50 microns, <1mg/cm^2 total platinum content (anode & cathode) and 6.45 cm2 active electrode areas, was fitted to each cell and operated under identical conditions. The obtained data from the two graphite cells were averaged and plotted and the other aluminum cells’ data were similarly treated and plotted on the same graph for comparison. Generally, the metallic treated bipolar plate provided at least a 22% savings in hydrogen consumption in comparison to graphite. This is attributed to the lower bulk and surface contact resistance of the coated aluminum plates used in this study in relation to graphite. The results of the lifetime testing conducted at temperature of 70° C under loading condition ranging from 0 to 0.6 W that showed no indication of power degradation due to metal corrosion for at least 60 hours.

Corrosion Resistant, Lightweight, and Inexpensive Metallic Bipolar Plates With Excellent Manufacturability for PEM Fuel Cell Power Systems

2004 ◽  
Author(s):  
Yue Hung ◽  
K. M. El-Khatib ◽  
Hazem Tawfik
Keyword(s):  
Fuel Cell ◽  
Room Temperature ◽  
Experimental Testing ◽  
Single Cells ◽  
Pem Fuel Cell ◽  
The Other ◽  
Metal Corrosion ◽  
Bipolar Plates ◽  
Active Electrode ◽  
Corrosion Resistant

Corrosion resistant metal treated bipolar plates with higher rigidity and electrical conductivity than graphite were developed and tested for PEM fuel cell applications. Six replicas of single cells, three of which were made of graphite composites bipolar plates and the other three were made of the treated metallic plates. An Electrode Membrane Assembly (MEA) with 5.55 cm2 active electrode areas, double-sided electrodes, 0.3 mg/cm2 Pt loading and Nafion membrane 115 was fitted to each cell and operated under identical conditions. The experimental testing was conducted at room temperature 20°C. The obtained data from the three graphite cells were averaged and plotted and the other metallic cells’ data were similarly treated and plotted on the same graph for comparison. Generally, the metallic treated bipolar plate provided at least 12% saving in hydrogen consumption in comparison to graphite. This is attributed to the lower bulk and surface contact resistance of the metal used in this study in relation to graphite. The results of the lifetime testing, conducted at room temperature under variable loading showed no indication of power degradation due to metal corrosion for at least 1500 hours.

scholarly journals Design and Testing Criteria for Bipolar Plate Materials for Pem Fuel Cell Applications

1995 ◽  
Vol 393 ◽  
Author(s):  
R. L. Borup ◽  
N. E. Vanderborgh
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Development Program ◽  
Thermal Control ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Bipolar Plates ◽  
Corrosion Resistant ◽  
Testing Procedures

ABSTRACTBipolar plates for proton exchange membrane (PEM) fuel cells are currently under development. These plates separate individual cells of the fuel cell stack, and thus must be sufficiently strong to support clamping forces, be electrically conducting, be fitted with flow channels for stack thermal control, be of a low permeability material to separate safely hydrogen and oxygen feed streams, be corrosion resistant, and be fitted with distribution channels to transfer the feed streams over the plate surface. To date, bipolar plate costs dominate stack costs, and therefore future materials need to meet strict cost targets.A first step in the bipolar plate development program is an assessment of design constraints. Such constraints have been estimated and evaluated and are discussed here. Conclusions point to promising advanced materials, such as conductive, corrosion resistant coatings on metal substrates, as candidates for mass production of fuel cell bipolar plates. Possible candidate materials are identified, and testing procedures developed to determine suitability of various materials.

Dynamic Behavior and In-Situ Diagnostics of PEFCs

2006 ◽  
Author(s):  
Kaspar Andreas Friedrich ◽  
Till Kaz ◽  
Stefan Scho¨nbauer ◽  
Heinz Sander
Keyword(s):  
Fuel Cell ◽  
Density Distribution ◽  
Current Density ◽  
Single Cells ◽  
Current Density Distribution ◽  
Bipolar Plate ◽  
Life Cycles ◽  
Operating Conditions ◽  
Bipolar Plates

During fuel cell operation the electrochemical activity often is not homogenous over the electrode area. This may be caused by an non-uniform water content in the membrane, an inhomogeneous temperature distribution, and reactant gradients in the cell. Consequently a variation of the current density over the cell area occurs which tends to result in inferior performance. For in situ measurements of the current density distribution in fuel cell stacks a segmented bipolar plate was developed. The segmented bipolar plate was first tested in single cells with stack endplates to verify the function of all components. The tests showed that the measurement tool works very reliable and accurate. The insight in an operating fuel cell stack via current density distribution measurement is very helpful to investigate interactions between cells. Results can be used to validate models and to optimise stack components, e.g. flow field and manifold design, as well as to detect the best stack operating conditions. By applying segmented bipolar plates as sensor plates for stack system controls an improved performance, safe operation and longer life cycles can be achieved. The developed segmented bipolar plates with integrated current sensors were used to assemble a short stack consisting of 3 cells; each of them having an active area of 25cm2 divided into 49 segments. The design of the bipolar plate proofed very suitable for easy assembling of single cells and stacks. First measurement results show that different current distributions can appear in the cells and these can vary from cell to cell, depending on the operating conditions of the stack. Electrical coupling between the cells was investigated and found to be only marginal for the assembly used.

Corrosion-Resistant Tantalum Coatings for PEM Fuel Cell Bipolar Plates

2002 ◽  
Vol 756 ◽  
Author(s):  
Leszek Gladczuk ◽  
Chirag Joshi ◽  
Anamika Patel ◽  
Jim Guiheen ◽  
Zafar Iqbal ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Substrate Surface ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Body Centered Cubic ◽  
Bipolar Plates ◽  
Corrosion Resistant ◽  
Tantalum Coatings

ABSTRACTTantalum is a tough, corrosion resistant metal, which would be suitable for use as bipolar plates for proton exchange membrane (PEM) fuel cells, if it was not for its high weight and price. Relatively thin tantalum coatings, however, can be deposited on other inexpensive and lighter weight metals, such as aluminum and steel, providing a passive protection layer on these easily formed substrates. We have successfully deposited, high quality α (body-centered-cubic, bcc) and β (tetragonal) phase tantalum coatings that were a few micrometers thick by dc magnetron sputtering on steel and aluminum. The growth of the thermodynamically preferred body-centered-cubic (bcc) tantalum phase was induced by a choice of deposition conditions and substrate surface treatment. The microstructure and corrosion resistance of the α-phase in an environment approximately simulating the electrochemical conditions used in a PEM fuel cell were investigated under potentiodynamic conditions. Preliminary potentiostatic measurements of a β-phase sample are also presented.

Life-Limiting Aspects of the Corrosion of Metallic Bipolar Plates for PEM Fuel Cells

2008 ◽  
Vol 41-42 ◽  
pp. 469-475 ◽  
Author(s):  
Yan Wang ◽  
Derek O. Northwood
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Low Cost ◽  
Electronic Conductivity ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Metallic Materials ◽  
Bipolar Plates ◽  
Metallic Bipolar Plates

In proton exchange membrane fuel cells (PEMFCs), the bipolar plates supply the reactant gases through the flow channels to the electrodes and serve the purpose of electrochemically connecting one cell to another in the electrochemical cell stack. Requirements of the bipolar plate material are: high values of electronic conductivity; high values of thermal conductivity; high mechanical strength; impermeability to reactant gases; resistance to corrosion; and low cost of automated production. Metallic materials meet many of these requirements but the challenge has been in obtaining the required corrosion resistance. In the paper, six metallic materials were investigated as potential bipolar plate materials. The results showed that the corrosion rates were too high even for the most corrosion resistant metals (SS316L and grade 2 Ti), and that coatings would be required.

Modeling, Design and Fabrication of Non-Uniform Catalyst Layers for PEM Fuel Cells

2010 ◽  
Author(s):  
R. Roshandel
Keyword(s):  
Fuel Cells ◽  
Catalyst Layer ◽  
Current Density Distribution ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Electrochemical Kinetics ◽  
Carbon Cloth ◽  
Utilization Factor ◽  
Catalyst Layers ◽  
Plasma Sputtering

Catalyst layers are one of the most important parts of the PEM fuel cells and the cell performance is highly related to its structure. Catalyst layers are generally made by uniform distribution of catalyst on carbon cloth or carbon papers to form electrodes. In this paper, the idea of using non-uniform catalyst layer instead of common uniform catalyst layers is presented and simulated by a two-dimensional steady-state computational model. The model accounts for species transport, electrochemical kinetics, charge transport and current density distribution. A fuel cell test stand is designed and built to facilitate experimental validation of the model. Modeling results show that electrical current in catalyst layer is non-uniform, influenced by the channel-land patterns in bipolar plate geometry. Our simulations results also suggest that some non-uniform catalyst distribution patterns regarding to bipolar plate configuration will improve the performance of the whole catalyst layer by increasing catalyst utilization factor. Therefore, it is necessary to design non-uniform catalyst layers regarding to specific procedure. Plasma sputtering method is used to fabricate non-uniform catalyst layers. In this method, the platinum is deposited on the carbon cloth in the plasma-processing chamber. Indeed, an experimental procedure is presented to facilitate the fabrication of non-uniform catalyst layers by plasma sputtering.

scholarly journals Properties of graphite-stainless steel composite in bipolar plates in simulated anode and cathode environments of PEM fuel cells

2014 ◽  
Vol 32 (3) ◽  
pp. 487-497 ◽  
Author(s):  
Renata Włodarczyk
Keyword(s):  
Stainless Steel ◽  
Fuel Cells ◽  
Polymer Electrolyte Membrane ◽  
Surface Profile ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Good Choice ◽  
Bipolar Plates ◽  
Corrosion Properties ◽  
Steel Composite

AbstractThe use of a graphite-stainless steel composite as bipolar plates (BP) in polymer electrolyte membrane fuel cells (PEMFCs) has been evaluated. The study covers measurements of mechanical properties, microstructural examination, analysis of surface profile, wettability, porosity and corrosion resistance of the composite. The corrosion properties of the composite were examined in 0.1 mol·dm−3 H2SO4 + 2 ppm F− saturated with H2 or with O2 and in solutions with different pH: in Na2SO4+ 2 ppm F− (pH = 1.00, 3.00, 5.00) at 80 °C. The performed tests indicate that the graphite modified with stainless steel can be a good choice to be used as a bipolar plate in PEM fuel cells.

PEM Fuel Cell Bipolar Plate Reliability and Material Selection

2003 ◽  
Author(s):  
Michael J. Ajersch ◽  
Michael W. Fowler ◽  
Kunal Karan ◽  
Brant A. Peppley
Keyword(s):  
Fuel Cells ◽  
Life Cycle ◽  
Fuel Cell ◽  
Failure Modes ◽  
Material Selection ◽  
Pem Fuel Cell ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Cycle Performance ◽  
Bipolar Plates

The majority of the research on PEM fuel cells to date has been focused on assessing fuel cell behavior in the early stages of its life cycle. However, as widespread commercialization approaches, PEM fuel cells will be required to operate reliably for increasingly longer periods of time. It therefore also becomes equally important to characterize fuel cell performance at the end of its lifecycle. The reliability of a PEM fuel cell is dependent on the material properties, the manufacturing methods, and the design of its individual components. Among these components, the bipolar plates have received the least attention as a factor that may limit a fuel cell’s life cycle performance. Driven by the need for cost and weight reduction of fuel cell stacks, a significant amount of development work has been directed towards the development of new materials and designs for bipolar plates. Selection of an appropriate design and/or material for bipolar plates requires that reliability and durability data must be available, and that testing protocols appropriate and indicative of fuel cell operation be established. This paper provides a review fuel cell bipolar plate reliability and durability. Topics that will be addressed include bipolar plate functionality and design requirements, plate materials selection, plate failure modes. This is followed by a description of new bipolar plate reliability/durability test methods being developed at the CAMM Fuel Cell Research Group.

Metal-Foam Bipolar Plate for PEM Fuel Cells: Simulations and Preliminary Results

2018 ◽  
Vol 933 ◽  
pp. 342-350
Author(s):  
Yussed Awin ◽  
Nihad Dukhan
Keyword(s):  
Fuel Cells ◽  
Flow Field ◽  
Metal Foam ◽  
Bipolar Plate ◽  
Pem Fuel Cells ◽  
Unit Cell ◽  
Operating Conditions ◽  
Membrane Electrode ◽  
Computational Domain ◽  
Bipolar Plates

Bipolar plates in Proton Exchange Membrane fuel cells (PEMFC) distribute fuel and oxidant over the reactive sites of the membrane electrode assembly. In a stack, bipolar plates collect current, remove reaction products and manage water. They also separate neighboring cells and keep the oxidant and the fuel from mixing; they provide structural support to the stack. The plates are typically graphite with parallel or serpentine channels. The efficiency of a stack depends on the performance of the bipolar plates, which depends on the material and flow field design. The drawbacks of graphite include weight, fabrication inaccuracy, cost, porosity, and brittleness. Open-cell metal foam is investigated as a flow field/bipolar plate and compared to conventional graphite bipolar plates. The complex internal structure of the foam was modeled using an idealized unit cell based on a body center cube. This cell maintained the actual structural features of the foam. Clones of the idealized cell were virtually connected to each other to form the new bipolar plate. SolidWorks, and Auto-CAD were used to generate the unit cell and the computational domain, which was imported into ANSYS. Meshing of the domain produced than 350,000 elements, and 70,000 nodes. Appropriate boundary and operating conditions for PEMFC were applied, and the PEMFC module within ANSYS was used to obtain the temperature and flow distribution as well as the fuel cell performance. In comparison to conventional bipolar plates, results show that the cell current and voltage densities were improved, and temperature distribution on the membrane was even, and within the allowable limit. As importantly, there was a weight reduction of about 40% as a result of using metal foam as a bipolar plate.

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