Sintered Stainless Steel for Interconnectors for PEM Fuel Cell

2012 ◽  
Vol 706-709 ◽  
pp. 1047-1051
Author(s):  
Renata Włodarczyk
Keyword(s):  
Stainless Steel ◽  
Fuel Cells ◽  
Fuel Cell ◽  
New Technology ◽  
Bipolar Plate ◽  
Operating Conditions ◽  
Bipolar Plates ◽  
Fuel Cell Performance ◽  
Sintered Stainless Steel ◽  
Materials Used

Polymer electrolyte membrane fuel cell performance strongly depends on properties of the fuel cell stack bipolar plates (BPs). Bipolar plates are a key component of fuel cells. Functions of materials used for fuel cells include even distribution of gas fuel and air, conduction of electricity between the adjacent cells, heat transfer from the cell as well as prevention of gas leakage and cooldown. Due to multifunctionality of fuel cell plates, choice of materials used for plates is immensely difficult. This paper presents opportunities of application of a new technology of powder sintering for creation of parts for electricity and heat generators. Sintered stainless steel 316LHD was investigated as a candidate material for bipolar plate materials. 316L powders were compacted with the following load: 700MPa, 550MPa, and 200MPa, and then sintered at the temperature of 1250 °C in hydrogen medium. The main criterion for selection of a particular material for components of fuel cells is their corrosion resistance in operating conditions of hydrogen fuel cells. In order to determine resistance to corrosion in the environment of operation of fuel cells, potentiokinetic curves (as a function of temperature) were registered in synthetic solution 0.1M H2SO4 + 2 ppmF- at 80°C. The investigations also covered measurements of mechanical properties and microstructural testing of sinters with austenitic structure.

The Resistive Properties of Proton Exchange Membrane Fuel Cells With Stainless Steel Bipolar Plates

2010 ◽  
Vol 7 (4) ◽  
Author(s):  
Shuo-Jen Lee ◽  
Kung-Ting Yang ◽  
Yu-Ming Lee ◽  
Chi-Yuan Lee
Keyword(s):  
Stainless Steel ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Single Cells ◽  
Operating Conditions ◽  
Pure Oxygen ◽  
Bipolar Plates ◽  
Transfer Resistance ◽  
Treated Cell ◽  
Ohmic Resistance

In this research, electrochemical impedance spectroscopy is employed to monitor the resistance of a fuel cell during operation with different operating conditions and different materials for the bipolar plates. The operating condition variables are cell humidity, pure oxygen or air as oxidizer, and current density. Three groups of single cells were tested: a graphite cell, a stainless steel cell (treated and original), and a thin, small, treated stainless steel cell. A treated cell here means using an electrochemical treatment to improve bipolar plate anticorrosion capability. From the results, the ohmic resistance of a fully humidified treated stainless steel fuel cell is 0.28 Ω cm2. Under the same operating conditions, the ohmic resistance of the graphite and the original fuel cell are each 0.1 Ω cm2 and that of the small treated cell is 0.3 Ω cm2. Cell humidity has a greater influence on resistance than does the choice of oxidizer; furthermore, resistance variation due to humidity effects is more serious with air support. From the above results, fuel cells fundamental phenomenon such as ohmic resistance, charge transfer resistance, and mass transport resistance under different operating conditions could be evaluated.

Structural Analysis of Sintered Materials Used for Low-Temperature Fuel Cell Plates

2010 ◽  
Vol 638-642 ◽  
pp. 536-541 ◽  
Author(s):  
Agata Dudek ◽  
Renata Włodarczyk ◽  
Zygmunt Nitkiewicz
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
New Technology ◽  
Bipolar Plates ◽  
Efficient Operation ◽  
Equal Distribution ◽  
Gas Leakage ◽  
Powder Sintering ◽  
Gas Fuel ◽  
Materials Used

Bipolar plates (BPs) are key components of fuel cells. Functions of materials used for fuel cells include equal distribution of gas fuel and air, conduction of electricity between adjacent cells, heat transfer from the cell as well as prevention of gas leakage and cooldown. Moreover, the material must show particular corrosion resistance in cell’s working conditions. Meeting particular requirements or prevention of the abovementioned situations will enable efficient operation of cells. Due to multifunctional nature of fuel cell plates, choice of materials used for plates is immensely difficult. This paper presents opportunities of application of a new technology of powder sintering for creation of parts for electricity and heat generators. This work also presents analysis of structural and phase-related properties, porosity and strength tests.

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.

Experimental fuel cell performance analysis under different operating conditions and bipolar plate designs

2010 ◽  
Vol 35 (20) ◽  
pp. 11437-11447 ◽  
Author(s):  
Alfredo Iranzo ◽  
Miguel Muñoz ◽  
Eduardo López ◽  
Javier Pino ◽  
Felipe Rosa
Keyword(s):  
Fuel Cell ◽  
Performance Analysis ◽  
Bipolar Plate ◽  
Operating Conditions ◽  
Cell Performance ◽  
Fuel Cell Performance

scholarly journals Three-Dimensional Based Model of a Planar SOFC Fuelled by Biomass Gas

2006 ◽  
Author(s):  
Stefano Cordiner ◽  
Massimo Feola ◽  
Vincenzo Mulone ◽  
Fabio Romanelli
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Electrochemical Reaction ◽  
Electrical Response ◽  
Operating Conditions ◽  
Cell Performance ◽  
Gas Composition ◽  
Minimization Method ◽  
Fuel Cell Performance ◽  
Internal Reforming

Efficient and low polluting production of electricity and heat is an issue which cannot be postponed. Fuel cells, which convert the chemical energy stored in a fuel into electrical and thermal energy, are an efficient solution for such a problem. These devices rely on the combination of hydrogen and oxygen into water: oxygen is extracted from the air while hydrogen can be obtained from either fossil fuels or renewable sources. The use of biomass as hydrogen source in connection with fuel cells is an argument of particular interest, since high temperature gasification processes are actually utilized. Solid Oxide Fuel Cells (SOFC), working at high temperatures, have become therefore an interesting candidate to realize the internal reforming of the feed gas from a gasifier. The reforming reaction occurs at the anode of the SOFC, upstream and separated from the fuel cell reaction. The section of the anode where reforming occurs is adjacent to the section where electrochemical reaction occurs. So, heat produced by the electrochemical reaction can be transferred internally with minimal losses. Simulation models of the performance of SOFC stacks and biomass gasifiers are useful to visualize temperature, current and concentration distributions, which are difficult to measure by experimental techniques, allowing the definition of optimal choices in terms of geometries and operating conditions. In this work, an analysis of a SOFC coupled with a biomass gasifier is performed. The objective of this study is the identification of the main effects of the operating conditions on the fuel cell performance in terms of efficiency, and the distribution of the main electro-thermal-fluid-dynamics variables, namely current and temperature. A gasifier model has been implemented to calculate the equilibrium compositions using the Gibbs free energy minimization method. The obtained results are directly used to estimate the inlet gas composition for the SOFC. The SOFC has been modelled by a 3D approach (FLUENT), which solves the energy and mass transport and the internal reforming, coupled with a 0D electrolyte model which, starting from the local information in terms of gas composition, temperature and pressure, is able to predict the fuel cell performance in terms of electrical response and mass-energy fluxes. The whole model has been applied to the analysis of an integrated SOFC-gasifier system to address a planar SOFC response by varying the gasifier operating conditions and the global system performance.

CFD Simulations of Flow and Pressure Distributions in Column Flow Type Fuel Cells

2006 ◽  
Author(s):  
Paul Ridenour ◽  
Zhigi Ma ◽  
Naresh Kumar Selvarasu ◽  
Eugene S. Smotkin ◽  
Chenn Q. Zhou
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Flow Rate ◽  
New Technology ◽  
Volumetric Flow Rate ◽  
Electrical Energy ◽  
Pressure Drops ◽  
Fuel Cell Performance ◽  
Pressure Distributions ◽  
Flow Channels

Fuel cells are a growing new technology that can be applied in order to harness electrical energy out of hydrogen and hydrated air. When testing these devices however, pressure drops along the apparatus are strongly discouraged due to the fluctuation in gas volumetric flow rate that they incur. The design of the flow channels is critical to the fuel cell performance and water management. In this research, computational fluid dynamics (CFD) is used to analyze the gas manifold and a column channel inside of a fuel cell. The effect of the flow channel parameters on the flow rate and pressure drops are investigated to provide useful information to optimize the design of flow channels.

Investigating the Use of Stamped Metal Foils as Bipolar Plates in PEM Fuel Cell Stacks

2008 ◽  
Author(s):  
Rachel T. Backes ◽  
David T. McMillan ◽  
Andrew M. Herring ◽  
John R. Berger ◽  
John A. Turner ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fuel Cell ◽  
Flow Field ◽  
Thin Sheet ◽  
Pem Fuel Cell ◽  
Bipolar Plate ◽  
Steel Plates ◽  
Bipolar Plates ◽  
Fuel Cell Stack ◽  
Serpentine Flow Field

The process of stamping stainless steel bipolar plates is developed from initial plate design through manufacturing and use in a fuel cell stack. A stamped design incorporating a serpentine flow field for the cathode and an interdigitated flow field for the anode is designed. This bipolar plate consists of only one piece of thin stainless steel sheet. The process of rubber-pad stamping was chosen to reduce shearing of the thin sheet. Dies were designed and made. Stainless steel plates were stamped, but stress were higher than anticipated and die failure was observed. The plates were tested both in-situ and by doing simulated fuel cell testing. Although sealing was an issue due to lack of proper gaskets and endplates, tests determined that the stamped bipolar plates will work in a PEM fuel cell stack. Dies were redesigned to improve durability. Gaskets and endplates were designed to complete the stack construction.

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.

Simulation and Testing of Polymer Electrolyte Membrane Fuel Cell Bipolar Plates Fabricated by Selective Laser Sintering

2012 ◽  
Author(s):  
M. Wu ◽  
M. C. Leu ◽  
N. Guo
Keyword(s):  
Fuel Cell ◽  
Flow Field ◽  
Polymer Electrolyte Membrane ◽  
Selective Laser Sintering ◽  
Bipolar Plate ◽  
Effect Of Temperature ◽  
Bipolar Plates ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane ◽  
Simulation Results

Polymer Electrolyte Membrane (PEM) fuel cell converts directly electrochemical energy into electricity. Flow channels in bipolar plates, a critical component of fuel cell, were designed, simulated and tested. The bipolar plate used a mixture of graphite materials, and was fabricated using a Selective Laser Sintering (SLS) process. The fabricated green parts were carbonized at high temperatures and converted into brown parts. Infiltration of resin was used to enhance the electric conductivity and strength of the bipolar plate. Finite element simulations were performed to investigate the state of species (hydrogen, oxygen) in the channels and Gas Diffusion Layers (GDLs) for four flow field designs including parallel, serpentine, single Hilbert and composite Hilbert. The simulation results were used to obtain the polarization curves and the relationships between stack power and current density, and to discuss the effect of temperature on fuel cell performance. Experiments were conducted to validate the simulation results on voltage and power vs. current density and the effect of temperature on fuel cell performance for the different flow field designs.

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