scholarly journals Investigation of Bipolar Plate Forming with Various Die Configurations by Magnetic Pulse Method

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 453 ◽  
Author(s):  
Wang ◽  
Wang
Keyword(s):  
Major Part ◽  
Capacitor Bank ◽  
Pulse Method ◽  
Bipolar Plate ◽  
Magnetic Pulse ◽  
Percentage Increase ◽  
Bipolar Plates ◽  
Draft Angle ◽  
Die Surface ◽  
Primary Current

Bipolar plates are a major part of fuel cells, which are a clean and recyclable energy source. This study was carried out with two dies for a bipolar plate forming investigation with the magnetic pulse method: a bipolar plate die and a 10-channel die. With the bipolar plate die, the forming of bipolar plates with a Cu110 sheet and a Grade 2 Ti sheet indicated that the bipolar plate die needed optimization for a full replication. The obtained maximum average depth percentage was 86% for a Cu110 sheet, while it was 54% for a Grade 2 Ti sheet in this study. A further increase of the depth percentage is possible but requires a much higher capacitor bank energy. The increase of the capacitor bank energy would result in severe tearing, while the depth percentage increase was little. The primary current and flyer velocity were measured at various capacitor bank energies. With the 10-channel die, the die parameters’ effect on metal sheet forming was investigated with a Cu110 sheet and an SS201 sheet. The draft angle had a significant effect on the replication of the die surface. The full replication was achieved for channels with proper parameters with both a Cu110 sheet and an SS201 sheet. Therefore, the bipolar plate die could be optimized based on the 10-channel die results.

scholarly journals About mathematical simulation of processes for high-speed loading of materials on Department of Physical Mechanics of St. Petersburg State University

2020 ◽  
Vol 65 (4) ◽  
pp. 699-713
Author(s):  
Victor A. Morozov ◽  
◽  
Vsevolod I. Bogatko ◽  
Andrey B. Yakovlev ◽  
◽  
...  
Keyword(s):  
Mathematical Simulation ◽  
High Speed ◽  
Surface Region ◽  
Pulse Method ◽  
Magnetic Pulse ◽  
State University ◽  
Natural Experiments ◽  
Near Surface ◽  
Metal Rings ◽  
Physical Mechanics

The researches of shock-wave processes in the constructional materials are actual, but carrying out of natural experiments is extremely inconvenient and expensive, and sometimes it is even impossible to replicate. Therefore basically all researches of these problems are reduced to various cases of simulation of processes for high-speed loading of materials in the laboratory circumstances. In the paper we consider following directions of mathematical simulation of processes for high-speed loading of materials that were made on department of physical mechanics of St. Petersburg State University: the simulation of shock-loaded media by using of dynamics of dislocations; the simulation of high-speed loading of media with the account of the relaxation phenomena in a near-surface region; the simulation of propagation of the short elastoplastic impulse in medium under the condition of influence of a weak magnetic field; the generation of mathematical models of deformation and destruction of thin metal rings by a magnetic-pulse method; the simulation of crack propagation during the short-term pulse loading.

scholarly journals Properties of a Plasma-Nitrided Coating and a CrNx Coating on the Stainless Steel Bipolar Plate of PEMFC

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 183 ◽  
Author(s):  
Meiling Xu ◽  
Shumei Kang ◽  
Jinlin Lu ◽  
Xinyong Yan ◽  
Tingting Chen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Bipolar Plate ◽  
Working Environment ◽  
Stainless Steel Surface ◽  
Bipolar Plates ◽  
Better Than

PEMFC are considered to be the most promising for automotive energy because of their good working effect, low temperature, high efficiency, and zero pollution. Stainless steel as a PEMFC bipolar plate has unparalleled advantages in strength, cost, and processability, but it is easy to corrode in a PEMFC working environment. In order to improve the corrosion resistance, the surface modification of 316L stainless steel is a feasible solution for PEMFC bipolar plates. In the present study, the plasma-nitrided coating and CrNx coating were prepared by the plasma-enhanced balanced magnetron sputtering technology on the 316L stainless steel surface. The microstructures, phase compositions, and corrosion resistance behavior of the coatings were investigated. The corrosion behavior of the prepared plasma-nitrided coating and CrNx coating was investigated by potentiodynamic polarization, potentiostatic polarization, and electrochemical impedance spectroscopy (EIS) in both cathodic and anodic environments. The experimental results show that corrosion resistance of the CrNx coating was better than the plasma-nitrided coating. It was indicated that the technology process of nitriding first and then depositing Cr was better than nitriding only.

scholarly journals A Review of Metallic Bipolar Plates for Proton Exchange Membrane Fuel Cells: Materials and Fabrication Methods

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Shahram Karimi ◽  
Norman Fraser ◽  
Bronwyn Roberts ◽  
Frank R. Foulkes
Keyword(s):  
Proton Exchange Membrane ◽  
Cost Effective ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Reaction Products ◽  
Bipolar Plates ◽  
Metallic Bipolar Plates ◽  
Density Graphite ◽  
Feasible Alternative ◽  
Exchange Membrane

The proton exchange membrane fuel cell offers an exceptional potential for a clean, efficient, and reliable power source. The bipolar plate is a key component in this device, as it connects each cell electrically, supplies reactant gases to both anode and cathode, and removes reaction products from the cell. Bipolar plates have been fabricated primarily from high-density graphite, but in recent years, much attention has been paid to developing cost-effective and feasible alternative materials. Two different classes of materials have attracted attention: metals and composites. This paper offers a comprehensive review of the current research being carried out on metallic bipolar plates, covering materials and fabrication methods.

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.

Numerical Simulation of Accumulative Forming Bipolar Plates of Fuel Cell

2010 ◽  
Vol 136 ◽  
pp. 10-13
Author(s):  
Zhen Ying Xu ◽  
Jing Jing Wang ◽  
Sheng Ding ◽  
Wu Wen ◽  
Yun Wang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Element Model ◽  
Bipolar Plate ◽  
Forming Limit ◽  
Bipolar Plates ◽  
Thickness Change ◽  
Flow Channels ◽  
Starting Point ◽  
Micro Flow ◽  
Maximal Magnitude

The bipolar plate is the key part in the fuel cell. It is difficult to produce the micro flow channel of bipolar plates with high accuracy. In order to solve this problem, we present one new forming techniques, accumulative forming, for the fabrication of micro flow channels. With the utilization of the software ABAQUS, finite element model of the bipolar plate with the 20mm×20mm×0.2mm is developed to simulate the accumulative forming and obtain the forming rules. The simulation results are about the plate’s thickness change and deformation. It shows that the thickness reduction decreases gradually from the center of the channel to the outside with the maximal magnitude in the starting point of accumulative forming. The maximum thinning ratio is 15.85%, which is in the forming limit scope. The simulation demonstrates the feasibility of the accumulative forming and good formability.

The Cylindrical Structure of Metallic Bipolar Plates for Proton Exchange Membrane Fuel Cell

2011 ◽  
Vol 228-229 ◽  
pp. 1029-1034
Author(s):  
Jian Lan ◽  
Chen Ni ◽  
Lin Hua
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Battery Life ◽  
Membrane Electrode ◽  
Bipolar Plates ◽  
Forming Process ◽  
Cylindrical Structure ◽  
Exchange Membrane

As a key component of proton exchange membrane fuel cell (PEMFC), the bipolar plate’s performance will directly affect the power output and battery life of the fuel cell. The conventional metallic bipolar plate is prone to warp, and has large flatness error with residual stress induced by forming process. This will result in contacting incompletely with membrane electrode assemblies (MEA) and lower fuel cell efficiency. A cylindrical structure of the PEMFC metallic polar plate is proposed to improve its stiffness and to reduce assembling error of the fuel cell. The polar plate features, which were originally designed on a flat surface, are projected onto the cylindrical surface with a certain curvature. Two cylindrical polar plates are welded together to become a bipolar plate. The finite element method is applied to compare the stiffness of the conventional and cylindrical polar & bipolar plates. The cylindrical bipolar plate has better stiffness and anti-warping than the conventional bipolar plate. The feasibility of the cylindrical structure is verified by experiment and provides a new idea for the improvement of the bipolar plate and fuel cell stack.

scholarly journals Design and Modeling of Metallic Bipolar Plates for a Fuel Cell Range Extender

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5484
Author(s):  
Uwe Reimer ◽  
Ekaterina Nikitsina ◽  
Holger Janßen ◽  
Martin Müller ◽  
Dieter Froning ◽  
...  
Keyword(s):  
Mobile Applications ◽  
Bipolar Plate ◽  
Cathode Side ◽  
Bipolar Plates ◽  
Metallic Bipolar Plates ◽  
Range Extender ◽  
Low Weight ◽  
Metallic Bipolar Plate ◽  
Dry Conditions

Fuel cells, designed for mobile applications, should feature compact and low-weight designs. This study describes a design process that fulfills the specific needs of target applications and the production process. The key challenge for this type of metallic bipolar plate is that the combination of two plates creates three flow fields, namely an anode side, a cathode side, and a coolant. This illustrates the fact that each cell constitutes an electrochemical converter with an integrated heat exchanger. The final arrangement is comprised of plates with parallel and separate serpentine channel configurations. The anode and cathode sides are optimized for operation under dry conditions. The final plate offers an almost perfect distribution of coolant flow over the active area. The high quality of this distribution is almost independent of the coolant mass flow, even if one of the six inlet channels is blocked. The software employed (OpenFOAM and SALOME) is freely available and can be used with templates.

scholarly journals Corrosion Behavior and Conductivity of TiNb and TiNbN Coated Steel for Metallic Bipolar Plates

2019 ◽  
Vol 9 (12) ◽  
pp. 2568 ◽  
Author(s):  
Kun Shi ◽  
Xue Li ◽  
Yang Zhao ◽  
Wei-Wei Li ◽  
Shu-Bo Wang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Proton Exchange Membrane ◽  
Electronic Conductivity ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Carbon Paper ◽  
Bipolar Plates ◽  
Metallic Bipolar Plates ◽  
Metallic Bipolar Plate ◽  
Interfacial Contact Resistance

To improve corrosion resistance and electronic conductivity of bipolar plates for proton exchange membrane fuel cell (PEMFC), coatings of TiNb and TiNbN on 316L stainless steel (SS) were prepared by magnetron sputtering. X-ray diffraction (XRD) measurements confirmed the existence of metallic nitrides in the TiNbN coating. Scanning electron microscope (SEM) tests showed that the deposited coatings provided smooth surfaces. Further electrochemical measurements indicated that the corrosion resistance of TiNb coating was significantly higher than that of substrate. At 0.19 V vs MSE, the long-term stabilized current density of TiNb/316L SS was lower than 1 μA·cm−2. The interfacial contact resistance (ICR) values between coating and carbon paper suggested that TiNb and TiNbN films had better contact conductivity than 316L SS substrate. In conclusion, TiNb coated 316L SS metallic bipolar plate material is a promising option for PEMFC.

Die Design of Aluminum Bipolar Plate Fabrication by Stamping Process and its Investigation

2012 ◽  
Vol 445 ◽  
pp. 108-113 ◽  
Author(s):  
H.J. Kwon ◽  
Y.P. Jeon ◽  
Chung Gil Kang
Keyword(s):  
Aluminum Alloy ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Bipolar Plate ◽  
Proton Exchange ◽  
Die Design ◽  
Bipolar Plates ◽  
Micro Channels ◽  
The Cost ◽  
Exchange Membrane

A Proton Exchange Membrane Fuel Cell (PEMFC) is a type of fuel cell being developed for automotive applications as well as for stationary fuel cell applications and portable fuel cell applications. Its performance such as power density can be improved by the use of the bipolar plate with a new lightweight material which is one of core components making up PEMFC stack. Aluminum alloy has good mechanical properties not only in terms of density, electrical resistivity and thermal conductivity, but also in terms of corrosion resistant compared with stainless steel and graphite composites bipolar plate. Furthermore, the use of aluminum for a bipolar plate reduces simultaneously the cost and weight of it, and it contributes to the ease of machining. For these reason, an aluminum alloy is selected in this study. This study presents the feasibility of the simulation for the development of aluminum bipolar plates that consists of multi array micro channels. The analytical solutions obtained by the simulation are validated by the comparison with the experimental results. From the results, it is ensured that the stamping processes for the bipolar plate could be predicted and designed by the results of the by FE-Simulation.

DETECTION OF INTEGRITY DEFECTS IN ALUMINUM SPECIMENS BY THE MAGNETIC PULSE METHOD

2019 ◽  
Vol 85 (4) ◽  
pp. 28-32
Author(s):  
Vladimir V. Pavlyuchenko ◽  
Elena S. Doroshevich
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Pulse Method ◽  
Magnetic Pulse ◽  
Magnetic Field Direction ◽  
Magnetic Carrier ◽  
Electric Voltage ◽  
Useful Signal ◽  
Measurement Plane ◽  
Aluminum Plates

Experimental time dependences of the electric voltage U(t), taken from the induction magnetic head when scanning it with a magnetic carrier with magnetic field records of artificial defects of the integrity (slits) with a width of (1.0 - 10.0) x 10-5  m in aluminum plates from 1.5 x 10-6 to 2.0 x 10-3 m are presented. On the magnetic carrier the magnetic fields of the defects that occur when aluminum plates are exposed to a pulse of magnetic field of plane inductor (action time of about 1.0 x 10-4 sec). Dependences of U(t) for different depths of bedding of the defects and thickness of the layer of the material above them in the specified ranges of influences are obtained. In this case, distributions of instantaneous magnetic fields are recorded on the surface area of objects of the order of 1.0 x 10-3 m2 with a resolution in the measurement plane of 1.0 x 10-8 m2. The novelty of the method consists in determination of the amplitude of the main pulse of the field and build up time, the shape of the leading and trailing edges, as well as the amplitude, build up time, the number and polarity of the outliers of magnetic field, direction of the applied field, operations of smoothing, calculation, separation of the useful signal and operations of recognition of the defect information recorded on the magnetic medium with analysis of the dependences U(t). The developed method for controlling objects from electrically conductive materials makes it possible to increase several times the accuracy and speed of the control of the integrity defects in diamagnetic and paramagnetic metals.

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