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

2018 ◽  
Vol 933 ◽  
pp. 342-350
Author(s):  
Yussed Awin ◽  
Nihad Dukhan

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.

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3203 ◽  
Author(s):  
Oluwatosin Ijaodola ◽  
Emmanuel Ogungbemi ◽  
Fawwad Nisar. Khatib ◽  
Tabbi Wilberforce ◽  
Mohamad Ramadan ◽  
...  

Environmental concerns of greenhouse gases (GHG) effect from fossil commodities and the fast increase in global energy demand have created awareness on the need to replace fossil fuels with other sources of clean energy. PEM fuel cell (PEMFC) is a promising source of energy to replace fossil fuels. The commercialization of the cell depends on its price, weight and mechanical strength. Bipolar plates are among the main components of PEMFC which perform some significant functions in the fuel cell stack. Metal bipolar plate is considered by the research community as the future material for fuel cells. However, surface coating is required for metals to enhance its corrosion resistance, hydrophilicity and interfacial contact resistance (ICR) in PEM fuel cells. Open pore cellular metal foam (OPCMF) materials have been used to replace the conventional flow field channel in recent times due to its low electrical resistance, high specific area and high porosity; however, it endures the same corrosion problem as the metallic bipolar plate. This investigation offers an overview on different types of bipolar plates and techniques in coating metallic bipolar platse and open pore metal foam as flow field channel materials to improve the corrosion resistance which will eventually increase the efficiency of the fuel cell appreciably.


2015 ◽  
Vol 40 (5) ◽  
pp. 2303-2311 ◽  
Author(s):  
Muhittin Bilgili ◽  
Magdalena Bosomoiu ◽  
Georgios Tsotridis

Author(s):  
Daniel J. Fenton ◽  
Jeffrey J. Gagliardo ◽  
Thomas A. Trabold

To achieve optimal performance of proton exchange membrane (PEM) fuel cells, effective water management is crucial. Cells need to be fabricated to operate over wide ranges of current density and cell temperature. To investigate these design and operational conditions, the present experiment utilized neutron radiography for measurement of in-situ water volumes of operating PEM fuel cells under varying operating conditions. Fuel cell performance was found to be generally inversely correlated to liquid water volume in the active area. High water concentrations restrict narrow flow field channels, limiting the reactant flow, and causing the development of performance-reducing liquid water blockages (slugs). The analysis was performed both quantitatively and qualitatively to compare the overall liquid water volume within the cell to the flow field geometry. The neutron image analysis results revealed interesting trends related to water volume as a function of time. At temperatures greater than 25°C, the total liquid water volume at start-up in the active area was the lowest at 1.5 A/cm2. At 25°C, 0.1 A/cm2 performed with the least amount of liquid water accumulation. However, as the reaction progressed at temperatures above 25°C, there was a crossover point where 0.1 A/cm2 accumulated less water than 1.5 A/cm2. The higher the temperature, the longer the time required to reach this crossover point. Results from the current density analysis showed a minimization of water slugs at 1.5 A/cm2, while the temperature analysis showed unexpectedly that, independent of current density, the condition with lowest water volume was always 35°C.


2008 ◽  
Vol 41-42 ◽  
pp. 469-475 ◽  
Author(s):  
Yan Wang ◽  
Derek O. Northwood

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.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2831 ◽  
Author(s):  
Min Soo Kim ◽  
Joo Hee Song ◽  
Dong Kyu Kim

This study presents an economical conditioning method for polymer electrolyte membrane (PEM) fuel cells through a parametric study investigating the factors affecting online conditioning methods. First, we compared the operating conditions between constant current (CC) mode and constant voltage (CV) mode conditioning to understand the effects of current and potential differences on conditioning. We found that CV mode conditioning is at least one hour faster at the same load. This is because unlike CV mode conditioning, which has a constant load over the entire range of the membrane electrode assembly (MEA), CC mode conditioning features current flow through the existing passage of the pre-activated triple phase boundary of the MEA so that the electronic load is not entirely used in the conditioning process. Second, the optimization of CV mode conditioning was conducted by controlling the conditioning temperature. Lastly, the economics of the proposed method were analyzed by comparing it with existing conditioning methods. Using this optimal conditioning method can reduce the consumption of hydrogen during conditioning by ~87.5% compared to previous methods. The findings from this study provide the means to lower the actual production cost of fuel cells, thereby ensuring market access.


2014 ◽  
Vol 32 (3) ◽  
pp. 487-497 ◽  
Author(s):  
Renata Włodarczyk

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.


Author(s):  
Michael J. Ajersch ◽  
Michael W. Fowler ◽  
Kunal Karan ◽  
Brant A. Peppley

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.


Sign in / Sign up

Export Citation Format

Share Document