Channel Dimensional Error Effect of Stamped Bipolar Plates on the Characteristics of Gas Diffusion Layer Contact Pressure for Proton Exchange Membrane Fuel Cell Stacks

2015 ◽  
Vol 12 (4) ◽  
Author(s):  
Diankai Qiu ◽  
Peiyun Yi ◽  
Linfa Peng ◽  
Xinmin Lai
Keyword(s):  
Fuel Cell ◽  
Contact Pressure ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Bipolar Plates ◽  
Dimensional Error ◽  
Plane Direction ◽  
Exchange Membrane

Thin metallic bipolar plates (BPPs) fabricated by stamping technology are regarded as promising alternatives to traditional graphite BPPs in proton exchange membrane (PEM) fuel cell. However, during the stamping process, dimensional error in terms of the variation in channel height is inevitable, which results in performance loss for PEM fuel cell stack. The objective of this study is to investigate the effect of dimensional error on gas diffusion layer (GDL) pressure characteristics in the multicell stacks. At first, parameterized finite element (FE) model of metallic BPP/GDL assembly is established, and the height of channels is considered as varying parameters of linear distribution according to measurements of actual BPPs. Evaluation methods of GDL contact pressure are developed by considering the pressure distribution in the in-plane and through-plane directions. Then, simulation of the assembly process for a series of multicell stacks is performed to explore the relation between dimensional error and contact pressure based on the evaluation methods. Influences of channel number, cell number, and clamping force on the constitutive relation are discussed. At last, experiments are conducted and pressure sensitive films are used to obtain the actual GDL contact pressure. The numerical results show the same trend as experimental results. This study illustrates that contact pressure of each cell layer is in severely uneven distribution for the in-plane direction, and pressure change is unavoidable for the through-plane direction in the multicell stack, especially for the first several cells close to the endplate. The methodology developed is beneficial to the understanding of the dimensional error effect, and it can also be applied to guide the assembling of PEM fuel cell stack.

Experimental Investigation of Proton Exchange Membrane Fuel Cell With Platinum and Nafion Along the In-Plane Direction

2020 ◽  
Author(s):  
Peng Cheng ◽  
Chasen Tongsh ◽  
Jinqiao Liang ◽  
Zhi Liu ◽  
Qing Du ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Cell Performance ◽  
Gradient Distribution ◽  
Plane Direction ◽  
Exchange Membrane

Abstract In this study, an experimental study has been performed to investigate the effect of in-plane distribution of Pt and Nafion in membrane electrode assembly (MEA) on proton exchange membrane (PEM) fuel cell. Two types of MEAs, such as the gradient and uniform distributions of Pt catalyst and Nafion, are compared under various operating conditions including cathode flow rate, MEA preparation method, Pt loading and relative humidity (RH). The catalyst ink is sprayed onto Nafion membrane or gas diffusion layer (GDL) through a pneumatic automatic spraying device manufactured by ourselves. MEA is prepared by hot pressing. The results show that as flow rate decreases, the MEA with gradient distribution will show a higher voltage at a high current density for catalyst coated membrane (CCM) method. For CCM method, gradient distribution can optimize cell performance under low cathode flow rate, but the optimization effect is weakened when flow rate is too low. Compared with CCM method, the gas diffusion electrode (GDE) method makes the difference value of Ohmic resistance between gradient and uniform distribution very larger, resulting in poor performance improvement. For GDE method, gradient distribution shows no optimization for cell performance under different Pt loadings and RH, but a smaller average Pt loading and fully-humidified reactants can reduce the performance distinction between uniform and gradient distribution. The gradient design of Pt and Nafion along the in-plane direction is a promising strategy to improve the performance of PEM fuel cell. Reasonably controlling the gradient distribution of Pt in the plane direction of cathode can reduce the amount of Pt catalysts and improve efficiency.

An Analytical Model for Contact Pressure Prediction Considering Dimensional Error of Stamped Bipolar Plate and Gas Diffusion Layer in Proton Exchange Membrane Fuel Cell Stack Assembly

2016 ◽  
Vol 13 (2) ◽  
Author(s):  
Linfa Peng ◽  
Diankai Qiu ◽  
Peiyun Yi ◽  
Xinmin Lai
Keyword(s):  
Fuel Cell ◽  
Pressure Distribution ◽  
Contact Pressure ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Bipolar Plate ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Dimensional Errors ◽  
Exchange Membrane

Contact pressure distribution between bipolar plate (BPP) and gas diffusion layer (GDL) has significant impact on performance and life time of proton exchange membrane (PEM) fuel cell. Most current studies for contact pressure prediction are based on finite-element analysis (FEA), requiring huge computation for the whole fuel cell assembly. Comparatively speaking, the more generalized and well-developed analytical methods are deficient in this field. The objective of this study is to propose a full-scale continuous equivalent model to predict GDL contact pressure effectively in the PEM fuel cell. Using the model, the nonuniform pressure distribution resulted from dimensional errors of metallic BPP and GDL could be obtained. First, a parameterized theoretical model of BPP/GDL assembly is established based on equivalent stiffness analysis of components, and definition methods of dimensional errors are proposed according to actual measurements and Monte Carlo simulation (MCS). Then, experiments are carried out to obtain the actual GDL contact pressure and the model results show good agreement with experimental results. At last, effects of dimensional errors are investigated. Acceptable assembly pressure for a given fuel cell is suggested based on the model. This model is helpful to understand the effect of the dimensional errors, and it also could be adopted to guide the manufacturing of BPP, GDL, and the assembling of PEM fuel cell.

Pore Structure Modeling of Flow in Gas Diffusion Layers of Proton Exchange Membrane Fuel Cells

2010 ◽  
Author(s):  
Zhongying Shi ◽  
Xia Wang
Keyword(s):  
Fuel Cell ◽  
Pore Structure ◽  
Proton Exchange Membrane ◽  
Cell Model ◽  
Transport Phenomena ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Structure Model ◽  
Exchange Membrane

The gas diffusion layer (GDL) in a proton exchange membrane (PEM) fuel cell has a porous structure with anisotropic and non-homogenous properties. The objective of this research is to develop a PEM fuel cell model where transport phenomena in the GDL are simulated based on GDL’s pore structure. The GDL pore structure was obtained by using a scanning electron microscope (SEM). GDL’s cross-section view instead of surface view was scanned under the SEM. The SEM image was then processed using an image processing tool to obtain a two dimensional computational domain. This pore structure model was then coupled with an electrochemical model to predict the overall fuel cell performance. The transport phenomena in the GDL were simulated by solving the Navier-Stokes equation directly in the GDL pore structure. By comparing with the testing data, the fuel cell model predicted a reasonable fuel cell polarization curve. The pore structure model was further used to calculate the GDL permeability. The numerically predicted permeability was close to the value published in the literature. A future application of the current pore structure model is to predict GDL thermal and electric related properties.

Pore Structure Modeling of Flow in Gas Diffusion Layers of Proton Exchange Membrane Fuel Cells

2012 ◽  
Vol 9 (2) ◽  
Author(s):  
Z. Shi ◽  
X. Wang
Keyword(s):  
Fuel Cell ◽  
Pore Structure ◽  
Proton Exchange Membrane ◽  
Cell Model ◽  
Transport Phenomena ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Structure Model ◽  
Exchange Membrane

The gas diffusion layer (GDL) in a proton exchange membrane (PEM) fuel cell has a porous structure with anisotropic and non-homogenous properties. The objective of this research is to develop a PEM fuel cell model where transport phenomena in the GDL are simulated based on GDL’s pore structure. The GDL pore structure was obtained by using a scanning electron microscope (SEM). GDL’s cross-section view instead of surface view was scanned under the SEM. The SEM image was then processed using an image processing tool to obtain a two-dimensional computational domain. This pore structure model was then coupled with an electrochemical model to predict the overall fuel cell performance. The transport phenomena in the GDL were simulated by solving the Navier-Stokes equation directly in the GDL pore structure. By comparing with the testing data, the fuel cell model predicted a reasonable fuel cell polarization curve. The pore structure model was further used to calculate the GDL permeability. The numerically predicted permeability was close to the value published in the literature. A future application of the current pore structure model is to predict GDL thermal and electric related properties.

Alloys that form conductive and passivating oxides for proton exchange membrane fuel cell bipolar plates

2004 ◽  
Vol 19 (6) ◽  
pp. 1723-1729 ◽  
Author(s):  
Neil Aukland ◽  
Abdellah Boudina ◽  
David S. Eddy ◽  
Joseph V. Mantese ◽  
Margarita P. Thompson ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Oxide Films ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Bipolar Plates ◽  
Concentrated Solutions ◽  
Exchange Membrane

During the operation of proton exchange membrane (PEM) fuel cells, a high-resistance oxide is often formed on the cathode surface of base metal bipolar plates. Over time, this corrosion mechanism leads to a drop in fuel cell efficiency and potentially to complete failure. To address this problem, we have developed alloys capable of forming oxides that are both conductive and chemically stable under PEM fuel cell operating conditions. Five alloys of titanium with tantalum or niobium were investigated. The oxides were formed on the alloys by cyclic voltammetry in solutions mimicking the cathode- and anode-side environment of a PEM fuel cell. The oxides of all tested alloys had lower surface resistance than the oxide of pure titanium. We also investigated the chemical durability of Ti–Nb and Ti–Ta alloys in more concentrated solutions beyond those typically found in PEM fuel cells. The oxide films formed on Ti–Nb and Ti–Ta alloys remained conductive and chemically stable in these concentrated solutions. The stability of the oxide films was evaluated; Ti alloys having 3% Ta and Nb were identified as potential candidates for bipolar plate materials.

Numerical Simulation of Droplet Emergence and Growth From Gas Diffusion Layers (GDLs) in Proton Exchange Membrane (PEM) Fuel Cell Flow Channels

2018 ◽  
Author(s):  
Jingru Benner ◽  
Mehdi Mortazavi ◽  
Anthony D. Santamaria
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Gas Diffusion Layers ◽  
Diffusion Layers ◽  
Flow Channels ◽  
Exchange Membrane ◽  
Over Time

Liquid water management is critical for Proton Exchange Membrane (PEM) fuel cell operation, as excessive humidity can lead to flooding and cell performance degradation. Water is produced in the cathode catalyst layer during the electrochemical reaction. If reactant gas streams become saturated, liquid water forms and must travel through anode and cathode Gas Diffusion Layers (GDLs) to reach flow channels for removal. Understanding the dynamic behavior of the droplet is critical to improve water removal strategies for PEM fuel cells. In this study a 3D, transient, two-phase model based on the Volume of Fluid (VOF) method was developed to study a single droplet in the gas channel. The formation, growth, and breakup of the droplet is tracked numerically and analyzed. The pressure drop across the droplet is monitored over time and compared with theoretical analysis. The droplet size and shape change over time for two different pore sizes are compared. The impact of various gases including air, helium, and hydrogen on droplet dynamics is presented. The viscous force and pressure force on the droplet and the drag coefficient are calculated.

Accelerated Numerical Test of Liquid Behavior Across Gas Diffusion Layer in Proton Exchange Membrane Fuel Cell Cathode

2008 ◽  
Vol 5 (4) ◽  
Author(s):  
Kui Jiao ◽  
Biao Zhou
Keyword(s):  
Fuel Cell ◽  
Water Flow ◽  
Diffusion Layer ◽  
Proton Exchange Membrane ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Fuel Cell Cathode ◽  
Exchange Membrane

Liquid water transport inside proton exchange membrane (PEM) fuel cells is one of the key challenges for water management in a PEM fuel cell. Investigation of the air-water flow patterns inside fuel cell gas flow channels with gas diffusion layer (GDL) would provide valuable information that could be used in fuel cell design and optimization. This paper presents an accelerated numerical investigation of air-water flow across a GDL with a serpentine channel on PEM fuel cell cathode by use of a commercial computational fluid dynamics software package FLUENT. Detailed flow patterns with air-water across the porous media were investigated and discussed.

scholarly journals Proton exchange membrane (PEM) fuel cell parametric study via mathematical modeling and numerical simulation.

2021 ◽  
Author(s):  
Rihab Jaralla
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Pem Fuel Cell ◽  
Gas Diffusion ◽  
Proton Exchange ◽  
Operating Pressure ◽  
Cell Models ◽  
Air Velocity ◽  
Air Inlet ◽  
Exchange Membrane

In the proton exchange membrane (PEM) fuel cell study, numerical analysis of complex and coupled multi-disciplinary processes involving the subjects of fluid dynamics, heat transfer, mass transport, and electrochemistry has been attempted over the past few decades. However, many resulting models are, in spite of fancier functionalities such as three-dimensionality, too complex to implement on account of the digital hardware requirement as well as computation time consumption. On the other hand, three-dimensional analytical models reported in literature look much simple, but they are embedded by a number of fairly unrealistic assumptions and, hence, lead to significantly weakened usability. In this thesis, a set of detailed two-dimensional non-isothermal computational models for PEM fuel cells in x-y and y-z planes are developed, which aims at the equivalency with the 3D PEM fuel cell model and, moreover, gains more insights with significantly reduced computational cost. The complete model consisting of the equations of continuity, momentum, energy, species concentrations, and electric potentials in different regions of a PEM fuel cell are numerically solved using the finite element method implemented into a commercial CFD (COMSOL) code. A comprehensive comparison with the experimental data has been performed to validate the 2D models developed in this study. On the basis of simulations of various flow and transport phenomena in an operational PEMFC, a systematic parametric study is conducted using the present developed PEM fuel cell models. A number of operating and design parameters are examined, including the operating pressure, ambient temperature, relative humidity, the porosity of the gas diffusion layer (GDL), the effective porosity of catalyst layer (CL), the porosity of membrane (M), the proton conductivity and the air inlet velocity at cathode side. The obtained results of this study revelaed that the membrane porosity, and air inlet velocity have considerable effects on the water content in the membrane, thus it is essential to select the proper values of these parameters to improve water management in the cell and avoid dehydration the membrane or flooding the electrode. Also, it is found that increasing air velocity at the inlet of the cathode gas channel has a significant effect on the temperature distribution in PEM fuel cell, as the temperature a noticeably dropped with higher inlet air velocity. The numerically results also found that with higher porosities of gas diffusion layers (GDLs) and catalyst layers (CLs), the performance of PEM fuel cell improved. In addition, it found that a higher performance can be achieved when fuel cell operated with reasonably higher operating temperature, operating pressure, proton conductivity and ensuring a full hydration of the reactants. The outcome of this study demonstrates that the present developed PEM fuel cell models can serve as a useful tool for understanding of transport and electrochemical phenomena in PEM fuel cell as well as for optimization of cell design and operating conditions.

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