Microindentation Test for Assessing the Mechanical Properties of Silicone Rubber Exposed to a Simulated Polymer Electrolyte Membrane Fuel Cell Environment

2009 ◽  
Vol 6 (4) ◽  
Author(s):  
Jinzhu Tan ◽  
Y. J. Chao ◽  
Xiaodong Li ◽  
J. W. Van Zee
Keyword(s):  
Mechanical Properties ◽  
Fuel Cell ◽  
Polymer Electrolyte Membrane ◽  
Compressive Load ◽  
Pem Fuel Cells ◽  
Mechanical Degradation ◽  
Hertz Contact ◽  
Electrolyte Membrane ◽  
Elastomeric Materials ◽  
Hertz Contact Model

The elastomeric materials used as seals and gaskets in polymer electrolyte membrane (PEM) fuel cells are exposed to acidic environment, humid air, and hydrogen, and subjected to mechanical compressive load. The long-term mechanical and chemical stability of these materials is critical to both sealing and the electrochemical performance of the fuel cell. In this paper, mechanical degradation of two elastomeric materials, Silicone S and Silicone G, which are potential gasket materials for PEM fuel cells, was investigated. Test samples were subjected to various compressive loads to simulate the actual loading in addition to soaking in a simulated PEM fuel cell environment. Two temperatures, 80°C and 60°C, were selected and used in this study. Mechanical properties of the samples before and after exposure to the environment were studied by microindentation. Indentation load, elastic modulus, and hardness were obtained from the loading and unloading curves. Indentation deformation was studied using Hertz contact model. Dynamic mechanical analysis was conducted to verify the elastic modulus obtained by Hertz contact model. It was found that the mechanical properties of the samples changed considerably after exposure to the simulated environment over time. The temperature and the applied compressive load play a significant role in the mechanical degradation. The microindentation method is proved to provide a simple and efficient way to evaluate the mechanical properties of gasket materials.

Effect of Channel Geometry on Two-Phase Flow Structure in Fuel Cell Gas Channels

2011 ◽  
Author(s):  
Cody D. Rath ◽  
Satish G. Kandlikar
Keyword(s):  
Water Management ◽  
Fuel Cell ◽  
High Efficiency ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Ex Situ ◽  
Two Phase ◽  
Electrolyte Membrane ◽  
Excess Water

Water management issues continue to be a major concern for the performance of polymer electrolyte membrane (PEM) fuel cells. Maintaining the optimal amount of hydration can ensure that the cell is operating properly and with high efficiency. There are several components that can affect water management, however one area that has received increased attention is the interface between the gas diffusion layer (GDL) and the gas reactant channels where excess water has a tendency to build up and block reactant gasses. One key parameter that can affect this build up is the geometry of the microchannels. The work presented here proposes an optimal trapezoidal geometry which will aid in the removal of excess water in the gas channels. The Concus-Finn condition is applied to the channel surfaces and GDL to ensure the water will be drawn away from GDL surface and wicked to the top corner of the channel. An ex situ setup is designed to establish the validity of the Concus-Finn application. Once validated, this condition is then used to design optimal channel geometries for water removal in a PEM fuel cell gas channel.

scholarly journals Thermodynamic Study of Operation Properties Effect on Polymer Electrolyte Membrane Fuel Cells (PEM)

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ibrahim H Tawil ◽  
Farag M Bsebsu ◽  
Hassan Abdulkader
Keyword(s):  
Free Energy ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Gibbs Free Energy ◽  
Operating Temperature ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Heat Output ◽  
Enthalpy Of Reaction ◽  
Electrolyte Membrane

The thermodynamic analysis of PEM fuel cell energy production depends on the entropy and enthalpy of reaction with the changing of the operating temperatures that ranges between 50 and 100ºC, the electrical work done will be equal to the Gibbs free energy released. This paper presents a mathematical model of PEM fuel cells, based on physical-chemical procedures of the phenomena occurring inside the fuel cell, and it was theoretically studied the performance at different operation variables and conditions. The C++ program is designed to calculate all thermo-chemical parameters, i.e. enthalpy of formation, Gibbs free energy, work and efficiency for any type of fuel cells. The results are plotted as a function of fuel cell operating temperature. The results shows that the highest value of Gibbs energy is at the lowest operating temperature, and decreases gradually with increasing the temperature, the output voltage is determined by cell’s reversible voltage that arises from potential difference produced by chemical reaction and several voltage losses that occur inside a cell. In addition the results showed that the efficiency of this type of the fuel cells is much higher than the ideal Carnot’s efficiency, it changes between 82% to 85% depends on temperature operation. The heat output (required heat) from the fuel cell increases with increasing the operating temperature, this heat is used for many thermal applications such as buildings space heating.

Design and Construction of a Membrane Analysis System for Fuel Cell Humidification Applications

2013 ◽  
Author(s):  
Russell Borduin ◽  
Wei Li
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Optimal Operation ◽  
Transfer Rates ◽  
Electrolyte Membrane ◽  
Operation Conditions ◽  
Alternative Material ◽  
Analysis System ◽  
Water Transport Properties

Humidification membranes are vital to maintaining optimal operation conditions in polymer electrolyte membrane (PEM) fuel cells. Dry inlet air must be humidified to achieve an efficient reaction within the fuel cell. Nafion is currently the material of choice for humidification membranes due to its excellent water transport properties. However, the performance of Nafion comes at a high cost (∼ $1000/m2). There is a need to reduce membrane cost by developing an alternative material. The first step in developing a new membrane material is characterization of membrane performance. A humidification membrane measurement system was developed to determine vapor mass transfer rates through Nafion humidification membranes. The system creates a controlled environment where inlet water flow, air flow, temperature and pressure are regulated in order to measure the permeation rate of water through a membrane.

A Modeling Study of PEM Fuel Cell with Novel Catalyst Monolayers under Low Platinum Loading

2022 ◽  
Author(s):  
Jingtian Wu ◽  
Huiyuan Liu ◽  
Yujiang Song ◽  
Yun Wang
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Major Barrier ◽  
Electrolyte Membrane ◽  
Catalyst Layers ◽  
Novel Catalyst ◽  
Platinum Loading

Cost is a major barrier to commercialization of polymer electrolyte membrane (PEM) fuel cells. Catalyst layers (CLs) contribute to a major portion of PEM fuel cell cost due to the...

Minichannels in Polymer Electrolyte Membrane Fuel Cells

2004 ◽  
Author(s):  
Thomas A. Trabold
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Cross Sectional ◽  
Fuel Cell Performance ◽  
Electrolyte Membrane ◽  
Electrochemical Devices ◽  
Sectional Shape

This paper provides an overview of the application of minichannels, typically on the order of 1 mm hydraulic diameter, in the design of polymer electrolyte membrane (PEM) fuel cells. In these electrochemical devices, minichannels deliver reactant hydrogen and oxygen to the anode and cathode electrodes, respectively, while transporting product water out of the cell. The channels must be designed for low pressure drop, to avoid excessive parasitic power losses from gas handling equipment. However, the channels also need to operate in a flow regime in which the overall water balance in the fuel cell can be maintained. The various aspects of minichannel design, including size and cross-sectional shape, are discussed, with particular emphasis on fuel cell water management. In addition to reviewing these fundamental aspects of minichannel design, examples are given of new experimental tools currently under development which are applied to relate channel water transport and accumulation to fuel cell performance.

CFD Simulation of Flow Through the Reconstructed Microstructure of Fibrous Gas Diffusion Layer in a Polymer Electrolyte Membrane Fuel Cell

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Venkata Suresh Patnaikuni ◽  
Sreenivas Jayanti
Keyword(s):  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Diffusion Layer ◽  
Polymer Electrolyte Membrane ◽  
Effective Diffusion ◽  
Gas Diffusion Layer ◽  
Pem Fuel Cell ◽  
Pem Fuel Cells ◽  
Gas Diffusion ◽  
Electrolyte Membrane

AbstractThe gas diffusion layer (GDL) is one of the key components in a polymer electrolyte membrane (PEM) fuel cell. Generally it is a carbon-based fibrous medium that allows for the transport of electrons through the fibers and distributes the reactants through the void space to the catalyst layer in a PEM fuel cell. In the present work, a microstructure study of reactant transport is carried out by reconstructing the typical fibrous microstructure of the GDL and investigating the transport characteristics of the porous medium using computational fluid dynamics (CFD) simulations. The results confirm the applicability of Darcy’s law formulation for permeability determination and Bruggemann correction for calculation of effective diffusivity for typical conditions encountered in PEM fuel cells. Macroscopic material properties such as through-plane and in-plane permeabilities and effective diffusion coefficient are determined and compared against experimental values reported in the literature.

scholarly journals Composite Nafion-CaTiO3-δ Membranes as Electrolyte Component for PEM Fuel Cells

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2019
Author(s):  
Lucia Mazzapioda ◽  
Carmelo Lo Vecchio ◽  
Olesia Danyliv ◽  
Vincenzo Baglio ◽  
Anna Martinelli ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Large Scale ◽  
Polymer Electrolyte Membrane ◽  
Chemical Properties ◽  
Composite Membranes ◽  
Pem Fuel Cells ◽  
Calcium Titanate ◽  
Proton Exchange ◽  
Electrolyte Membrane ◽  
Direct Methanol

Manufacturing new electrolytes with high ionic conductivity has been a crucial challenge in the development and large-scale distribution of fuel cell devices. In this work, we present two Nafion composite membranes containing a non-stoichiometric calcium titanate perovskite (CaTiO3−δ) as a filler. These membranes are proposed as a proton exchange electrolyte for Polymer Electrolyte Membrane (PEM) fuel cell devices. More precisely, two different perovskite concentrations of 5 wt% and 10 wt%, with respect to Nafion, are considered. The structural, morphological, and chemical properties of the composite membranes are studied, revealing an inhomogeneous distribution of the filler within the polymer matrix. Direct methanol fuel cell (DMFC) tests, at 110 °C and 2 M methanol concentration, were also performed. It was observed that the membrane containing 5 wt% of the additive allows the highest cell performance in comparison to the other samples, with a maximum power density of about 70 mW cm−2 at 200 mA cm−2. Consequently, the ability of the perovskite structure to support proton carriers is here confirmed, suggesting an interesting strategy to obtain successful materials for electrochemical devices.

scholarly journals Advancement in Phosphoric Acid Doped Polybenzimidazole Membrane for High Temperature PEM Fuel Cells: A Review

2018 ◽  
Vol 23 (1) ◽  
Author(s):  
A. A. Tahrim ◽  
I. N. H. M. Amin
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Fuel Cell ◽  
Phosphoric Acid ◽  
Polymer Electrolyte ◽  
Polymer Electrolyte Membrane ◽  
Pem Fuel Cells ◽  
Green Technology ◽  
Electrolyte Membrane ◽  
Sulfonated Graphene

High-temperature polymer electrolyte membrane fuel cell as a sustainable green technology has been developed throughout the years as it provides several benefits compared to Nafion-based fuel cells (e.g., CO tolerance, improved kinetic and enhance water management). Polybenzimidazole which one of the best membrane candidates was extensively studied due to excellent properties to be used in high-temperature application. Impregnating polybenzimidazole with phosphoric acid are most commonly practised as an electrolyte membrane in the PEMFC. In this paper, recent advancement of the existing literature regarding work revolving polybenzimidazole to improve the performance of phosphoric acid doped polybenzimidazole membrane for high-temperature polymer electrolyte membrane fuel cell are reviewed. Notable works such as using aluminium containing silicate (Al-Si), silicon carbide whisker (mSiC) and sulfonated graphene oxide in the composite PBI derivatives were observed. Proton conductivity are recorded at 0.371, 0.271 and 0.280 S/cm, respectively.

Fluoroplastic- and Bio-Based Composites Materials for PEM Fuel Cells Bipolar Plates

2021 ◽  
Vol 899 ◽  
pp. 192-201
Author(s):  
Nikita Faddeev ◽  
Denis Tokarev ◽  
Tatyana A. Molodtsova ◽  
Maxim Belichenko ◽  
Victor Klushin
Keyword(s):  
Mechanical Properties ◽  
Fuel Cells ◽  
Plant Biomass ◽  
Polymer Electrolyte Membrane ◽  
Conductive Polymer ◽  
Conductive Filler ◽  
Pem Fuel Cells ◽  
Bipolar Plates ◽  
Colloidal Graphite ◽  
Electrolyte Membrane

Conductive polymer composite materials for polymer electrolyte membrane fuel cells bipolar plates have been successfully prepared from renewable plant biomass sources and copolymers of tetrafluoroethylene with vinylidenefluoride. The composites are based on various conductive fillers (natural, oxidized and colloidal graphite’s) and polymer binder (the 5-HMF synthesis by-product or fluoroplastic). The influences of type and content of binder and type of conductive filler on the mechanical properties and conductivity were investigated. Conductivity of the composites decreases with increasing of polymer content, but its mechanical properties changes inversely. Composite based on 5-HMF by-products (content 30 wt.%) and colloidal graphite as a filler meets the DOE requirements for a mechanical strength. Flexural and compressive strengths were 25 and 32 MPa, respectively. Composites based on fluoroplastic 32 (content 30 wt.%) and fluoroplastic 42 (content 20 wt.%) with colloidal graphite as a filler and fluoroplastic 42 (content 20 wt.%) with nature graphite have flexural strength values close to the target value of DOE and amounted to 24, 17 and 19 MPa, respectively. Interfacial contact resistance depends to a greater extent on the nature of the filler and is maximum for composites based on natural graphite. Composites based on fluoroplastic 42 at any filler content correspond to the requirements DOE ≤ 0.01 ohm∙cm2. Composite based on 5-HMF synthesis by-product (resin) and fluoroplastic with conductive filler (colloidal graphite) shows a great potential application as bipolar plates for PEMFCs.

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