Experimental Methods and Data Analyses for Polymer Electrolyte Fuel Cells

Experimental Methods and Data Analyses for Polymer Electrolyte Fuel Cells PDF Author:
Publisher:
ISBN:
Category : Fuel cells
Languages : en
Pages : 138

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Book Description

Experimental Methods and Data Analyses for Polymer Electrolyte Fuel Cells

Experimental Methods and Data Analyses for Polymer Electrolyte Fuel Cells PDF Author:
Publisher:
ISBN:
Category : Fuel cells
Languages : en
Pages : 138

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Book Description


PEM Fuel Cell Electrocatalysts and Catalyst Layers

PEM Fuel Cell Electrocatalysts and Catalyst Layers PDF Author: Jiujun Zhang
Publisher: Springer Science & Business Media
ISBN: 1848009364
Category : Technology & Engineering
Languages : en
Pages : 1147

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Book Description
Proton exchange membrane (PEM) fuel cells are promising clean energy converting devices with high efficiency and low to zero emissions. Such power sources can be used in transportation, stationary, portable and micro power applications. The key components of these fuel cells are catalysts and catalyst layers. “PEM Fuel Cell Electrocatalysts and Catalyst Layers” provides a comprehensive, in-depth survey of the field, presented by internationally renowned fuel cell scientists. The opening chapters introduce the fundamentals of electrochemical theory and fuel cell catalysis. Later chapters investigate the synthesis, characterization, and activity validation of PEM fuel cell catalysts. Further chapters describe in detail the integration of the electrocatalyst/catalyst layers into the fuel cell, and their performance validation. Researchers and engineers in the fuel cell industry will find this book a valuable resource, as will students of electrochemical engineering and catalyst synthesis.

Proton Exchange Membrane Fuel Cells 9

Proton Exchange Membrane Fuel Cells 9 PDF Author: T. Fuller
Publisher: The Electrochemical Society
ISBN: 1566777380
Category : Fuel cells
Languages : en
Pages : 2100

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Book Description
This issue of ECS Transactions is devoted to all aspects of research, development, and engineering of proton exchange membrane (PEM) fuel cells and attacks, as well as low-temperature direct-fuel cells. The intention of the symposium is to bring together the international community working on the subject and to enable effective interactions between the research and engineering communities. This issue is sold as a two-part set.

Polymer Electrolyte Fuel Cells

Polymer Electrolyte Fuel Cells PDF Author: Alejandro A. Franco
Publisher: CRC Press
ISBN: 9814364401
Category : Science
Languages : en
Pages : 608

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Book Description
This book focuses on the recent research progress on the fundamental understanding of the materials degradation phenomena in PEFC, for automotive applications. On a multidisciplinary basis, through contributions of internationally recognized researchers in the field, this book provides a complete critical review on crucial scientific topics related

PEM Fuel Cell Diagnostic Tools

PEM Fuel Cell Diagnostic Tools PDF Author: Haijiang Wang
Publisher: CRC Press
ISBN: 1439839190
Category : Science
Languages : en
Pages : 580

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Book Description
PEM Fuel Cell Diagnostic Tools presents various tools for diagnosing PEM fuel cells and stacks, including in situ and ex situ diagnostic tools, electrochemical techniques, and physical/chemical methods. The text outlines the principles, experimental implementation, data processing, and application of each technique, along with its capabilities and weaknesses. The book covers many diagnostics employed in the characterization and determination of fuel cell performance. It discusses commonly used conventional tools, such as cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, and transmission electron microscopy. It also examines special tools developed specifically for PEM fuel cells, including transparent cells, cathode discharge, and current mapping, as well as recent advanced tools for diagnosis, such as magnetic resonance imaging and atomic force microscopy. For clarity, the book splits these diagnostic methodologies into two parts—in situ and ex situ. To better understand the tools, PEM fuel cell testing is also discussed. Each self-contained chapter provides cross-references to other chapters. Written by international scientists active in PEM fuel cell research, this volume incorporates state-of-the-art technical advances in PEM fuel cell diagnosis. The diagnostic tools presented help readers to understand the physical and chemical phenomena involved in PEM fuel cells.

Experimental Methods and Mathematical Models to Examine Durability of Polymer Electrolyte Membrane Fuel Cell Catalysts

Experimental Methods and Mathematical Models to Examine Durability of Polymer Electrolyte Membrane Fuel Cell Catalysts PDF Author: Shankar Raman Dhanushkodi
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Proton exchange membrane fuel cells (PEMFC) are attractive energy sources for power trains in vehicles because of their low operating temperature that enables fast start-up and high power densities. Cost reduction and durability are the key issues to be solved before PEMFCs can be successfully commercialized. The major portion of fuel cell cost is associated with the catalyst layer which is typically comprised of carbon-supported Pt and ionomer. The degradation of the catalyst layer is one of the major failure modes that can cause voltage degradation and limit the service life of the fuel cell stack during operation. To develop a highly durable and better performing catalyst layer, topics such as the causes for the degradation, modes of failure, different mechanisms and effect of degradation on fuel cell performance must be studied thoroughly. Key degradation modes of catalyst layer are carbon corrosion and Pt dissolution. These two modes change the electrode structure in the membrane electrode assembly (MEA) and result in catalyst layer thinning, CO2 evolution, Pt deposition in the membrane and Pt agglomeration. Alteration of the electrode morphology can lead to voltage degradation. Accelerated stress tests (ASTs) which simulate the conditions and environments to which fuel cells are subject, but which can be completed in a timely manner, are commonly used to investigate the degradation of the various components. One of the current challenges in employing these ASTs is to relate the performance loss under a given set of conditions to the various life-limiting factors and material changes. In this study, various degradation modes of the cathode catalyst layer are isolated to study their relative impact on performance loss _Fingerprints' of identifiable performance losses due to carbon corrosion are developed for MEAs with 0.4 mg cm−2 cathode platinum loadings. The fingerprint is used to determine the extent of performance loss due to carbon corrosion and Pt dissolution in cases where both mechanisms operate. This method of deconvoluting the contributions to performance loss is validated by comparison to the measured performance losses when the catalyst layer is subjected to an AST in which Pt dissolution is predominant. The limitations of this method iv are discussed in detail. The developed fingerprint suggests that carbon loss leading to CO2 evolution during carbon corrosion ASTs contributes to performance loss of the cell. A mechanistic model for carbon corrosion of the cathode catalyst layer based on one appearing in the literature is developed and validated by comparison of the predicted carbon losses to those measured during various carbon corrosion ASTs. Practical use of the model is verified by comparing the predicted and experimentally observed performance losses. Analysis of the model reveals that the reversible adsorption of water and subsequent oxidation of the carbon site onto which water is adsorbed is the main cause of the current decay during ASTs. Operation of PEM fuel cells at higher cell temperatures and lower relative humidities accelerates Pt dissolution in the catalyst layer during ASTs. In this study, the effects of temperature and relative humidity on MEA degradation are investigated by applying a newly developed AST protocol in which Pt dissolution is predominant and involves the application of a potentiostatic square-wave pulse with a repeating pattern of 3s at 0.6 V followed by 3s at 1.0 V. This protocol is applied at three different temperatures (40°C, 60°C and 80°C) to the same MEA. A diagnostic signature is developed to estimate kinetic losses by making use of the effective platinum surface area (EPSA) obtained from cyclic voltammograms. The analysis indicates that performance degradation occurs mainly due to the loss of Pt in electrical contact with the support and becomes particularly large at 80°C. This Pt dissolution AST protocol is also investigated at three different relative humidities (100%, 50% and 0%). Electrochemical impedance spectroscopy measurements of the MEAs show an increase in both the polarization and ohmic resistances during the course of the AST. Analysis by cyclic voltammetry shows a slight increase in EPSA when the humidity increases from 50% to 100%. The proton resistivity of the ionomer measured by carrying out impedance measurements on MEAs with H2 being fed on the anode side and N2 on the cathode side is found to increase by the time it reaches its end-of-life state when operated under 0 % RH conditions.

Modeling and Diagnostics of Polymer Electrolyte Fuel Cells

Modeling and Diagnostics of Polymer Electrolyte Fuel Cells PDF Author: Ugur Pasaogullari
Publisher: Springer Science & Business Media
ISBN: 0387980687
Category : Science
Languages : en
Pages : 412

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Book Description
This volume, presented by leading experts in the field, covers the latest advances in diagnostics and modeling of polymer electrolyte fuel cells, from understanding catalyst layer durability to start-up under freezing conditions.

Polymer Electrolyte Fuel Cells 17 (PEFC 17)

Polymer Electrolyte Fuel Cells 17 (PEFC 17) PDF Author: D. J. Jones
Publisher: The Electrochemical Society
ISBN: 1607688255
Category : Fuel cells
Languages : en
Pages : 1165

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Book Description


Polymer Electrolyte Fuel Cells 14 (PEFC 14)

Polymer Electrolyte Fuel Cells 14 (PEFC 14) PDF Author: H. Gasteiger
Publisher: The Electrochemical Society
ISBN: 1607685396
Category : Fuel cells
Languages : en
Pages : 1269

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Book Description


Experimental Functional Map of a Polymer Electrolyte Fuel Cell

Experimental Functional Map of a Polymer Electrolyte Fuel Cell PDF Author: Daniel J. L. Brett
Publisher:
ISBN: 9781604565607
Category : Fuel cells
Languages : en
Pages : 0

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Book Description
Fuel cell performance is determined by the complex interplay of mass transport, energy transfer and electrochemical processes. The convolution of these processes leads to spatial heterogeneity in the way that fuel cells perform, particularly due to reactant consumption, water management and the design of fluid-flow plates. It is therefore unlikely that any bulk measurement made on a fuel cell will represent performance at all parts of the cell. The ability to make spatially resolved measurements in a fuel cell provides one of the most useful ways in which to monitor and optimise performance. This book reviews the range of in situ techniques being used to study fuel cells and describes the use of novel experimental techniques that the authors have used to develop an experimental functional map of polymer electrolyte fuel cell (PEFC) performance. These techniques include the mapping of current density, electrochemical impedance, electrolyte conductivity, contact resistance and CO poisoning distribution within working PEFCs, as well as mapping the flow of reactant in gas channels using laser Doppler anemometry (LDA). The combination of these techniques, applied across a range of fuel cell operating conditions allows a unique picture of the internal workings of PEFCs to be obtained and has been used to validate both numerical and analytical models.