Download or read book Structure and Energetics of Nanoparticles and Ionomer Films in Fuel Cell Catalyst Layers written by Qianping He and published by . This book was released on 2013 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Improving the durability and utilization efficiency of the platinum-on-carbon (Pt/C) catalyst is of vital importance to the commercialization of the polymer electrolyte membrane fuel cell (PEMFC). This body of work provides molecular level insights to aid the fulfillment of this goal. Chapter 1 describes the use of molecular dynamics (MD) simulation in an effort to understand the Pt/C degradation issue from the nano-adhesion point of view. The roles of catalyst nanoparticle size, shape, Pt/C surface oxidation and the extent of ionomer film hydration are investigated to study their effects on nano-particle adhesion. It is found that the adhesion force strengthens as the Pt size goes up. Nanoparticle of tetrahedral shape exhibits relatively stronger connection with the carbon. The hydroxylated surface enhances nano-adhesion and epoxidized surface diminishes the adhesion. The presence of ionomer film strengthens the adhesion. Chapter 2 uses MD simulations to investigate the microstructure of the catalyst layer, which is essential information needed for increasing the catalyst utilization rate. The ionomer film thickness, hydration level, surface oxidation of Pt/C, presence of Pt or PtO catalysts are key variables studied for their effects on the catalyst layer microstructure and transport properties. It is concluded that the oxidation of the carbon surface and the presence of Pt or PtO catalyst drastically influence the ionomer film configuration and the water distribution on the surface. The thickness of the ionomer film is directly related with its ability of retaining water. Chapter 3 describes experimental work exploring the effect of radiation damage on the microscopic characterization of the catalyst layer of the PEMFCs. It also provides information on the feasibility of in-situ nano-adhesion measurements inside the SEM. It is found that the radiation damage of the catalyst sample usually starts from the interface of Pt/C and primarily occurs in the form of mass loss accompanied by atomic displacement and edge curl. The results indicate the low reliability of the in-situ nano-adhesion measurement. All three chapters serve to expand the fundamental understanding of the microstructure of the catalyst layer, which contribute to the development of a more durable, less expensive and better performing PEMFC.

Download or read book Control of Ionomer Distribution and Porosity in Roll to Roll Coated Fuel Cell Catalyst Layers written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As fuel cells transition from the laboratory to industrial production for vehicles and other applications there is a need to understand how manufacturing processes impact the properties and, ultimately, the performance of materials. Roll-to-roll coating enables processing at meters per second speeds with physics that can be quite different from common laboratory coating methods. In this work, we have focused on the coating of catalyst layers for proton exchange membrane fuel cells. Commonly, laboratory samples are prepared using spray coating or hand painting, which effectively coat many thin layers to achieve the desired catalyst layer thickness. This creates catalyst layers with uniform distributions of materials throughout the thickness of the full catalyst layer. In contrast, roll-to-roll methods, like slot die and gravure, coat the catalyst layer as a single wet film. As the film dries, ink constituents are able to segregate, leading to a heterogeneous distribution of materials through the thickness of the layer. It is also known that solvent and drying rate can affect the morphology of the catalyst layer. Thus, there is a need to understand how ink formulation and the drying process influence the distribution of materials and catalyst layer morphology. Here, we have explored the influence of solvent and drying rate on morphology of roll-to-roll coated catalyst layers. We show the development of the Kelvin probe method as a rapid screening technique for qualitative analysis of ionomer distribution. We also utilize nano X-ray computed tomography to visualize electrode structure and to quantify particle-size and pore-size distributions, thickness-dependent ionomer distribution, tortuosity, and effective transport properties. We find that solvent has a strong influence on ionomer distribution, with less of an effect on porosity. Conversely, drying temperature has a strong influence on porosity, but less influence on ionomer distribution. Finally, we utilize in situ fuel cell performance testing and other advanced diagnostics to quantify the impact of catalyst layer properties on fuel cell performance and demonstrate that roll-to-roll coating is capable of coating high performance catalyst layers in multi-meter lengths. have focused on the coating of catalyst layers for proton exchange membrane fuel cells. Commonly, laboratory samples are prepared using spray coating or hand painting, which effectively coat many thin layers to achieve the desired catalyst layer thickness. This creates catalyst layers with uniform distributions of materials throughout the thickness of the full catalyst layer. In contrast, roll-to-roll methods, like slot die and gravure, coat the catalyst layer as a single wet film. As the film dries, ink constituents are able to segregate, leading to a heterogeneous distribution of materials through the thickness of the layer. It is also known that solvent and drying rate can affect the morphology of the catalyst layer. Thus, there is a need to understand how ink formulation and the drying process influence the distribution of materials and catalyst layer morphology. Here, we have explored the influence of solvent and drying rate on morphology of roll-to-roll coated catalyst layers. We show the development of the Kelvin probe method as a rapid screening technique for qualitative analysis of ionomer distribution. We also utilize nano X-ray computed tomography to visualize electrode structure and to quantify particle-size and pore-size distributions, thickness-dependent ionomer distribution, tortuosity, and effective transport properties. We find that solvent has a strong influence on ionomer distribution, with less of an effect on porosity. Conversely, drying temperature has a strong influence on porosity, but less influence on ionomer distribution. Finally, we utilize in situ fuel cell performance testing and other advanced diagnostics to quantify the impact of catalyst layer properties on fuel cell performance and demonstrate that roll-to-roll coating is capable of coating high performance catalyst layers in multi-meter lengths.

Download or read book Fuel Cell Science written by Andrzej Wieckowski and published by John Wiley & Sons. This book was released on 2010-10-12 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive survey of theoretical andexperimental concepts in fuel cell chemistry Fuel cell science is undergoing significant development, thanks, in part, to a spectacular evolution of the electrocatalysis concepts, and both new theoretical and experimental methods. Responding to the need for a definitive guide to the field, Fuel Cell Science provides an up-to-date, comprehensive compendium of both theoretical and experimental aspects of the field. Designed to inspire scientists to think about the future of fuel cell technology, Fuel Cell Science addresses the emerging field of bio-electrocatalysis and the theory of heterogeneous reactions in fuel cell science and proposes potential applications for electrochemical energy production. The book is thorough in its coverage of the electron transfer process and structure of the electric double layer, as well as the development of operando measurements. Among other subjects, chapters describe: Recently developed strategies for the design, preparation, and characterization of catalytic materials for fuel cell electrodes, especially for new fuel cell cathodes A wide spectrum of theoretical and computational methods, with?the aim of?developing?new fuel cell catalysis concepts and improving existing designs to increase their performance.? Edited by two leading faculty, the book: Addresses the emerging fields of bio-electrocatalysis for fuel cells and theory of heterogeneous reactions for use in fuel cell catalysis Provides a survey of experimental and theoretical concepts in these new fields Shows the evolution of electrocatalysis concepts Describes the chemical physics of fuel cell reactions Forecasts future developments in electrochemical energy production and conversion Written for electrochemists and electrochemistry graduate students, electrocatalysis researchers, surface and physical chemists, chemical engineers, automotive engineers, and fuel cell and energy-related researchers, this modern compendium can help today's best minds meet the challenges in fuel science technology.

Download or read book Control of Ionomer Distribution in Roll to Roll Coated Fuel Cell Catalyst Layers written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel cell catalyst layers are a complex mixture of catalyst particles and ion-conducting polymers. The performance of catalyst layers is highly dependent on microstructure, which must balance proton and electron conduction with gas transport. As fuel cells transition from the laboratory to industrial production for vehicles and other applications, there is a need to understand how manufacturing processes impact the microstructure and, ultimately, the performance of catalyst layers. In this work, we have focused on the roll-to-roll coating of catalyst layers for proton exchange membrane fuel cells. The catalyst layers are responsible for the electrochemical reactions that enable power production. In these devices the catalyst is commonly a Pt nanoparticle supported on porous carbon blacks. The ion conducting polymer, or ionomer, is typically a perfluorosulfonic acid. The most common being Nafion. To fabricate the catalyst layer, the catalyst particles are dispersed in an ink with the ionomer and cast to form the catalyst layer. Commonly, laboratory samples are prepared using spray coating or hand painting, which effectively coat many thin layers to achieve the desired catalyst layer thickness. This creates catalyst layers with uniform distributions of materials throughout the thickness of the full catalyst layer. In contrast, roll-to-roll methods, like slot die, gravure or screen printing, coat the catalyst layer as a single wet film. As the film dries, ink constituents are able to segregate, leading to a heterogeneous distribution of materials through the thickness of the layer. It is also known that the choice of solvent and drying rate can affect the morphology of the catalyst layer. Thus, there is a need to understand how ink formulation and the drying process influence the distribution of materials and catalyst layer morphology. Here, we have explored the influence of solvent and drying rate on morphology of roll-to-roll coated catalyst layers. We show the development of the Kelvin probe method as a rapid screening technique for qualitative analysis of ionomer distribution. We also utilize nano X-ray computed tomography to visualize electrode structure and to quantify particle-size and pore-size distributions, thickness-dependent ionomer distribution, tortuosity, and effective transport properties. We find that solvent has a strong influence on ionomer distribution, with less of an effect on porosity. Conversely, drying temperature has a strong influence on porosity, but less influence on ionomer distribution. Finally, we utilize in situ fuel cell performance testing and other advanced diagnostics to quantify the impact of catalyst layer properties on fuel cell performance and demonstrate that roll-to-roll coating is capable of coating high performance catalyst layers in multi-meter lengths.

Download or read book Polymer Electrolyte Fuel Cells 10 written by Hubert Andreas Gasteiger and published by The Electrochemical Society. This book was released on 2010-10 with total page 2081 pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue of ECS Transactions reports on research, development, and engineering of polymer electrolyte fuel cells (PEFCs), as well as low-temperature direct-fuel cells using either anion or cation exchange membranes. It discusses diagnostic techniques and systems design for both acid and alkaline fuel cells, catalysts and membranes for acid fuel cells, and catalysts and membranes for alkaline fuel cells.

Download or read book PEM Fuel Cell Electrocatalysts and Catalyst Layers written by Jiujun Zhang and published by Springer Science & Business Media. This book was released on 2008-08-26 with total page 1147 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book One dimensional Nanostructures for PEM Fuel Cell Applications written by Shangfeng Du and published by Academic Press. This book was released on 2017-08-07 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: One-dimensional Nanostructures for PEM Fuel Cell Applications provides a review of the progress made in 1D catalysts for applications in polymer electrolyte fuel cells. It highlights the improved understanding of catalytic mechanisms on 1D nanostructures and the new approaches developed for practical applications, also including a critical perspective on current research limits. The book serves as a reference for the design and development of a new generation of catalysts to assist in the realization of successful commercial use that have the potential to decarbonize the domestic heat and transport sectors. In addition, a further commercialization of this technology requires advanced catalysts to address major obstacles faced by the commonly used Pt/C nanoparticles. The unique structure of one-dimensional nanostructures give them advantages to overcome some drawbacks of Pt/C nanoparticles as a new type of excellent catalysts for fuel cell reactions. In recent years, great efforts have been devoted in this area, and much progress has been achieved. Provides a review of 1D catalysts for applications in polymer electrolyte fuel cells Presents an ideal reference for the design and development of a new generation of catalysts to assist in the realization of successful commercial use Highlights the progress made in recent years in this emerging field

Download or read book Polymer Electrolyte Fuel Cells written by Michael Eikerling and published by CRC Press. This book was released on 2014-09-23 with total page 567 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book provides a systematic and profound account of scientific challenges in fuel cell research. The introductory chapters bring readers up to date on the urgency and implications of the global energy challenge, the prospects of electrochemical energy conversion technologies, and the thermodynamic and electrochemical principles underlying the op

Download or read book Nanomaterials for Fuel Cell Catalysis written by Kenneth I. Ozoemena and published by Springer. This book was released on 2016-07-05 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global experts provide an authoritative source of information on the use of electrochemical fuel cells, and in particular discuss the use of nanomaterials to enhance the performance of existing energy systems. The book covers the state of the art in the design, preparation, and engineering of nanoscale functional materials as effective catalysts for fuel cell chemistry, highlights recent progress in electrocatalysis at both fuel cell anode and cathode, and details perspectives and challenges in future research.

Download or read book Nanostructured and Advanced Materials for Fuel Cells written by San Ping Jiang and published by CRC Press. This book was released on 2013-12-07 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boasting chapters written by leading international experts, Nanostructured and Advanced Materials for Fuel Cells provides an overview of the progress that has been made so far in the material and catalyst development for fuel cells. The book covers the most recent developments detailing all aspects of synthesis, characterization, and performance.It

Download or read book Polymer Electrolyte Fuel Cells and Electrolyzers 18 PEFC E 18 written by D. J. Jones and published by The Electrochemical Society. This book was released on 2018-09-21 with total page 745 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanomaterials for Alcohol Fuel Cells written by Inamuddin and published by Materials Research Forum LLC. This book was released on 2019-05-25 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alcohol fuel cells are very attractive as power sources for mobile and portable applications. As they convert the chemical energy of fuels into electricity, much recent research is directed at developing suitable and efficient catalysts for the process. The present book focuses on pertinent types of nanomaterial-based catalysts, membranes and supports.

Download or read book Comprehensive Nanoscience and Nanotechnology written by and published by Academic Press. This book was released on 2019-01-02 with total page 1881 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Nanoscience and Technology, Second Edition, Five Volume Set allows researchers to navigate a very diverse, interdisciplinary and rapidly-changing field with up-to-date, comprehensive and authoritative coverage of every aspect of modern nanoscience and nanotechnology. Presents new chapters on the latest developments in the field Covers topics not discussed to this degree of detail in other works, such as biological devices and applications of nanotechnology Compiled and written by top international authorities in the field

Download or read book Fuel Cells and Hydrogen Production written by Timothy E. Lipman and published by Springer. This book was released on 2018-10-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The expected end of the “oil age” will lead to increasing focus and reliance on alternative energy conversion devices, among which fuel cells have the potential to play an important role. Not only can phosphoric acid and solid oxide fuel cells already efficiently convert today’s fossil fuels, including methane, into electricity, but other types of fuel cells, such as polymer electrolyte membrane fuel cells, have the potential to become the cornerstones of a possible future hydrogen economy. This handbook offers concise yet comprehensive coverage of the current state of fuel cell research and identifies key areas for future investigation. Internationally renowned specialists provide authoritative introductions to a wide variety of fuel cell types and hydrogen production technologies, and discuss materials and components for these systems. Sustainability and marketing considerations are also covered, including comparisons of fuel cells with alternative technologies.

Download or read book Advanced Electrochemical Materials in Energy Conversion and Storage written by Junbo Hou and published by CRC Press. This book was released on 2022-03-30 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on novel electrochemical materials particularly designed for specific energy applications. It presents the relationship between materials properties, state-of-the-art processing, and device performance and sheds light on the research, development, and deployment (RD&D) trend of emerging materials and technologies in this field. Features: Emphasizes electrochemical materials applied in PEM fuel cells and water splitting Summarizes anode, cathode, electrolyte, and additive materials developed for lithium-ion batteries and reviews other batteries, including lithium-air, lithium-sulfur, sodium- and potassium-ion batteries, and multivalent-ion batteries Discusses advanced carbon materials for supercapacitors Highlights catalyst design and development for CO2RR and fundamentals of proton facilitated reduction reactions With a cross-disciplinary approach, this work will be of interest to scientists and engineers across chemical engineering, mechanical engineering, materials science, chemistry, physics, and other disciplines working to advance electrochemical energy conversion and storage capabilities and applications.

Download or read book Polymer Electrolyte Fuel Cells 17 PEFC 17 written by D. J. Jones and published by The Electrochemical Society. This book was released on 2017 with total page 1165 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Electrolyte Fuel Cell Durability written by Felix N. Büchi and published by Springer Science & Business Media. This book was released on 2009-02-08 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers a significant number of R&D projects, performed mostly after 2000, devoted to the understanding and prevention of performance degradation processes in polymer electrolyte fuel cells (PEFCs). The extent and severity of performance degradation processes in PEFCs were recognized rather gradually. Indeed, the recognition overlapped with a significant number of industrial dem- strations of fuel cell powered vehicles, which would suggest a degree of technology maturity beyond the resaolution of fundamental failure mechanisms. An intriguing question, therefore, is why has there been this apparent delay in addressing fun- mental performance stability requirements. The apparent answer is that testing of the power system under fully realistic operation conditions was one prerequisite for revealing the nature and extent of some key modes of PEFC stack failure. Such modes of failure were not exposed to a similar degree, or not at all, in earlier tests of PEFC stacks which were not performed under fully relevant conditions, parti- larly such tests which did not include multiple on–off and/or high power–low power cycles typical for transportation and mobile power applications of PEFCs. Long-term testing of PEFCs reported in the early 1990s by both Los Alamos National Laboratory and Ballard Power was performed under conditions of c- stant cell voltage, typically near the maximum power point of the PEFC.