Download or read book Grain size Effects in Nanoscaled Electrolyte and Cathode Thin Films for Solid Oxide Fuel Cells SOFC written by Christoph Peters and published by KIT Scientific Publishing. This book was released on 2009 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their high energy conversion efficiencies and low emissions, Solid Oxide Fuel Cells (SOFCs) show promise as a replacement for combustion-based electrical generators at all sizes. Further increase of SOFC efficiency can be achieved by microstructural optimization of the oxygen-ion conducting electrolyte and the mixed ionic-electronic conducting cathode. By application of nanoscaled thin films, the exceptionally high efficiency allows the realization of mobile SOFCs.

Download or read book Microstructural Characterisation Modelling and Simulation of Solid Oxide Fuel Cell Cathodes written by Joos, Jochen and published by KIT Scientific Publishing. This book was released on 2017-06-29 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrogen Technology written by Moisés Romolos Cesario and published by Elsevier. This book was released on 2024-06-28 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen Technology: Fundamentals and Applications relates theoretical concepts to practical case studies in the field of hydrogen technology with an emphasis on materials and their applications. To implement hydrogen conversion production processes, it is crucial to understand the structural, microstructural, textural, thermal, catalytic, and electrochemical properties of materials. Covering nanomaterials, heterogeneous catalysis, greenhouse gas conversion, reforming reactions for hydrogen production, valorization of hydrogen energy, biomass valorization, the hydrogen economy, and its technical feasibility, this book addresses how bio/hydrogen technology can be used to solve environmental problems, including how to produce, convert, and store energy through electro/catalytic reactions and chemical valorization. Providing an understanding of the different factors involved, such as the availability of raw material, location, viable process and production scale, and economic criteria, this book will especially be of interest to engineers, scientists, and students in the field of hydrogen technology. Explains the phenomena that govern electrocatalytic/catalytic reactions Covers the study of new materials design and industrial processes Includes process improvements for obtaining hydrogen via chemical and biological processes

Download or read book Characterization and Modeling of Electrochemical Energy Conversion Systems by Impedance Techniques written by Dino Klotz and published by KIT Scientific Publishing. This book was released on 2014-07-30 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis introduces (i) amendments to basic electrochemical measurement techniques in the time and frequency domain suitable for electrochemical energy conversion systems like fuel cells and batteries, which enable shorter measurement times and improved precision in both measurement and parameter identification, and (ii) a modeling approach that is able to simulate a technically relevant system just by information gained through static and impedance measurements of laboratory size cells.

Download or read book Finite Element Method FEM Model and Performance Analysis of Solid Oxide Fuel Cells written by Geisler, Helge Ingolf and published by KIT Scientific Publishing. This book was released on 2019-07-10 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a numerical FEM framework, capable of predicting SOFC performance under technically relevant, planar stack contacting conditions. A high level of confidence in the model predictions is supplied by using exclusively experimentally determined material/kinetic parameters and by a comprehensive validation. The presented model aids SOFC stack development by pre-evaluating possible material choices and design combinations for cells/interconnectors without any experimental effort.

Download or read book SOFC Modelling and Parameter Identification by Means of Impedance Spectroscopy written by André Leonide and published by KIT Scientific Publishing. This book was released on 2010 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: A high resolution electrochemical impedance spectroscopy study on anode supported single cells (ASC) is presented. The cells were characterised over a broad range of operating conditions, including different temperatures, current densities and various cathode and anode gas compositions.The analysis of the distribution of relaxation times combined with the numeric accuracy of a CNLS fit enabled the identification of five different processes contributing to the total polarisation loss of an ASC.

Download or read book Model based Interpretation of the Performance and Degradation of Reformate Fueled Solid Oxide Fuel Cells written by Alexander Kromp and published by KIT Scientific Publishing. This book was released on 2014-05-12 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid oxide fuel cells offer great prospects for the sustainable, clean and safe conversion of various fuels into electrical energy. In this thesis, the performance-determining loss processes for the cell operation on reformate fuels are elucidated via electrochemical impedance spectroscopy. Model-based analyses reveal the electrochemical fuel oxidation mechanism, the coupling of fuel gas transport and reforming chemistry and the impact of fuel impurities on the degradation of each loss process.

Download or read book Physically based Impedance Modelling of Lithium Ion Cells written by Illig, Joerg and published by KIT Scientific Publishing. This book was released on 2014-09-19 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, a new procedure to analyze lithium-ion cells is introduced. The cells are disassembled to analyze their components in experimental cell housings. Then, Electrochemical Impedance Spectroscopy, time domain measurements and the Distribution function of Relaxation Times are applied to obtain a deep understanding of the relevant loss processes. This procedure yields a notable surplus of information about the electrode contributions to the overall internal resistance of the cell.

Download or read book Electrochemical Performance and Stability of Ba Sr Co Fe O for Oxygen Transport Membranes written by Niedrig, Christian and published by KIT Scientific Publishing. This book was released on 2015-12-23 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed ionic-electronic conducting (MIEC) ceramics as oxygen transport membranes (OTMs) can provide high oxygen permeation rates at comparably low energy demands. For this purpose, Ba?.?Sr?.?Co?.?Fe?.?O??? (BSCF) shows the best performance under ideal operating conditions. Thermal and chemical stability investigations, electrical behavior ?(T,pO?,t), and oxygen exchange parameter extraction by means of electrical conductivity relaxation resulted in a far better understanding of the BSCF system.

Download or read book Micro Nano Engineering of Fuel Cells written by Dennis Y.C. Leung and published by CRC Press. This book was released on 2015-04-24 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fuel cells are clean and efficient energy conversion devices expected to be the next generation power source. During more than 17 decades of research and development, various types of fuel cells have been developed with a view to meet the different energy demands and application requirements. Scientists have devoted a great deal of time and effort

Download or read book The Electrochemical Oxidation of H2 and CO at Patterned Ni Anodes of SOFCs written by Annika Utz and published by KIT Scientific Publishing. This book was released on 2014-08-22 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, a deeper understanding of the electrochemical oxidation at SOFC anodes was gained by the experimental characterization of patterned Ni anodes in H2-H2O and CO-CO2 atmosphere. By high resolution data analysis, the Line Specific Resistance attributed to charge transfer and its dependencies on gas composition, temperature and polarization voltage were identified. Furthermore, the comparison of the performance of patterned and cermet anodes was enabled using a transmission line model.

Download or read book Nanoscale Surface Engineering for Ceramic Fuel Cells written by Young Beom Kim and published by Stanford University. This book was released on 2011 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ceramic fuel cell (CFC) is an all-solid-state energy conversion device and usually refers to fuel cells employing solid ceramic electrolytes. The present generation of ceramic fuel cells can be classified into two types according to the electrolytes they use: oxygen ion conducting fuel cells, or solid oxide fuel cells (SOFCs) and proton conducting fuel cells (PCFC or PCOFC). CFCs usually have the highest operating temperature of all fuel cells at about 600~1000oC for reasonably active charge transfer reactions at the electrode-electrolyte interface and ion transport through the electrolyte. This high CFC's operating temperature has limited practical applications. The goal of my Ph.D. research is to minimize the activation losses at the electrode/electrolyte interface by nanoscale engineering to achieve decent performance of ceramic fuel cells at lower operating temperatures (300~500oC). This dissertation has three main nanoscale surface engineering approaches according to the fuel cell components: electrode structure, composite electrolyte structures with thin interlayers, and the fabrication of three-dimensional fuel cell membrane-electrode assemblies (MEAs). We would call the first part of the dissertation as nanoscale electrode structure engineering for ceramic fuel cells. It describes the fabrication and investigation of morphologically stable model electrode structures with well-defined and sharp platinum/yttria stabilized zirconia (YSZ) interfaces to study geometric effects at triple phase boundaries (TPB), which is known as the actual electrochemical reaction site. A nanosphere lithography (NSL) technique using monodispersed silica nanoparticles is employed to deposit nonporous platinum electrodes containing close-packed arrays of circular openings through the underlying YSZ surface. These nano-structured dense Pt array cathodes exhibited better structural integrity and thermal stability at the fuel cell operating temperature of 450~500oC when compared to porous sputtered Pt electrodes. More importantly, electrochemical studies on geometrically well-defined Pt/YSZ sharp interfaces demonstrated that the cathode impedance and cell performance both scale almost linearly with aerial density of TPB length. These controlled experiments also allowed for the estimation of the area of the electrochemical reaction zone. This information can be used as a platform for designing the electrode structure to maximize the performance of ceramic fuel cells. The second part of the experiment is about electrolyte surface structure engineering by fabricating composite electrolyte structures. This study describes, both theoretically and experimentally, the role of doped ceria cathodic interlayers and their surface grain boundaries in enhancing oxygen incorporation kinetics. Quantum mechanical simulations of oxygen incorporation energetics support the experimental results and indicate a low activation energy of only 0.07eV for yttria-doped ceria (YDC), while the incorporation reaction on YSZ is activated by a significantly higher energy barrier of 0.38eV. For experiments, epitaxial and polycrystalline YDC, gadolinia-doped ceria (GDC) thin films were grown by pulsed laser deposition (PLD) on the cathode side of 300[Mu]m-thick single crystalline (100) and 100[Mu]m-thick polycrystalline YSZ substrates, respectively. For the composite electrolyte sample with YDC interlayer, the Oxygen isotope exchange experiment was conducted employing secondary ion mass spectrometry (SIMS) with high spatial resolution (50nm). The surface mapping result of 18O/16O shows high activity at surface grain boundary regions indicating that the grain boundary regions are electrochemically active for oxygen incorporation reaction. Fuel cell current-voltage behavior and electrochemical impedance spectroscopy measurements were carried out in the temperature range of 350oC-450oC on both single crystalline and polycrystalline interlayered cells. Results of dc and ac measurements confirm that cathodic resistances of cells with epitaxial doped-cerium oxides (GDC, YDC) layers are lower than that for the YSZ-only control cell. This is attributed to the higher surface exchange coefficient for doped-cerium oxides than for YSZ. Moreover, the role of grain boundary density at the cathode side external surface was investigated on surface-engineered electrode-membrane assemblies (MEA) having different doped-ceria surface grain sizes. MEAs having smaller surface grain size show better cell performance and correspondingly lower electrode interfacial resistance. Electrochemical measurements suggest that doped-ceria grain boundaries at the cathode side contribute to the enhancement of oxygen surface kinetics. These results provide an opportunity and a microstructure design pathway to improve performance of LT-SOFCs by surface engineering with nano-granular, catalytically superior thin doped-ceria cathodic interlayers. Thirdly, as a reaction surface engineering for SOFC, we investigated a novel method for creating a three-dimensional (3-D) fuel cell architecture to enhance fuel cell performance by increasing the area of the electrolyte membrane. The research describes the fabrication and operation of a low temperature 3-D protonically conducting ceramic fuel cell featuring a close packed and free standing crater patterned architecture achieved by nanospherical patterning (NSP) and dry etching techniques. The cell employed conformal layers of yttria-doped barium zirconate (BYZ) anhydrous electrolyte membrane (~120nm) sandwiched between thin (~70nm) sputtered porous Pt electrode layers. The fuel cell structure achieved the highest reported peak power densities up to 186 mW/cm2 at 450oC using hydrogen as fuel. To further investigate the proton conductivity of the electrolyte, which is BYZ, we studied the effect of crystalline structures on proton conductivity of BYZ thin films. The results showed that the grain boundaries impede the proton transport through the grain boundary and cause extremely high resistance for ionic transport in the film. This experimental result also can provide significant implications in designing proton conducting ceramic fuel cells. All these efforts and investigations were intended to enhance the ceramic fuel cell performance at low operating temperatures (300--500oC) by improving electrode/electrolyte interface electrochemical reactions. We expect to achieve further enhancement when we combine the approaches each other. For example, fabrication of three-dimensional fuel cells with doped-ceria interlayers and composite electrolyte structures with optimized electrode nano-structures. Investigations are on-going in our laboratory as a future work.

Download or read book Metal Oxide Based Thin Film Structures written by Nini Pryds and published by Elsevier. This book was released on 2017-09-07 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal Oxide-Based Thin Film Structures: Formation, Characterization and Application of Interface-Based Phenomena bridges the gap between thin film deposition and device development by exploring the synthesis, properties and applications of thin film interfaces. Part I deals with theoretical and experimental aspects of epitaxial growth, the structure and morphology of oxide-metal interfaces deposited with different deposition techniques and new developments in growth methods. Part II concerns analysis techniques for the electrical, optical, magnetic and structural properties of thin film interfaces. In Part III, the emphasis is on ionic and electronic transport at the interfaces of Metal-oxide thin films. Part IV discusses methods for tailoring metal oxide thin film interfaces for specific applications, including microelectronics, communication, optical electronics, catalysis, and energy generation and conservation. This book is an essential resource for anyone seeking to further their knowledge of metal oxide thin films and interfaces, including scientists and engineers working on electronic devices and energy systems and those engaged in research into electronic materials. Introduces the theoretical and experimental aspects of epitaxial growth for the benefit of readers new to the field Explores state-of-the-art analysis techniques and their application to interface properties in order to give a fuller understanding of the relationship between macroscopic properties and atomic-scale manipulation Discusses techniques for tailoring thin film interfaces for specific applications, including information, electronics and energy technologies, making this book essential reading for materials scientists and engineers alike

Download or read book Smart Composite Coatings and Membranes written by Maria Fatima Montemor and published by Elsevier. This book was released on 2015-11-09 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Smart Composite Coatings and Membranes: Transport, Structural, Environmental and Energy Applications provides the latest information on the increase in demand for new smart materials for a wide array of different technological applications. The book comprehensively reviews the latest developments in smart composite materials used as membranes, barriers, and coatings, with a special focus on corrosion protection, transportation, structure, and the wide range of applications. Part one examines the properties, processing, and manufacture of smart composite materials, along with techniques for modeling the behavior of these materials, while other sections review the use of smart composite coatings in aerospace, marine, and metal structural applications, examine the protective properties and applications of smart composite coatings, and introduce specific low environmental impact and energy efficient applications, such as energy generation and storage, water management, and stone conservation. Explores the use of smart composite materials for coatings, barriers and membranes Comprehensively reviews the latest developments in smart composite materials, with a special focus on corrosion protection, transportation, structure, and the wide range of applications Examines the properties, processing, manufacture and behavior modeling of smart composite materials Focuses on applications that have an impact on more effective energy savings and efficiency, green-house emissions, and environmental protection

Download or read book High temperature Solid Oxide Fuel Cells Fundamentals Design and Applications written by S.C. Singhal and published by Elsevier. This book was released on 2003-12-08 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: High Temperature Solid Oxide Fuel Cells: Fundamentals, Design and Applications provides a comprehensive discussion of solid oxide fuel cells (SOFCs). SOFCs are the most efficient devices for the electrochemical conversion of chemical energy of hydrocarbon fuels into electricity, and have been gaining increasing attention for clean and efficient distributed power generation. The book explains the operating principle, cell component materials, cell and stack designs and fabrication processes, cell and stack performance, and applications of SOFCs. Individual chapters are written by internationally renowned authors in their respective fields, and the text is supplemented by a large number of references for further information. The book is primarily intended for use by researchers, engineers, and other technical people working in the field of SOFCs. Even though the technology is advancing at a very rapid pace, the information contained in most of the chapters is fundamental enough for the book to be useful even as a text for SOFC technology at the graduate level.

Download or read book Nanotechnology for Energy Sustainability written by Baldev Raj and published by John Wiley & Sons. This book was released on 2017-01-27 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt: In three handy volumes, this ready reference provides a detailed overview of nanotechnology as it is applied to energy sustainability. Clearly structured, following an introduction, the first part of the book is dedicated to energy production, renewable energy, energy storage, energy distribution, and energy conversion and harvesting. The second part then goes on to discuss nano-enabled materials, energy conservation and management, technological and intellectual property-related issues and markets and environmental remediation. The text concludes with a look at and recommendations for future technology advances. An essential handbook for all experts in the field - from academic researchers and engineers to developers in industry.

Download or read book High Temperature Solid Oxide Fuel Cells for the 21st Century written by Kevin Kendall and published by Elsevier. This book was released on 2015-11-21 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: High-temperature Solid Oxide Fuel Cells, Second Edition, explores the growing interest in fuel cells as a sustainable source of energy. The text brings the topic of green energy front and center, illustrating the need for new books that provide comprehensive and practical information on specific types of fuel cells and their applications. This landmark volume on solid oxide fuel cells contains contributions from experts of international repute, and provides a single source of the latest knowledge on this topic. A single source for all the latest information on solid oxide fuel cells and their applications Illustrates the need for new, more comprehensive books and study on the topic Explores the growing interest in fuel cells as viable, sustainable sources of energy