Download or read book Tomography based Analysis of Battery Electrolyser and Fuel Cell Microstructures written by Lukas Zielke and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tomography Based Screening of Flow Field written by Lukas Zielke and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Degradation of Li S Battery Electrodes on 3D Current Collectors Studied Using X ray Phase Contrast Tomography written by Lukas Zielke and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Lithium/sulphur batteries are promising candidates for future energy storage systems, mainly due to their high potential capacity. However low sulphur utilization and capacity fading hinder practical realizations. In order to improve understanding of the system, we investigate Li/S electrode morphology changes for different ageing steps, using X-ray phase contrast tomography. Thereby we find a strong decrease of sulphur loading after the first cycle, and a constant loading of about 15% of the initial loading afterwards. While cycling, the mean sulphur particle diameters decrease in a qualitatively similar fashion as the discharge capacity fades. The particles spread, migrate into the current collector and accumulate in the upper part again. Simultaneously sulphur particles lose contact area with the conducting network but regain it after ten cycles because their decreasing size results in higher surface areas. Since the capacity still decreases, this regain could be associated with effects such as surface area passivation and increasing charge transfer resistance

Download or read book Three dimensional Morphology of the Interface Between Micro Porous Layer and Catalyst Layer in a Polymer Electrolyte Membrane Fuel Cell written by Lukas Zielke and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale X ray Computed Tomography Based Modeling of Lithium ion Battery Electrodes written by Ali Ghorbani Kashkooli and published by . This book was released on 2018 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Because of their high energy/power density, long cycle life, and extremely low rate of self-discharge, lithium-ion batteries (LIBs) have dominated portable electronics, smart grid, and electric vehicles (EVs). Although they are the most developed and widely applied energy storage technology, there is still a strong desire to further enhance their energy/power density, cycle life, and safety. While all of these battery requirements are macroscopic and stated at cell/pack scale, they have to be addressed at particle or network of particles scale (mesoscale). At mesoscale, active material particles having different shape and morphologies are bound together with a carbon-doped polymer binder layer. This percolated network of particles serves as the electron conductive path from the reaction sites to the current collector. Even though significant research has been conducted to understand the physical and electrochemical behavior of material at the nanoscale, there have not been comprehensive studies to understand what is happening at the mesoscale. Mathematical models have emerged as a promising way to shed light on complex physical and electrochemical phenomena happening at this scale. The idea of using mathematical model to study multiphysics behavior of LIBs is not new. Traditional models involved homogeneous spherical particles or computer generated electrode structures as the model geometry to simulate electrode/cell performance. While these models are successful to predict the cell performance, heterogeneous electrode's structure at mesoscale questions the accuracy of their findings related to battery internal behavior and property distribution. The new advances in the field of 3D imaging including X-ray computed tomography (XCT) and Focused-ion beam/Scanning electron microscopy (FIB-SEM), have enabled the 3D visualization of the electrode's active particles and structures. In particular, XCT has offered nondestructive imaging and matter penetration capability in short period of time. Although it was commercialized in 70's, with the recent development of high resolution (down to 20 nm) laboratory and synchrotron radiation tomography has been revolutionized. 3D reconstructed electrodes based on XCT data can provide quantitative structural information such as particle and pore size distribution, porosity, solid/electrolyte interfacial surface area, and transport properties. In addition, XCT reconstructed geometry can be easily adopted as the model geometry for simulation purposes. For this, similar to traditional models, a modeling framework based on conservation of mass/charge and electrochemistry needs to be developed. The model links the electrode performance to the real electrode's structure geometry and allows for the detailed investigation of multiphysics phenomena. When combined with mechanical stress, such models can also be used for electrode's failure and degradation studies. The work presented in this dissertation aims to adopt 3D reconstructed structures from nano-XCT as the geometry to study multiphysics behaviour of the LIBs electrodes. In addition, 3D reconstructed structure provides more realistic electrode's morphological and transport properties. Such properties can benefit the homogeneous models by providing highly accurate input parameters. In the first study, a multiscale platform has been developed to model LIB electrodes based on the reconstructed morphology. This multiscale framework consists of a microscale level where the electrode microstructure architecture is modeled and a macroscale level where discharge/charge is simulated. The coupling between two scales is performed in real time unlike using common surrogate based models for microscale. For microscale geometry 3D microstructure is reconstructed based on the nano-XCT data replacing typical computer generated microstructure. It is shown that this model can predict the experimental performance of LiFePO4 (LFP) cathodes at different discharge rates more accurately than the traditional/homogenous models. The approach employed in this study provides valuable insight into the spatial distribution of lithium within the microstructure of LIB electrodes. In the second study, a new model that keeps all major advantages of the single-particle model of LIB and includes three-dimensional structure of the electrode was developed. Unlike the single spherical particle, this model considers a small volume element of an electrode, called the Representative Volume Element (RVE), which represent the real electrode structure. The advantages of using RVE as the model geometry was demonstrated for a typical LIB electrode consisting of nano-particle LFP active material. The model was employed to predict the voltage curve in a half-cell during galvanostatic operations and validated against experimental data. The simulation results showed that the distribution of lithium inside the electrode microstructure is very different from the results obtained based on the single-particle model. In the third study, synchrotron X-ray computed tomography has been utilized using two different imaging modes, absorption and Zernike phase contrast, to reconstruct the real 3D morphology of nanostructured Li4Ti5O12 (LTO) electrodes. The morphology of the high atomic number active material has been obtained using the absorption contrast mode, whereas the percolated solid network composed of active material and carbon-doped polymer binder domain (CBD) has been obtained using the Zernike phase contrast mode. The 3D absorption contrast image revealed that some LTO nano-particles tend to agglomerate and form secondary micro-sized particles with varying degrees of sphericity. The tortuosity of the pore and solid phases were found to have directional dependence, different from Bruggeman's tortuosity commonly used in homogeneous models. The electrode's heterogeneous structure behaviour was also investigated by developing a numerical model to simulate a galvanostatic discharge process using the Zernike phase contrast mode. In the last study, synchrotron X-ray nano-computed tomography has been employed to reconstruct real 3D active particle morphology of a LiMn2O4 (LMO) electrode. For the first time, CBD has been included in the electrode structure as a 108 nm thick uniform layer using image processing technique. With this unique model, stress generated inside four LMO particles with a uniform layer of CBD has been simulated, demonstrating its strong dependence on local morphology (surface concavity and convexity), and the mechanical properties of CBD such as Young's modulus. Specifically, high levels of stress have been found in vicinity of particle's center or near surface concave regions, however much lower than the material failure limits even after discharging rate as high as 5C. On the other hand, the stress inside CBD has reached its mechanical limits when discharged at 5C, suggesting that it can potentially lead to failure by plastic deformation. The findings in this study highlight the importance of modeling LIB active particles with CBD and its appropriate compositional design and development to prevent the loss of electrical connectivity of the active particles from the percolated solid network and power losses due to CBD failure. There are still plenty of opportunities to further develop the methods and models applied in this thesis work to better understand the multiscale multiphysics phenomena happening in the electrode of LIBs. For example, in the multiscale model, microscale solid phase charge transfer and electrolyte mass/charge transfer can be included. In this way, heterogeneous distribution of current density in microscale would be achieved. Also, in both multiscale and RVE models, the exact location of CBD can be incorporated in the electrode structure to specify lithium diffusional path inside the group of particles in the solid matrix. Finally, in the fourth study, the vehicle battery driving cycle can be applied instead of galvanostatic operating condition, to mimic the stress generated inside the electrodes in real practical condition. .

Download or read book Microstructural Characterisation Modelling and Simulation of Solid Oxide Fuel Cell Cathodes written by Jochen Joos and published by . This book was released on 2020-10-09 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work deals with microstructural characterisation, modelling and simulation of SOFC electrodes with the goal of optimizing the electrode microstructures. Methods for a detailed electrode analysis based on focused ion beam (FIB) tomography are presented. A 3D FEM model able to perform simulations of LSCF cathodes based on 3D tomography data is shown. A model generating realistic, yet synthetic microstructures is presented that enables the optimization of microstructural characteristics. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.

Download or read book High Temperature Electrolysis written by Miguel Angel Laguna-Bercero and published by Springer Nature. This book was released on 2023-05-04 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the potential of solid oxide electrolysis cells (SOEC) in the field of hydrogen production. It describes this technology in detail, including fundamentals, state-of-the-art the technology, materials development, current limitations, recent trends and industrial applications. It clarifies SOECs role in decarbonizing the energy sector, drawing on contributions from experts in the field.

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

Download or read book Hydrogen and Fuel Cell written by Johannes Töpler and published by Springer. This book was released on 2015-12-20 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to hydrogen as an essential energy carrier for use with renewable sources of primary energy. It provides an overview of the state of the art, while also highlighting the developmental and market potential of hydrogen in the context of energy technologies; mobile, stationary and portable applications; uninterruptible power supplies and in the chemical industry. Written by experienced practitioners, the book addresses the needs of engineers, chemists and business managers, as well as graduate students and researchers.

Download or read book Micro Energy Harvesting written by Danick Briand and published by John Wiley & Sons. This book was released on 2015-06-22 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: With its inclusion of the fundamentals, systems and applications, this reference provides readers with the basics of micro energy conversion along with expert knowledge on system electronics and real-life microdevices. The authors address different aspects of energy harvesting at the micro scale with a focus on miniaturized and microfabricated devices. Along the way they provide an overview of the field by compiling knowledge on the design, materials development, device realization and aspects of system integration, covering emerging technologies, as well as applications in power management, energy storage, medicine and low-power system electronics. In addition, they survey the energy harvesting principles based on chemical, thermal, mechanical, as well as hybrid and nanotechnology approaches. In unparalleled detail this volume presents the complete picture -- and a peek into the future -- of micro-powered microsystems.

Download or read book Solid Oxide Fuel Cell Lifetime and Reliability written by Nigel Brandon and published by Academic Press. This book was released on 2017-05-23 with total page 235 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid Oxide Fuel Cell Lifetime and Reliability: Critical Challenges in Fuel Cells presents in one volume the most recent research that aims at solving key issues for the deployment of SOFC at a commercial scale and for a wider range of applications. To achieve that, authors from different regions and backgrounds address topics such as electrolytes, contaminants, redox cycling, gas-tight seals, and electrode microstructure. Lifetime issues for particular elements of the fuel cells, like cathodes, interconnects, and fuel processors, are covered as well as new materials. They also examine the balance of SOFC plants, correlations between structure and electrochemical performance, methods for analysis of performance and degradation assessment, and computational and statistical approaches to quantify degradation. For its holistic approach, this book can be used both as an introduction to these issues and a reference resource for all involved in research and application of solid oxide fuel cells, especially those developing understanding in industrial applications of the lifetime issues. This includes researchers in academia and industrial R&D, graduate students and professionals in energy engineering, electrochemistry, and materials sciences for energy applications. It might also be of particular interest to analysts who are looking into integrating SOFCs into energy systems. Brings together in a single volume leading research and expert thinking around the broad topic of SOFC lifetime and durability Explores issues that affect solid oxide fuel cells elements, materials, and systems with a holistic approach Provides a practical reference for overcoming some of the common failure mechanisms of SOFCs Features coverage of integrating SOFCs into energy systems

Download or read book Hydrogen Storage Materials written by R. G. Barnes and published by . This book was released on 1988 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ames Laboratory, Iowa, USA

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.

Download or read book Electrochemical Impedance Spectroscopy in PEM Fuel Cells written by Xiao-Zi (Riny) Yuan and published by Springer Science & Business Media. This book was released on 2009-11-25 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Electrochemical Impedance Spectroscopy in PEM Fuel Cells" discusses one of the most powerful and useful diagnostic tools for various aspects of the study of fuel cells: electrochemical impedance spectroscopy (EIS). This comprehensive reference on EIS fundamentals and applications in fuel cells contains information about basic principles, measurements, and fuel cell applications of the EIS technique. Many illustrated examples are provided to ensure maximum clarity and observability of the spectra. "Electrochemical Impedance Spectroscopy in PEM Fuel Cells" will enable readers to explore the frontiers of EIS technology in PEM fuel cell research and other electrochemical systems. As well as being a useful text for electrochemists, it can also help researchers who are unfamiliar with EIS to learn the technique quickly and to use it correctly in their fuel cell research. Managers or entrepreneurs may also find this book a useful guide to accessing the challenges and opportunities in fuel cell technology.

Download or read book PEM Water Electrolysis written by Dmitri Bessarabov and published by Academic Press. This book was released on 2018-07-23 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen Energy and Fuel Cell Primers is a series of concise books that present those coming into this broad and multidisciplinary field the most recent advances in each of its particular topics. Its volumes bring together information that has thus far been scattered in many different sources under one single title, which makes them a useful reference for industry professionals, researchers and graduate students, especially those starting in a new topic of research. These volumes, PEM Water Electrolysis vol 1 and 2, allows these readers to identify the technology gaps for the development of commercially viable PEM electrolysis systems for energy applications. This primer examines the fundamentals of PEM electrolysis and selected research topics that are currently subject of attention by academic and industry community, such as gas cross-over and AST protocols. This lays the foundation for the exploration of the current industrial trends for PEM electrolysis, such as power to gas application, are discussed, with strong focus on the current trends in the application of PEM electrolysis associated with energy storage. These include durability aspects of PEM electrolysis systems and components, accelerated stress test protocols, manufacturing aspects of large-scale electrolyzers and components, gas crossover problems in PEM electrolyzer safety, and challenges associated with high-current density operation of PEM electrolyzers. A technology development matrix for systems and components requirements will also be covered, as well as unconventional PEM water electrolysis systems, such as ozone generators Presents the fundamentals and most current knowledge in proton exchange membrane water electrolyzers Explores the technology gaps and challenges for commercial deployment of PEM water electrolysis technologies Includes unconventional systems, such as ozone generators Brings together information from many different sources under one single title, making it a useful reference for industry professionals, researchers and graduate students alike

Download or read book Micro computed Tomography micro CT in Medicine and Engineering written by Kaan Orhan and published by Springer. This book was released on 2019-07-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on applications of micro CT, CBCT and CT in medicine and engineering, comprehensively explaining the basic principles of these techniques in detail, and describing their increasing use in the imaging field. It particularly highlights the scanning procedure, which represents the most crucial step in micro CT, and discusses in detail the reconstruction process and the artifacts related to the scanning processes, as well as the imaging software used in analysis. Written by international experts, the book illustrates the application of micro CT in different areas, such as dentistry, medicine, tissue engineering, aerospace engineering, geology, material engineering, civil engineering and additive manufacturing. Covering different areas of application, the book is of interest not only to specialists in the respective fields, but also to broader audience of professionals working in the fields of imaging and analysis, as well as to students of the different disciplines.

Download or read book Materials for Advanced Batteries written by D. Murphy and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of a NATO Science Committee Institute on "Materials for Advanced Batteries" was suggested to JB and DWM by Dr. A. G. Chynoweth. His idea was to bring together experts in the field over the entire spectrum of pure research to applied research in order to familiarize everyone with potentially interesting new systems and the problems involved in their development. Dr. M. C. B. Hotz and Professor M. N. Ozdas were instrumental in helping organize this meeting as a NATO Advanced Science Institute. An organlzlng committee consisting of the three of us along with W. A. Adams, U. v Alpen, J. Casey and J. Rouxel organized the program. The program consisted of plenary talks and poster papers which are included in this volume. Nearly half the time of the conference was spent in study groups. The aim of these groups was to assess the status of several key aspects of batteries and prospects for research opportunities in each. The study groups and their chairmen were: Current status and new systems J. Broadhead High temperature systems W. A. Adams Interface problems B. C. H. Steele Electrolytes U. v Alpen Electrode materials J. Rouxel These discussions are summarized in this volume. We and all the conference participants are most grateful to Professor J. Rouxel for suggesting the Aussois conference site, and to both he and Dr. M. Armand for handling local arrangements.