Characterization and Modeling of Electrochemical Energy Conversion Systems by Impedance Techniques

Characterization and Modeling of Electrochemical Energy Conversion Systems by Impedance Techniques

Author: Dino Klotz

Publisher: KIT Scientific Publishing

Published: 2014-07-30

Total Pages: 182

ISBN-13: 3866449038

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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.


Microstructural Characterisation, Modelling and Simulation of Solid Oxide Fuel Cell Cathodes

Microstructural Characterisation, Modelling and Simulation of Solid Oxide Fuel Cell Cathodes

Author: Joos, Jochen

Publisher: KIT Scientific Publishing

Published: 2017-06-29

Total Pages: 246

ISBN-13: 3731506254

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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.


Model-based Interpretation of the Performance and Degradation of Reformate Fueled Solid Oxide Fuel Cells

Model-based Interpretation of the Performance and Degradation of Reformate Fueled Solid Oxide Fuel Cells

Author: Alexander Kromp

Publisher: KIT Scientific Publishing

Published: 2014-05-12

Total Pages: 146

ISBN-13: 373150006X

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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.


Physically based Impedance Modelling of Lithium-Ion Cells

Physically based Impedance Modelling of Lithium-Ion Cells

Author: Illig, Joerg

Publisher: KIT Scientific Publishing

Published: 2014-09-19

Total Pages: 231

ISBN-13: 3731502461

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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.


Electrochemical Performance and Stability of Ba₀.₅Sr₀.₅Co₀.₈Fe₀.₂O₃₋δ for Oxygen Transport Membranes

Electrochemical Performance and Stability of Ba₀.₅Sr₀.₅Co₀.₈Fe₀.₂O₃₋δ for Oxygen Transport Membranes

Author: Niedrig, Christian

Publisher: KIT Scientific Publishing

Published: 2015-12-23

Total Pages: 206

ISBN-13: 3731504375

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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.


Theoretical Analysis of Electrochemical Energy Conversion Systems

Theoretical Analysis of Electrochemical Energy Conversion Systems

Author: S. B. GREENE

Publisher:

Published: 1962

Total Pages: 1

ISBN-13:

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Using the concepts of modern electrode kinetic theory, equations which express the currentvoltage discharge curve and power output of a cell in terms of the kinetic parameters of the individual electrodes are derived. Two new cell parameters are defined which permit the easy characterization and comparison of cell performances. Methods for determining the presence and effects of internal resistance and concentration polarization by analysis of discharge curves are described. Two novel methods for determining the value of the internal resistance of a cell are demonstrated. Experimental verification of the theoreticl concepts and equations is presented. (Author).


Impedance Spectroscopy

Impedance Spectroscopy

Author: Olfa Kanoun

Publisher: Walter de Gruyter GmbH & Co KG

Published: 2018-12-17

Total Pages: 203

ISBN-13: 3110558920

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Impedance Spectroscopy is a powerful measurement method used in many application fields such as electrochemistry, material science, biology and medicine, semiconductor industry and sensors. Using the complex impedance at various frequencies increases the informational basis that can be gained during a measurement. It helps to separate different effects that contribute to a measurement and, together with advanced mathematical methods, non-accessible quantities can be calculated. This book covers new advances in the field of impedance spectroscopy including fundamentals, methods and applications. It releases scientific contributions from the International Workshop on Impedance Spectroscopy (IWIS) as extended chapters including detailed information about recent scientific research results. The book includes typically subsections on: Fundamental of Impedance Spectroscopy Bio impedance Techniques and Applications Impedance Spectroscopy for Energy Storage Systems Sensors Based on Impedance Spectroscopy Measurement systems Excitation Signals Modeling Parameter extraction


Physical Multiscale Modeling and Numerical Simulation of Electrochemical Devices for Energy Conversion and Storage

Physical Multiscale Modeling and Numerical Simulation of Electrochemical Devices for Energy Conversion and Storage

Author: Alejandro A. Franco

Publisher: Springer

Published: 2015-11-12

Total Pages: 253

ISBN-13: 1447156773

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The aim of this book is to review innovative physical multiscale modeling methods which numerically simulate the structure and properties of electrochemical devices for energy storage and conversion. Written by world-class experts in the field, it revisits concepts, methodologies and approaches connecting ab initio with micro-, meso- and macro-scale modeling of components and cells. It also discusses the major scientific challenges of this field, such as that of lithium-ion batteries. This book demonstrates how fuel cells and batteries can be brought together to take advantage of well-established multi-scale physical modeling methodologies to advance research in this area. This book also highlights promising capabilities of such approaches for inexpensive virtual experimentation. In recent years, electrochemical systems such as polymer electrolyte membrane fuel cells, solid oxide fuel cells, water electrolyzers, lithium-ion batteries and supercapacitors have attracted much attention due to their potential for clean energy conversion and as storage devices. This has resulted in tremendous technological progress, such as the development of new electrolytes and new engineering designs of electrode structures. However, these technologies do not yet possess all the necessary characteristics, especially in terms of cost and durability, to compete within the most attractive markets. Physical multiscale modeling approaches bridge the gap between materials’ atomistic and structural properties and the macroscopic behavior of a device. They play a crucial role in optimizing the materials and operation in real-life conditions, thereby enabling enhanced cell performance and durability at a reduced cost. This book provides a valuable resource for researchers, engineers and students interested in physical modelling, numerical simulation, electrochemistry and theoretical chemistry.


Electrochemical Impedance

Electrochemical Impedance

Author: John R. Scully

Publisher: ASTM International

Published: 1993

Total Pages: 477

ISBN-13: 0803118619

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The collection of twenty-seven papers published has been grouped into six major categories : corrosion process characterization and modeling, applications of Kramers-Kronig transformations for evaluating the validity of data, corrosion and its inhibition by either corrosion products of specially added inhibitors, corrosion of aluminum and aluminum alloys, corrosion of steel in soils and concrete, and evaluation of coatings on metal substrates.