Download or read book Mathematical Analysis of the Lithium Ion Transport in Lithium Ion Batteries Using Three Dimensional Reconstructed Electrodes written by Cheol Woong Lim and published by . This book was released on 2012 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational analysis of lithium ion batteries has been improved since Newman and et al. suggested the porous electrode theory. It assumed the electrode as a simple structure of homogeneous spherical particles. Bruggeman relationship which characterizes porous material by a simple equation was adopted in the homogeneous electrode model instead of the electrode morphology. To improve the prediction of a cell performance, the numerical analysis requires the realistic microstructure of the cell. Based on the experimentally determined microstructure of the positive and negative electrodes of a lithium ion battery (LIB) using x-ray micro/nano-CT technology, three dimensional (3D) simulations have been presented in this research. Tortuosity of the microstructures has been calculated by a linear diffusion equation to characterize the 3D morphology. The obtained tortuosity and porosity results pointed out that the Bruggeman relationship is not sufficiently estimate the tortuosity by the porosity of electrodes. We studied the diffusion-induced stress numerically based on realistic morphology of reconstructed particles during the lithium ion intercalation process. Diffusion-induced stresses were simulated at different C rates under galvonostatic conditions and compared with spherical particles. The simulation results showed that the intercalation stresses of particles depend on their geometric characteristics. The highest von Mises stress and tresca stress in a real particle are several times higher than the stresses in a spherical particle with the same volume. With the reconstructed positive electrode structure, local effects in the LIB cathode electrode during galvanostatic discharge process have been studied. The simulation results reported that large current density usually occurs at the joints between cathode active material particles and in the small channels in electrolyte, which will generate high electric joule power. By using the 3D real image of a LIB cathode electrode, numerical simulation results revealed that the spatial distribution of variable fields such as concentration, voltage, reaction rate, overpotential, and etc. in the cathode electrode are complicated and non-uniform, especially at high discharge rates.

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 Modeling transport properties and electrochemical performance of hierarchically structured lithium ion battery cathodes using resistor networks and mathematical half cell models written by Birkholz, Oleg and published by KIT Scientific Publishing. This book was released on 2022-10-05 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hierarchically structured active materials in electrodes of lithium-ion cells are promising candidates for increasing gravimetric energy density and improving rate capability of the system. To investigate the influence of cathode structures on the performance of the whole cell, efficient tools for calculating effective transport properties of granular systems are developed and their influence on the electrochemical performance is investigated in specially adapted cell models.

Download or read book Electrochemical Transport Simulation of 3D Lithium ion Battery Electrode Microstructures written by Bradley Louis Trembacki and published by . This book was released on 2015 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lithium-ion batteries are commonly modeled using a volume-averaged formulation (porous electrode theory) in order to simulate battery behavior on a large scale. These methods utilize effective material properties and assume a simplified spherical geometry of the electrode particles. In contrast, a particle-scale (non-porous electrode) simulation applied to resolved electrode geometries predicts localized phenomena. Complete simulations of batteries require a coupling of the two scales to resolve the relevant physics. A central focus of this thesis is to develop a fully-coupled finite volume methodology for the simulation of the electrochemical equations in a lithium-ion battery cell at both the particle scale and using volume-averaged formulations. Due to highly complex electrode geometries at the particle scale, the formulation employs an unstructured computational mesh and is implemented within the MEMOSA software framework of Purdue’s PRISM (Prediction of Reliability, Integrity and Survivability of Microsystems) center. Stable and efficient algorithms are developed for full coupling of the nonlinear species transport equations, electrostatics, and Butler-Volmer kinetics. The model is applied to synthetic electrode particle beds for comparison with porous electrode theory simulations and to evaluate numerical performance capabilities. The model is also applied to a half-cell mesh created from a real cathode particle bed reconstruction to demonstrate the feasibility of such simulations. The second focus of the thesis is to investigate 3D battery electrode architectures that offer potential energy density and power density improvements over traditional particle bed battery geometries. A singular feature of these geometries is their interpenetrating nature, which significantly reduces diffusion distance. Advancement of micro-scale additive manufacturing techniques has made it possible to fabricate these electrode microarchitectures. A fully-coupled finite volume methodology for the transport equations coupled to the relevant electrochemistry is implemented in the PETSc (Portable, Extensible Toolkit for Scientific Computation) software framework which allows for a straightforward scalable simulation on orthogonal hexahedral meshes. Such scalability becomes important when performing simulations on fully resolved microstructures with many parameter sweeps across multiple variables. Using the computational model, a variety of 3D battery electrode geometries are simulated and compared across various battery discharge rates and length scales in order to quantify performance trends and investigate geometrical factors that improve battery performance. The energy density and power density of the 3D battery microstructures are compared in several ways, including a uniform surface area to volume ratio comparison as well as a comparison requiring a minimum manufacturable feature size. Significant performance improvements over traditional particle bed electrode designs are observed, and electrode microarchitectures derived from minimal surfaces are shown to be superior under a minimum feature size constraint. An average Thiele modulus formulation is presented to predict the performance trends of 3D microbattery electrode geometries. As a natural extension of the 3D battery particle-scale modeling, the third and final focus of the thesis is the development and evaluation of a volume-averaged porous electrode theory formulation for these unique 3D interpenetrating geometries. It is necessary to average all three material domains (anode, cathode, and electrolyte) together, in contrast to traditional two material volume-averaging formulations for particle bed geometries. This model is discretized and implemented in the PETSc software framework in a manner similar to the particle-scale implementation and enables battery-level simulations of interpenetrating 3D battery electrode architectures. Electrode concentration gradients are modeled using a characteristic diffusion length, and results for plate and cylinder electrode geometries are compared to particle-scale simulation results. Additionally, effective diffusion lengths that minimize error with respect to particle-scale results for gyroid and Schwarz P electrode microstructures are determined, since a theoretical single diffusion length is not easily calculated. Using these models, the porous electrode formulation for these 3D interpenetrating geometries is shown to match the results of particle-scale models very well.

Download or read book Mathematical Modeling of Lithium Ion Batteries and Cells written by V. Subramanian and published by The Electrochemical Society. This book was released on 2012 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Multiscale Modeling and Numerical Simulation of Electrochemical Devices for Energy Conversion and Storage written by Alejandro A. Franco and published by Springer. This book was released on 2015-11-12 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Mathematical Modeling of Lithium Batteries written by Krishnan S. Hariharan and published by Springer. This book was released on 2017-12-28 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is unique to be the only one completely dedicated for battery modeling for all components of battery management system (BMS) applications. The contents of this book compliment the multitude of research publications in this domain by providing coherent fundamentals. An explosive market of Li ion batteries has led to aggressive demand for mathematical models for battery management systems (BMS). Researchers from multi-various backgrounds contribute from their respective background, leading to a lateral growth. Risk of this runaway situation is that researchers tend to use an existing method or algorithm without in depth knowledge of the cohesive fundamentals—often misinterpreting the outcome. It is worthy to note that the guiding principles are similar and the lack of clarity impedes a significant advancement. A repeat or even a synopsis of all the applications of battery modeling albeit redundant, would hence be a mammoth task, and cannot be done in a single offering. The authors believe that a pivotal contribution can be made by explaining the fundamentals in a coherent manner. Such an offering would enable researchers from multiple domains appreciate the bedrock principles and forward the frontier. Battery is an electrochemical system, and any level of understanding cannot ellipse this premise. The common thread that needs to run across—from detailed electrochemical models to algorithms used for real time estimation on a microchip—is that it be physics based. Build on this theme, this book has three parts. Each part starts with developing a framework—often invoking basic principles of thermodynamics or transport phenomena—and ends with certain verified real time applications. The first part deals with electrochemical modeling and the second with model order reduction. Objective of a BMS is estimation of state and health, and the third part is dedicated for that. Rules for state observers are derived from a generic Bayesian framework, and health estimation is pursued using machine learning (ML) tools. A distinct component of this book is thorough derivations of the learning rules for the novel ML algorithms. Given the large-scale application of ML in various domains, this segment can be relevant to researchers outside BMS domain as well. The authors hope this offering would satisfy a practicing engineer with a basic perspective, and a budding researcher with essential tools on a comprehensive understanding of BMS models.

Download or read book Modeling of Transport in Lithium Ion Battery Electrodes written by Michael Martin and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lithium ion battery systems are promising solutions to current energy storage needs due to their high operating voltage and capacity. Numerous efforts have been conducted to model these systems in order to aid the design process and avoid expensive and time consuming prototypical experiments. Of the numerous processes occurring in these systems, solid state transport in particular has drawn a large amount of attention from the research community, as it tends to be one of the rate limiting steps in lithium ion battery performance. Recent studies have additionally indicated that purposeful design of battery electrodes using 3D microstructures offers new freedoms in design, better use of available cell area, and increased battery performance. The following study is meant to serve as a first principles investigation into the behaviors of 3D electrode architectures by monitoring concentration and cycle behaviors under realistic operating conditions. This was accomplished using computational tools to model the solid state diffusion behavior in several generated electrode morphologies. Developed computational codes were used to generate targeted structures under prescribed conditions of particle shape, size, and overall morphology. The diffusion processes in these morphologies were simulated under conditions prescribed from literature. Primary results indicate that parameters usually employed to describe electrode geometry, such as volume to surface area ratio, cannot be solely relied upon to predict or characterize performance. Additionally, the interaction between particle shapes implies some design aspects that may be exploited to improve morphology behavior. Of major importance is the degree of particle isolation and overlap in 3D architectures, as these govern gradient development and lithium depletion within the electrode structures. The results of this study indicate that there are optimum levels of these parameters, and so purposeful design must make use of these behaviors.

Download or read book Electrochemical Systems written by John Newman and published by John Wiley & Sons. This book was released on 2012-11-27 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: The new edition of the cornerstone text on electrochemistry Spans all the areas of electrochemistry, from the basicsof thermodynamics and electrode kinetics to transport phenomena inelectrolytes, metals, and semiconductors. Newly updated andexpanded, the Third Edition covers important new treatments, ideas,and technologies while also increasing the book's accessibility forreaders in related fields. Rigorous and complete presentation of the fundamentalconcepts In-depth examples applying the concepts to real-life designproblems Homework problems ranging from the reinforcing to the highlythought-provoking Extensive bibliography giving both the historical developmentof the field and references for the practicing electrochemist.

Download or read book Three Dimensional Lithium Ion Battery Model Presentation written by and published by . This book was released on 2008 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonuniform battery physics can cause unexpected performance and life degradations in lithium-ion batteries; a three-dimensional cell performance model was developed by integrating an electrode-scale submodel using a multiscale modeling scheme.

Download or read book Three Dimensional Characterization of Failure Evolution of Tin and Silicon in Lithium Ion Battery Electrodes written by Joseph Fernando Gonzalez and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Lithium ion Battery Model written by Gi-Heon Kim and published by . This book was released on 2008 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonuniform battery physics can cause unexpected performance and life degradations in lithium-ion batteries; a three-dimensional cell performance model was developed by integrating an electrode-scale submodel using a multiscale modeling scheme.

Download or read book Investigation of Lithium Ion Battery Electrodes written by Nicholas William Brady and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Further investigation of the LiV3O8 electrode is undertaken by coupling the crystal scale model to electrode scale phenomena. Characterization of the LiV3O8 electrode by operando EDXRD experiments provides a unique and independent set of observations that validate the previously estimated physical constants for the phase change saturation concentration and phase change reaction rate constant; they are both found to be consistent with their previous estimates. Finally, it is observed that anodic physical phenomena are important during delithiation of the cathode because the kinetics at the anode become mass-transfer limited. Finally, it is illustrated that coupling physical models to data science and algorithmic computing is an effective method to accelerate model development and quantitatively guide the design of experiments.

Download or read book Efficient Simulation and Model Reformulation of Two dimensional Electrochemical Thermal Behavior of Lithium ion Batteries written by and published by . This book was released on 2015 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lithium-ion batteries are an important technology to facilitate efficient energy storage and enable a shift from petroleum based energy to more environmentally benign sources. Such systems can be utilized most efficiently if good understanding of performance can be achieved for a range of operating conditions. Mathematical models can be useful to predict battery behavior to allow for optimization of design and control. An analytical solution is ideally preferred to solve the equations of a mathematical model, as it eliminates the error that arises when using numerical techniques and is usually computationally cheap. An analytical solution provides insight into the behavior of the system and also explicitly shows the effects of different parameters on the behavior. However, most engineering models, including the majority of battery models, cannot be solved analytically due to non-linearities in the equations and state dependent transport and kinetic parameters. The numerical method used to solve the system of equations describing a battery operation can have a significant impact on the computational cost of the simulation. In this paper, a model reformulation of the porous electrode pseudo three dimensional (P3D) which significantly reduces the computational cost of lithium ion battery simulation, while maintaining high accuracy, is discussed. This reformulation enables the use of the P3D model into applications that would otherwise be too computationally expensive to justify its use, such as online control, optimization, and parameter estimation. Furthermore, the P3D model has proven to be robust enough to allow for the inclusion of additional physical phenomena as understanding improves. In this study, the reformulated model is used to allow for more complicated physical phenomena to be considered for study, including thermal effects.

Download or read book Phase Transitions in Insertion Electrodes for Lithium Batteries written by and published by . This book was released on 2000 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase transitions that occur during lithium insertion into layered and framework structures are discussed in the context of their application as positive and negative electrodes in lithium-ion batteries. The discussion is focused on the two-dimensional structures of graphite, LiNi{sub 1-x}M(subscript x)O2 (M = Co, Ti and Mg), and Li{sub 1.2}V3O; examples of framework structures with a three-dimensional interstitial space for Li-ion transport include the spinel oxides and intermetallic compounds with zinc-blende-type structures. The phase transitions are discussed in terms of their tolerance to lithium insertion and extraction and to the chemical stability of the electrodes in the cell environment.

Download or read book Electron Backscatter Diffraction in Materials Science written by Adam J. Schwartz and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystallographic texture or preferred orientation has long been known to strongly influence material properties. Historically, the means of obtaining such texture data has been though the use of x-ray or neutron diffraction for bulk texture measurements, or transmission electron microscopy or electron channeling for local crystallographic information. In recent years, we have seen the emergence of a new characterization technique for probing the microtexture of materials. This advance has come about primarily through the automated indexing of electron backscatter diffraction (EBSD) patterns. The first commercially available system was introduced in 1994, and since then of sales worldwide has been dramatic. This has accompanied widening the growth applicability in materials scienceproblems such as microtexture, phase identification, grain boundary character distribution, deformation microstructures, etc. and is evidence that this technique can, in some cases, replace more time-consuming transmission electron microscope (TEM) or x-ray diffraction investigations. The benefits lie in the fact that the spatial resolution on new field emission scanning electron microscopes (SEM) can approach 50 nm, but spatial extent can be as large a centimeter or greater with a computer controlled stage and montagingofthe images. Additional benefits include the relative ease and low costofattaching EBSD hardware to new or existing SEMs. Electron backscatter diffraction is also known as backscatter Kikuchi diffraction (BKD), or electron backscatter pattern technique (EBSP). Commercial names for the automation include Orientation Imaging Microscopy (OIMTM) and Automated Crystal Orientation Mapping (ACOM).

Download or read book Modeling and State Estimation of Automotive Lithium Ion Batteries written by Shunli Wang and published by CRC Press. This book was released on 2024-07-16 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book aims to evaluate and improve the state of charge (SOC) and state of health (SOH) of automotive lithium-ion batteries. The authors first introduce the basic working principle and dynamic test characteristics of lithium-ion batteries. They present the dynamic transfer model, compare it with the traditional second-order reserve capacity (RC) model, and demonstrate the advantages of the proposed new model. In addition, they propose the chaotic firefly optimization algorithm and demonstrate its effectiveness in improving the accuracy of SOC and SOH estimation through theoretical and experimental analysis. The book will benefit researchers and engineers in the new energy industry and provide students of science and engineering with some innovative aspects of battery modeling.