Thermo-mechanical Behavior of Lithium-ion Battery Electrodes
Title | Thermo-mechanical Behavior of Lithium-ion Battery Electrodes PDF eBook |
Author | Kai An |
Publisher | |
Pages | |
Release | 2014 |
Genre | |
ISBN |
Developing electric vehicles is widely considered as a direct approach to resolve the energy and environmental challenges faced by the human race. As one of the most promising power solutions to electric cars, the lithium ion battery is expected to achieve better performance, durability and safety. Fracture induced by lithiation and deliathiation stress has been identified as a major mechanism that leads to capacity loss and performance degradation. This work aims to shed light on the thermo-mechanical behavior of lithium ion battery electrodes. It presents a single particle model of random lattice spring elements coupled with solid phase Li-ion diffusion under active temperature effects. The thermal features are realized by solving a lumped heat conduction equation and by including temperature dependent parameters. This model combined with a typical equivalent-circuit model is used to predict the impedance response of electrode particles. The fracture generation increases as the temperature decreases. However, the diffusion induced fracture is found to be proportional to the current density and particle sizes. Simulations under realistic driving conditions show that the fraction of particle damage is determined by the highest current density drawn from the battery. A 3D phase map of fracture damage is presented. The transit fracture growing process reveals a saturation phenomenon where the fraction of damage increases to a threshold value and then stabilizes. This is observed both during single discharging processes and in multiple cycle simulations. In the multicycle analysis, the charging process following the initial discharging leads to a "re-saturation" where the fracture experiences a second increase and then stops growing ever after. The impedance study suggests that the generation of fracture leads to increase in impedance response of electrode particles. The calculated impedance results are found to be directly related to current density and particle size but drops with increasing temperatures. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151869
Mechanical Behavior of Lithium-ion Battery Electrodes - Experimental and Statistical Finite Element Analyses
Title | Mechanical Behavior of Lithium-ion Battery Electrodes - Experimental and Statistical Finite Element Analyses PDF eBook |
Author | İbrahim Buğra Üçel |
Publisher | |
Pages | 0 |
Release | 2023 |
Genre | |
ISBN | 9789180404495 |
Multi-scale Modeling of Lithium Ion Batteries
Title | Multi-scale Modeling of Lithium Ion Batteries PDF eBook |
Author | Ali Hossein Nezhad Shirazi |
Publisher | |
Pages | 0 |
Release | 2020 |
Genre | |
ISBN |
Rechargeable lithium ion batteries (LIBs) play a very significant role in power supply and storage. In recent decades, LIBs have caught tremendous attention in mobile communication, portable electronics, and electric vehicles. Furthermore, global warming has become a worldwide issue due to the ongoing production of greenhouse gases. It motivates solutions such as renewable sources of energy. Solar and wind energies are the most important ones in renewable energy sources. By technology progress, they will definitely require batteries to store the produced power to make a balance between power generation and consumption. Nowadays, rechargeable batteries such as LIBs are considered as one of the best solutions. They provide high specific energy and high rate performance while their rate of self-discharge is low. Performance of LIBs can be improved through the modification of battery characteristics. The size of solid particles in electrodes can impact the specific energy and the cyclability of batteries. It can improve the amount of lithium content in the electrode which is a vital parameter in capacity and capability of a battery. There exist diferent sources of heat generation in LIBs such as heat produced during electrochemical reactions, internal resistance in battery. The size of electrode's electroactive particles can directly affect the produced heat in battery. It will be shown that the smaller size of solid particle enhance the thermal characteristics of LIBs. Thermal issues such as overheating, temperature maldistribution in the battery, and thermal runaway have confined applications of LIBs. Such thermal challenges reduce the Life cycle of LIBs. As well, they may lead to dangerous conditions such as fire or even explosion in batteries. However, recent advances in fabrication of advanced materials such as graphene and carbon nanotubes with extraordinary thermal conductivity and electrical properties propose new opportunities to enhance their performance. Since experimental works are expensive, our objective is to use computational methods to investigate the thermal issues in LIBS. Dissipation of the heat produced in the battery can improve the cyclability and specific capacity of LIBs. In real applications, packs of LIB consist several battery cells that are used as the power source. Therefore, it is worth to investigate thermal characteristic of battery packs under their cycles of charging/discharging operations at different applied current rates. To remove the produced heat in batteries, they can be surrounded by materials with high thermal conductivity. Parafin wax absorbs high energy since it has a high latent heat. Absorption high amounts of energy occurs at constant temperature without phase change. As well, thermal conductivity of parafin can be magnified with nano-materials such as graphene, CNT, and fullerene to form a nano-composite medium. Improving the thermal conductivity of LIBs increase the heat dissipation from batteries which is a vital issue in systems of battery thermal management. The application of two-dimensional (2D) materials has been on the rise since exfoliation the graphene from bulk graphite. 2D materials are single-layered in an order of nanosizes which show superior thermal, mechanical, and optoelectronic properties. They are potential candidates for energy storage and supply, particularly in lithium ion batteries as electrode material. The high thermal conductivity of graphene and graphene-like materials can play a significant role in thermal management of batteries. However, defects always exist in nano-materials since there is no ideal fabrication process. One of the most important defects in materials are nano-crack which can dramatically weaken the mechanical properties of the materials. Newly synthesized crystalline carbon nitride with the stoichiometry of C3N have attracted many attentions due to its extraordinary mechanical and thermal properties. The other nano-material is phagraphene which shows anisotropic mechanical characteristics which is ideal in production of nanocomposite. It shows ductile fracture behavior when subjected under uniaxial loadings. It is worth to investigate their thermo-mechanical properties in its pristine and defective states. We hope that the findings of our work not only be useful for both experimental and theoretical researches but also help to design advanced electrodes for LIBs.
Nonlinear Solid Mechanics
Title | Nonlinear Solid Mechanics PDF eBook |
Author | Gerhard A. Holzapfel |
Publisher | |
Pages | 482 |
Release | 2000-04-06 |
Genre | Mathematics |
ISBN |
Providing a modern and comprehensive coverage of continuum mechanics, this volume includes information on "variational principles"--Significant, as this is the only method by which such material is actually utilized in engineering practice.
A Course on Damage Mechanics
Title | A Course on Damage Mechanics PDF eBook |
Author | Jean Lemaitre |
Publisher | Springer Science & Business Media |
Pages | 225 |
Release | 2013-12-14 |
Genre | Science |
ISBN | 3662027615 |
A new branch of science usually develops thus. Somebody publishes the basic ideas. Hesitatingly at first, then little by little, other original contributions appear, until a certain threshold is reached. Then, overview articles are printed, conferences are held, and a first mention is made in textbooks, until specialized monographs are written. Continuum darnage mechanics has reached that status now. To analyze or, if possible, to predict the failure of machine parts or other structures is one of the main goals of engineering science. Consequently fracture mechanics became one of its leading branches. It was based on the analysis of existing cracks. However, especially under conditions of cyclic loading, this might be too late to prevent a disaster. Therefore, the question regarding the precursory state, that is, the evolution of intemal darnage before macrocracks become visible, was then posed. One of the successful approaches to the problern was Weibull's theory which examined, in a statistical manner, the "weakest link" in the material volume under consideration. Unfortunately it proved too difficult mathematically to be applied to complicated parts or structures. Therefore it was highly appreciated by the scientific of material community when L. M. Kachanov published in 1958 a simple model darnage which subsequently could be extended to brittle elastic, plastic or viscous materials under all conditions of uniaxial or multiaxial, simple or cyclic loadings, so that it may be considered nearly universal.
The Finite Element Method
Title | The Finite Element Method PDF eBook |
Author | Thomas J. R. Hughes |
Publisher | Courier Corporation |
Pages | 706 |
Release | 2012-05-23 |
Genre | Technology & Engineering |
ISBN | 0486135020 |
Designed for students without in-depth mathematical training, this text includes a comprehensive presentation and analysis of algorithms of time-dependent phenomena plus beam, plate, and shell theories. Solution guide available upon request.
Coupling of Mechanical Behavior of Lithium Ion Cells to Electrochemical-Thermal Models for Battery Crush
Title | Coupling of Mechanical Behavior of Lithium Ion Cells to Electrochemical-Thermal Models for Battery Crush PDF eBook |
Author | |
Publisher | |
Pages | 0 |
Release | 2015 |
Genre | |
ISBN |
Vehicle crashes can lead to crushing of the battery, damaging lithium ion battery cells and causing local shorts, heat generation, and thermal runaway. Simulating all the physics and geometries at the same time is challenging and takes a lot of effort; thus, simplifications are needed. We developed a material model for simultaneously modeling the mechanical-electrochemical-thermal behavior, which predicted the electrical short, voltage drop, and thermal runaway behaviors followed by a mechanical abuse-induced short. The effect of short resistance on the battery cell performance was studied.