Download or read book Molecular Dynamics Simulation Studies of Ionic Liquids Electrolytes for Lithium Ion Batteries written by Zhe Li and published by . This book was released on 2012 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Na ion Batteries written by and published by John Wiley & Sons. This book was released on 2021-05-11 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers both the fundamental and applied aspects of advanced Na-ion batteries (NIB) which have proven to be a potential challenger to Li-ion batteries. Both the chemistry and design of positive and negative electrode materials are examined. In NIB, the electrolyte is also a crucial part of the batteries and the recent research, showing a possible alternative to classical electrolytes – with the development of ionic liquid-based electrolytes – is also explored. Cycling performance in NIB is also strongly associated with the quality of the electrode-electrolyte interface, where electrolyte degradation takes place; thus, Na-ion Batteries details the recent achievements in furthering knowledge of this interface. Finally, as the ultimate goal is commercialization of this new electrical storage technology, the last chapters are dedicated to the industrial point of view, given by two startup companies, who developed two different NIB chemistries for complementary applications and markets.

Download or read book Theoretical Insights into the Electrochemical Properties of Ionic Liquid Electrolytes in Lithium Ion Batteries written by Leila Maftoon-Azad and published by CRC Press. This book was released on 2024-09-17 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a concise overview of the use of ionic liquids as electrolytes in lithium-ion batteries (LIBs) from a theoretical and computational perspective. It focuses on computational studies to understand the behavior of lithium ions in different ionic liquids and to optimize the performance of ionic liquid-based electrolytes. The main features of the book are as follows: • Provides a thorough understanding of the theoretical and computational aspects of using ionic liquids as electrolytes in LIBs, including the evaluation and reproducibility of the theoretical paths. • Covers various computational methods such as density functional theory, molecular dynamics, and quantum mechanics that have been used to study the behavior of lithium ions in different solvents and to optimize the performance of ionic liquid-based electrolytes. • Discusses recent advances such as new computational methods for predicting the properties of ionic liquid-based electrolytes, new strategies for improving the stability and conductivity of these electrolytes, and new approaches for understanding the kinetics and thermodynamics of redox reactions with ionic liquids. • Suggests how theoretical insights can be translated into practical applications for improving performance and safety. This monograph will be of interest to engineers working on LIB optimization.

Download or read book Studies of Interactions Between Ions in Ionics Liquids Electrolytes by Nuclear Magnetic Resonance written by Pierre Martin (Chimiste).) and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work is focused on the study of electrolytes for energy storage devices such as lithium ion batteries. The specific materials are pyrrolidinium-based ionic liquid electrolytes with bis-fluorosulfonylimide (FSI) as the counter anion, and also containing lithium.The main experimental method of characterization is Nuclear Magnetic Resonance (NMR) spectroscopy, which can be used to probe structure, dynamics and spatial arrangements between anions and cations. NMR-based diffusion measurements or spin lattice relaxation experiments, using 1H for cations, 19F for anions and 7Li, are used to study the ionic transport in the liquid and the molecular tumbling of the different ions respectively.However, in order to attempt to better understand the ion transport mechanism at the molecular level in these ionic liquids, the HOESY (Heteronuclear Overhauser Effect SpectroscopY) experiment is used. This technique is based on a transfer of magnetization through space between two different nuclear isotopes. As this transfer is generally mediated by short-range interactions, it provides information on which species are close together in the liquid.A large part of this work is based on the development of the HOESY technique itself, both improving the implementation of the NMR pulse sequence to reduce the experimental time, but also improving ways to analyze the resulting data in a quantitative way and developing an automatic and systematic data fitting procedure. Molecular Dynamics (MD) simulations and NMR relaxation measurements are also used to assist the HOESY analysis, allowing correlations with distances between nuclei and motional parameters such as correlation times to be established, which will lead to a better understanding of the ion interactions. In addition to this technique development, others ionic liquids including longer alkyl, longer cycle or even an ether-o-alkyl group on the alkyl chain, are studied by HOESY in order to observe the impact of the cation structure on the ionic interactions. Another complementary technique, dynamic nuclear polarization, is also used in order to study the ionic liquid in the glassy state structure which mimics the liquid state.

Download or read book Electrolytes for Lithium and Lithium Ion Batteries written by T. Richard Jow and published by Springer. This book was released on 2014-05-06 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrolytes for Lithium and Lithium-ion Batteries provides a comprehensive overview of the scientific understanding and technological development of electrolyte materials in the last several years. This book covers key electrolytes such as LiPF6 salt in mixed-carbonate solvents with additives for the state-of-the-art Li-ion batteries as well as new electrolyte materials developed recently that lay the foundation for future advances. This book also reviews the characterization of electrolyte materials for their transport properties, structures, phase relationships, stabilities, and impurities. The book discusses in-depth the electrode-electrolyte interactions and interphasial chemistries that are key for the successful use of the electrolyte in practical devices. The Quantum Mechanical and Molecular Dynamical calculations that has proved to be so powerful in understanding and predicating behavior and properties of materials is also reviewed in this book. Electrolytes for Lithium and Lithium-ion Batteries is ideal for electrochemists, engineers, researchers interested in energy science and technology, material scientists, and physicists working on energy.

Download or read book Atomistic Modeling of Ionic Liquid Based Electrolytes for Lithium Batteries written by Anirudh Deshpande 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 Ionic Liquid Crystals written by Giacomo Saielli and published by MDPI. This book was released on 2019-06-24 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book we have collected a series of state-of-the art papers written by specialists in the field of ionic liquid crystals (ILCs) to address key questions concerning the synthesis, properties, and applications of ILCs. New compounds exhibiting ionic liquid crystalline phases are presented, both of calamitic as well as discotic type. Their dynamic and structural properties have been investigated with a series of experimental techniques including differential scanning calorimetry, polarized optical spectroscopy, X-ray scattering, and nuclear magnetic resonance, impedance spectroscopy to mention but a few. Moreover, computer simulations using both fully atomistic and highly coarse-grained force fields have been presented, offering an invaluable microscopic view of the structure and dynamics of these fascinating materials.

Download or read book Liquid Electrolyte Chemistry for Lithium Metal Batteries written by Jianmin Ma and published by John Wiley & Sons. This book was released on 2022-02-09 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid Electrolyte Chemistry for Lithium Metal Batteries An of-the-moment treatment of liquid electrolytes used in lithium metal batteries Considered by many as the most-promising next-generation batteries, lithium metal batteries have grown in popularity due to their low potential and high capacity. Crucial to the development of this technology, electrolytes can provide efficient electrode electrolyte interfaces, assuring the interconversion of chemical and electrical energy. The quality of electrode electrolyte interphase, in turn, directly governs the performance of batteries. In Liquid Electrolyte Chemistry, provides a comprehensive look at the current understanding and status of research regarding liquid electrolytes for lithium metal batteries. Offering an introduction to lithium-based batteries from development history to their working mechanisms, the book further offers a glimpse at modification strategies of anode electrolyte interphases and cathode electrolytic interphases. More, by discussing the high-voltage electrolytes from their solvents—organic solvents and ionic liquids—to electrolyte additives, the text provides a thorough understanding on liquid electrolyte chemistry in the remit of lithium metal batteries. Liquid Electrolyte Chemistry for Lithium Metal Batteries readers will also find: A unique focus that reviews the development of liquid electrolytes for lithium metal batteries State-of-the-art progress and development of electrolytes for lithium metal batteries Consideration of safety, focusing the design principles of flame retardant and non-flammable electrolytes Principles and progress on low temperature and high temperature electrolytes Liquid Electrolyte Chemistry for Lithium Metal Batteries is a useful reference for electrochemists, solid state chemists, inorganic chemists, physical chemists, surface chemists, materials scientists, and the libraries that supply them.

Download or read book Polymerized Ionic Liquids written by Ali Eftekhari and published by Royal Society of Chemistry. This book was released on 2017-09-18 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series covers the fundamentals and applications of different smart material systems from renowned international experts.

Download or read book Molten Salts and Ionic Liquids written by Marcelle Gaune-Escard and published by John Wiley & Sons. This book was released on 2012-07-06 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many years, the related fields of molten salts and ionic liquids have drifted apart, to their mutual detriment. Both molten salts and ionic liquids are liquid salts containing only ions - all that is different is the temperature! Both fields involve the study of Coulombic fluids for academic and industrial purposes; both employ the same principles; both require skilled practitioners; both speak the same language; all then that is truly different is their semantics, and how superficial is that? The editors of this book, recognising that there was so much knowledge, both empirical and theoretical, which can be passed from the molten salt community to the ionic liquid community, and vice versa, organised a landmark meeting in Tunisia, designed to bridge the gap and heal the rift. Leaders from both communities met for a week for a mutual exchange, with a high tutorial content intermixed with cutting edge findings. This volume is a condensate of the principal offerings of that week, and emphasises the success which was achieved. Indeed, four future biannual meetings, under the title of “EUCHEM Conferences on Molten Salts and Ionic Liquids”, have now been planned as a direct result of this meeting of minds. Topics discussed in this volume include structure, dynamics, electrochemistry, interfacial and thermodynamic properties, spectroscopy, synthesis, and theoretical studies. Experimental and theoretical methods for investigating these data are elaborated, as are techniques for data collection and analysis. This book represents the first serious discussion on the transfer of these methods and techniques between the differing temperature regimes, and is a major contribution to the future of both fields.

Download or read book Energy Storage and Conversion Materials written by Stephen Skinner and published by Royal Society of Chemistry. This book was released on 2019-11-22 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy Storage and Conversion Materials describes the application of inorganic materials in the storage and conversion of energy.

Download or read book Structures and Interactions of Ionic Liquids written by Suojiang Zhang and published by Springer. This book was released on 2013-12-20 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structures, Bonding and Hydrogen Bonds, by Kun Dong, Qian Wang, Xingmei Lu, Suojiang Zhang Aggregation in System of Ionic Liquids, by Jianji Wang, Huiyong Wang Dissolution of Biomass Using Ionic Liquids, by Hui Wang, Gabriela Gurau, Robin D. Rogers Effect of the Structures of Ionic Liquids on Their Physical-Chemical Properties, by Yu-Feng Hu, Xiao-Ming Peng Microstructure study of Ionic liquids by spectroscopy, by Haoran Li Structures and Thermodynamic Properties of Ionic Liquids, by Tiancheng Mu, Buxing Han

Download or read book Reactive Molecular Dynamics Simulations of Lithium Secondary Batteries Interfaces and Electrodes written by Md Mahbubul Islam and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last two decades, lithium-based batteries have revolutionized the energy storage technologies. Li-ion batteries have found widespread use in portable electronics and electric vehicle applications. However, a detailed understanding of the battery chemistry, especially the formation of a solid electrolyte interphase (SEI)a thin passivation layer which is generated during the first charge cycle due to the reduction of electrolytesis still elusive. The mass scale commercialization of electric vehicles requires the storage capacity beyond the conventional Li-ion batteries, which spurred research interests towards Li-S technologies. Li-S batteries are attractive for their very high capacity and energy density, but their commercial application has been thwarted due to several critical limitations stemming from electrolyte dissociation chemistry and electrode material properties. To investigate the current issues associated with the Li-ion and Li-S batteries and to find possible countermeasures, we used both a newly developed computational tool eReaxFF and the standard ReaxFF reactive molecular dynamics simulations in the following research areas:1) We developed a computational method, eReaxFF, for simulating explicit electrons within the framework of the standard ReaxFF reactive force field method. We treat electrons explicitly in a pseudoclassical manner that enables simulation several orders of magnitude faster than quantum chemistry (QC) methods, while retaining the ReaxFF transferability. We describe in this thesis the fundamental concepts of the eReaxFF method, and the integration of the Atom-condensed Kohn-Sham DFT approximated to second order (ACKS2) charge calculation scheme into the eReaxFF. We trained our force field to capture electron affinities (EA) of various species. As a proof-of-principle, we performed a set of molecular dynamics (MD) simulations with an explicit electron model for representative hydrocarbon radicals. We establish a good qualitative agreement of EAs of various species with experimental data, and MD simulations with eReaxFF agree well with the corresponding Ehrenfest dynamics simulations. The standard ReaxFF parameters available in literature are transferrable to the eReaxFF method. The computationally economic eReaxFF method will be a useful tool for studying large-scale chemical and physical systems with explicit electrons as an alternative to computationally demanding QC methods. 2) A detailed understanding of the mechanism of the formation of SEI is crucial for designing high capacity and longer lifecycle lithium-ion batteries. The anode side SEI is primarily comprised of the reductive dissociation products of the electrolyte molecules. Any accurate computational method to study the reductive decomposition mechanism of electrolyte molecules is required to possess an explicit electronic degree of freedom. In this study, we employed our newly developed eReaxFF method to investigate the major reduction reaction pathways of SEI formation with ethylene carbonate (EC) based electrolytes. In the eReaxFF method, a pseudo-classical treatment of electrons provides the capability to simulate explicit electrons in a complex reactive environment. Our eReaxFF predicted simulation results of the EC decomposition reactions are in good agreement with the quantum chemistry data available in literature. Our MD simulations capture the mechanism of the reduction of the EC molecule due to the electron transfer from lithium, ring opening of the EC to generate EC-/Li+ radicals, and subsequent radical termination reactions. Our results indicate that the eReaxFF method is a useful tool for large-scale simulations to describe redox reactions occurring at electrode-electrolyte interfaces where quantum chemistry based methods are not viable due to their high computational requirement.3) Li-S batteries still suffer several formidable performance degradation issues that impede their commercial applications. The lithium negative electrode yields high anodic capacity, but it causes dendrite formation and raises safety concerns. Furthermore, the high reactivity of lithium is accountable for electrolyte decomposition. To investigate these issues and possible countermeasures, we used ReaxFF reactive molecular dynamics simulations to elucidate anode-electrolyte interfacial chemistry and utilized an ex-situ anode surface treatment with Teflon coating. In this study, we employed Li/SWCNT (single-wall carbon nanotube) composite anode instead of lithium metal and tetra (ethylene glycol) dimethyl ether (TEGDME) as electrolyte. We find that at a lithium rich environment of the anode-electrolyte interface, electrolyte dissociates and generates ethylene gas as a major reaction product, while utilization of Teflon layer suppresses the lithium reactivity and reduces electrolyte decomposition. Lithium discharge from the negative electrode is an exothermic event that creates local hot spots at the interfacial region and expedites electrolyte dissociation reaction kinetics. Usage of Teflon dampens initial heat flow and effectively reduces lithium reactivity with the electrolyte. 4) Sulfur cathodes of Li-S batteries undergo a noticeable volume variation upon cycling, which induces stress. In spite of intensive investigation of the electrochemical behavior of the lithiated sulfur compounds, their mechanical properties are not very well understood. In order to fill this gap, we developed a ReaxFF interatomic potential to describe Li-S interactions and performed MD simulations to study the structural, mechanical, and kinetic behavior of the amorphous lithiated sulfur (a-LixS) compounds. We examined the effect of lithiation on material properties such as ultimate strength, yield strength, and Youngs modulus. Our results suggest that with increasing lithium content, the strength of lithiated sulfur compounds improves, although this increment is not linear with the lithiation. The dependence of the mechanical properties and failure behavior on the loading rate of the amorphous lithiated sulfur compositions was also studied. The diffusion coefficients of both lithium and sulfur were computed for the a-LixS system at various stages of Li-loading. A Grand canonical Monte Carlo (GCMC) scheme was used to calculate the open circuit voltage (OCV) profile during cell discharge. The calculated OCV is consistent with prior experimental results. Our ReaxFF potentials also reproduced experimentally observed volume expansion of a-LixS phases upon lithiation. The Li-S binary phase diagram was constructed using genetic algorithm based tools. These simulation results provide insight into the behavior of sulfur-based cathode materials that are needed for developing high-performance lithium-sulfur batteries.

Download or read book Computer Simulation of Liquids written by M. P. Allen and published by Oxford University Press. This book was released on 1989 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer simulation is an essential tool in studying the chemistry and physics of liquids. Simulations allow us to develop models and to test them against experimental data. This book is an introduction and practical guide to the molecular dynamics and Monte Carlo methods.

Download or read book Molecular Dynamics Simulations of Ionic Liquids and Ionic Liquid conventional Solvent Mixtures written by Brian Conway and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation is comprised of three primary chapters which describe studies of the unique structure and dynamics present in ionic liquids and their mixtures with conventional solvents. Ionic liquids differ from conventional dipolar solvents in that consist of charge-separated ions, which allow for a richer variety of solvation structures than do dipolar solvents. Ionic liquids often have intriguing morphologies and dynamics, which are strongly influenced by the attractive and repulsive components of the constituent ions. When other solvents are added to create binary mixtures, these structural and dynamical peculiarities can be enhanced or largely eliminated. In this dissertation we examine ionic liquid structure and dynamics on a molecular level through molecular dynamics simulations. These simulations both help explain experimentally observed trends and provide new insights into these complex systems.Chapter 2 reports studies of the rotational behavior of 1-butyl-3-methylimidazolium tetrafluoroborate ([Im41][BF4]) mixed with acetonitrile (CH3CN). This study was performed in part to validate the dynamics of a force field later used to study solvation, but also out of interest in understanding the modes of motion by which the solvent or a benzene solute rotates. To do so, we compare experimental 2H T1 NMR relaxation times to simulated rotation times corresponding to various bond axes, which are directly related. The former reports only single time, which encompasses all relaxation mechanisms. In simulation, through calculation of a rotational correlation function, we observe the individual timescales on which various rotational axes relax. Some, like methyl groups, spin and relax very quickly, but slower modes, like those of the cation ring require tumbling motion to fully decorrelate from their initial orientation. We consider the timescales of these different types of motion and relate them to the friction on each motion, and reveal how each is related to solution viscosity.Chapter 3 uses the force fields validated in Chapter 2 to study the solvation structure and dynamics of the chromophore Coumarin 153 (C153) dissolved in [Im41][BF4] mixed with either CH3CN or H2O, as prototypical examples of dipolar aprotic and protic cosolvents. These conventional solvents serve to reduce the viscosity of the ionic liquids and make them more suitable for industrial use. Prior spectroscopic studies established the steady-state spectral shifts and time-resolved solvation response in these mixtures as functions of composition. The steady state spectra suggest that C153 is preferentially solvated in H2O in those mixtures, but the solute is insoluble in pure water. Here we focus on calculating analogs to the experimental values and using the atomistic detail of MD simulation to characterize the local solvation environment of C153 in these mixtures and isolate the solvent contributions responsible for the experimental observations, particularly those puzzling shifts in IL + H2O. In the CH3CN mixtures, the spectral shifts are unremarkable with solution composition. In this mixture, the ionic liquid and cosolvent mix essentially ideally, and the spectral shifts and dynamics indicate no preference for the C153 in either mixture component. However, in H2O, C153 is solvated almost entirely by ionic liquid. With increasing water concentration, the changes in the spectral shift can be isolated to contributions owing to H2O hydrogen-bound to a carbonyl on the chromophore. We conclude this work by explaining the motions that the solvent makes about C153 and how it relates to the observed spectral response.Chapter 4 discusses diffusion of small solutes in ionic liquids and dipolar solvents. Their diffusion reaches a curious regime in which the friction experienced by a solute drastically deviates from the Stokes-Einstein prediction. When the solute is much smaller than the solvent, neutral solutes diffuse much faster than expected and charged solutes much slower. Experimentally, this effect has been well documented. Here we try to explain these trends using MD simulation. By reducing our system to spherical single-site solutes, we simplify the interactions experienced. After reproducing the experimental trends, we examine solvation structure and how it gives rise to the observed differences between neutral and charged solute dynamics. Charged solutes typically have solvation shells that are significantly enriched in one of the ionic components, while the neutral solutes possess no such preference. The structurally ordered charged solutes are confined in solvation cages where they undergo in-cage vibrational motions, which persist for long times in the case of the smallest solutes. Likewise, these charged probes have the longest residence times, as a result of the strong attractions between the solute and solvent. Finally, we show that diffusion coefficients are simply related to residence times via a power law relationship. Through this work, we establish that the local ordering plays a pivotal role in slowing diffusion of ionic solutes.

Download or read book Ionic Liquids UnCOILed written by Kenneth R. Seddon and published by John Wiley & Sons. This book was released on 2012-10-26 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ionic Liquids UnCOILed presents decisively important reviews on new processes and recent developments in ionic liquid technology with an emphasis on commercial applications in which ionic liquids are replacing, or may replace, processes currently using conventional solvents. Ranging from applied to theoretical, synthetic to analytical, and biotechnological to electrochemical, the book features eleven chapters written by an international group of key academic and industrial chemists, exercising the judicious evaluation which they are uniquely qualified to do. This book is a must for R&D chemists in industrial, governmental and academic laboratories, and for commercial developers of environmentally-friendly, sustainable processes.

Download or read book Nanomaterials in Advanced Batteries and Supercapacitors written by Kenneth I. Ozoemena and published by Springer. This book was released on 2016-07-18 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an authoritative source of information on the use of nanomaterials to enhance the performance of existing electrochemical energy storage systems and the manners in which new such systems are being made possible. The book covers the state of the art of the design, preparation, and engineering of nanoscale functional materials as effective catalysts and as electrodes for electrochemical energy storage and mechanistic investigation of electrode reactions. It also provides perspectives and challenges for future research. A related book by the same editors is: Nanomaterials for Fuel Cell Catalysis.