Annealing Induced Crystallization and Characterization of Lithium Iron Silicate Cathode Materials PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Annealing Induced Crystallization and Characterization of Lithium Iron Silicate Cathode Materials PDF full book. Access full book title Annealing Induced Crystallization and Characterization of Lithium Iron Silicate Cathode Materials by Huijing Wei. Download full books in PDF and EPUB format.
Author: Huijing Wei
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"Lithium metal orthosilicates (Li2MSiO4) are attracting attention as one of the next generation cathode materials for automotive lithium-ion batteries (LIBs). In this thesis, lithium iron silicate (Li2FeSiO4, or LFS) crystals were successfully synthesized using a two-step method involving organic-assisted hydrothermal precipitation of an intermediate and annealing in reducing (5% H2) atmosphere. The hydrothermal synthesis step was conducted in the presence of organic additives, namely ethylenediamine (EN) and ethylene glycol (EG) that are known crystal growth control agents. The annealing-induced crystallization and structural transformation of the hydrothermally obtained intermediate into monoclinic and/or orthorhombic LFS phases was studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that LFS annealed at 400°C exhibits monoclinic nanocrystalline (10-20 nm size) structure whereas annealing at 900°C produces dense orthorhombic phase crystals (500 nm). Intermediate temperature annealing leads to mixed phase LFS. During annealing the organic components were found to decompose forming a carbon coating as determined by surface-sensitive Raman spectroscopy and X-ray photoelectron spectroscopy (XPS)." --
Author: Huijing Wei
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"Lithium metal orthosilicates (Li2MSiO4) are attracting attention as one of the next generation cathode materials for automotive lithium-ion batteries (LIBs). In this thesis, lithium iron silicate (Li2FeSiO4, or LFS) crystals were successfully synthesized using a two-step method involving organic-assisted hydrothermal precipitation of an intermediate and annealing in reducing (5% H2) atmosphere. The hydrothermal synthesis step was conducted in the presence of organic additives, namely ethylenediamine (EN) and ethylene glycol (EG) that are known crystal growth control agents. The annealing-induced crystallization and structural transformation of the hydrothermally obtained intermediate into monoclinic and/or orthorhombic LFS phases was studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that LFS annealed at 400°C exhibits monoclinic nanocrystalline (10-20 nm size) structure whereas annealing at 900°C produces dense orthorhombic phase crystals (500 nm). Intermediate temperature annealing leads to mixed phase LFS. During annealing the organic components were found to decompose forming a carbon coating as determined by surface-sensitive Raman spectroscopy and X-ray photoelectron spectroscopy (XPS)." --
Author: Huijing Wei
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
"Lithium metal silicates, have been proposed as potential candidates for lithium-ion battery cathode applications during the past decade. In this thesis, mesoporous nanostructured lithium iron silicate and mixed iron-manganese silicate and materials were successfully synthesized via a novel two-step synthesis method using organic-assisted hydrothermal precipitation and reductive annealing and afterwards were electrochemically evaluated. In a departure from previous LFS synthesis works, ferric iron salt is used in place of ferrous salt as an iron precursor source in the present work to provide unexplored crystallization pathways to sustainable cathode material production. The first hydrothermal step involves the formation of a poorly-crystalline reaction intermediate of ferric silicate starting from the concentrated ferric precursor solution (1 M). In the second reductive annealing step, the reaction intermediate transforms into crystalline LFS yielding two different nanostructured products at 400°C and 700°C retained for electrochemical evaluation. It is demonstrated that the formation of LFS from Fe(III) precursor is made possible by the action of ethylenediamine. Obtained LFS particles are found to be predominantly monoclinic and bear an in situ formed via organic decomposition N-doped carbon coating layer. Initial galvanostatic cycling indicates that the annealing temperature of LFS formation influences the Li-ion storage profile as it shifts from two-phase reaction in ball-milled LFS700 sample to solid solution reaction type in nanograined LFS400 sample. Stable charging and discharging capacity equivalent to one Li ion intercalation were reached for the first three cycles at various cycling rates. To study the long-term electrochemical response and structural evolution, the ball-milled LFS700 material was subjected to extended period of galvanostatic cycling tests at different cycling rates at 45°C and the structure of the cycled LFS was analyzed using high-energy synchrotron X-ray diffraction analysis. It is demonstrated that the LFS material undergoes a partial oxidation reaction induced by the electrolyte that leads to an irreversible formation of partially delithiated monoclinic LFS phase containing a fraction of ferric species. With the progression of cycling a complex structural evolution was observed to occur manifested as a combination of irreversible crystal transformation of monoclinic Li2FeIISiO4 to monoclinic LiFeIIISiO4 (inert to further intercalation) and simultaneous introduction of crystal disordering. The kinetics of these structural transformations are dependent on the applied cycling rates, with slower rates promoting the irreversible formation of the monoclinic LiFeIIISiO4 phase. By contrast the induced crystal disordering is believed to have a beneficial effect to overall capacity retention of the LFS700 cathode as no significant capacity fading was observed after 30 days.Mixed lithium iron manganese silicates were also prepared using the same synthesis method but replacing part of ferric salt precursor with manganese salt in various ratios in a preliminary effort to evaluate the effect of Mn on capacity attainment and charge compensation. The equimolar Li2Fe0.5Mn0.5SiO4 obtained at 700°C was subjected to 1.5 galvanostatic cycles using post-mortem and in situ synchrotron X-ray analyses to probe the type of structural and redox state changes occurring during the formation cycle. The LFMS material registered 1.5 Li exchange during the first charge which however was found to be followed by severe irreversible loss during discharge accompanied by significant degree of structure disordering. While charge compensation via metal redox activity involving Fe2+/Fe3+ and Mn2+/Mn3+ accounting for 1 Li exchange was confirmed, questions remain if the Mn3+/Mn4+ couple in LFMS could indeed enable attainment of reversible capacity beyond 1 Li"--
Author: Christian Dippel
Publisher:
ISBN:
Category :
Languages : en
Pages : 260
Get Book Here
Book Description
Author: Pengda Hong
Publisher:
ISBN: 9781361298015
Category :
Languages : en
Pages :
Get Book Here
Book Description
This dissertation, "Synthesis and characterization of LiNi0.6Mn0.35Co0.05O2 and Li2FeSiO4/C as electrodes for rechargeable lithium ion battery" by Pengda, Hong, 洪鹏达, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The rechargeable lithium ion batteries (LIB) are playing increasingly important roles in powering portal commercial electronic devices. They are also the potential power sources of electric mobile vehicles. The first kind of the cathode materials, LiXCoO2, was commercialized by Sony Company in 1980s, and it is still widely used today in LIB. However, the high cost of cobalt source, its environmental unfriendliness and the safety issue of LiXCoO2 have hindered its widespread usage today. Searching for alternative cathode materials with low cost of the precursors, being environmentally benign and more stable in usage has become a hot topic in LIB research and development. In the first part of this study, lithium nickel manganese cobalt oxide (LiNi0.6Mn0.35Co0.05O2) is studied as the electrode. The materials are synthesized at high temperatures by solid state reaction method. The effect of synthesis temperature on the electrochemical performance is investigated, where characterizations by, for example, X-ray diffraction (XRD) and scanning electron microscopy (SEM), for particle size distribution, specific surface area, and charge-discharge property, are done over samples prepared at different conditions for comparison. The electrochemical tests of the rechargeable Li ion batteries using LiNi0.6Mn0.35Co0.05 cathode prepared at optimum conditions are carried out in various voltage ranges, at different discharge rates and at high temperature. In another set of experiments, the material is adopted as anode with lithium foil as the cathode, and its capacitance is tested. In the second part of this study, the iron based cathode material is investigated. Lithium iron orthosilicate with carbon coating is synthesized at 700℃ by solid state reaction, which is assisted by high energy ball milling. Characterizations are done for discharge capacities of the samples with different carbon weight ratio coatings. DOI: 10.5353/th_b4715029 Subjects: Lithium ion batteries Cathodes Lithium compounds - Synthesis Cobalt compounds - Synthesis Manganese compounds - Synthesis Silicon compounds - Synthesis Iron compounds - Synthesis
Author: Jingsi Yang
Publisher:
ISBN:
Category : Lithium cells
Languages : en
Pages : 316
Get Book Here
Book Description
Author: Zumin Wang
Publisher: CRC Press
ISBN: 9814463418
Category : Science
Languages : en
Pages : 317
Get Book Here
Book Description
Crystalline semiconductors in the form of thin films are crucial materials for many modern, advanced technologies in fields such as microelectronics, optoelectronics, display technology, and photovoltaic technology. Crystalline semiconductors can be produced at surprisingly low temperatures (as low as 120C) by crystallization of amorphous semicon
Author: Suresh C. Pillai
Publisher: Springer
ISBN: 3319501445
Category : Technology & Engineering
Languages : en
Pages : 323
Get Book Here
Book Description
This volume provides expert coverage of the state-of-the-art in sol-gel materials for functional applications in energy, environment and electronics. The use of sol-gel technology has become a hotbed for cutting edge developments in many fields due to the accessibility of advanced materials through low energy processes. The book offers a broad view of this growing research area from basic science through high-level applications with the potential for commercialization and industrial use. Taking an integrated approach, expert chapters present a wide range of topics, from photocatalysts, solar cells and optics, to thin films and materials for energy storage and conversion, demonstrating the combined use of chemistry, physics, materials science and engineering in the search for solutions to some of the most challenging problems of our time.
Author: Gholam-Abbas Nazri
Publisher: Springer Science & Business Media
ISBN: 0387926747
Category : Science
Languages : en
Pages : 725
Get Book Here
Book Description
Lithium Batteries: Science and Technology is an up-to-date and comprehensive compendium on advanced power sources and energy related topics. Each chapter is a detailed and thorough treatment of its subject. The volume includes several tutorials and contributes to an understanding of the many fields that impact the development of lithium batteries. Recent advances on various components are included and numerous examples of innovation are presented. Extensive references are given at the end of each chapter. All contributors are internationally recognized experts in their respective specialty. The fundamental knowledge necessary for designing new battery materials with desired physical and chemical properties including structural, electronic and reactivity are discussed. The molecular engineering of battery materials is treated by the most advanced theoretical and experimental methods.
Author: Lide M Rodriguez-Martinez
Publisher: William Andrew
ISBN: 0323429963
Category : Technology & Engineering
Languages : en
Pages : 348
Get Book Here
Book Description
Emerging Nanotechnologies in Rechargeable Energy Storage Systems addresses the technical state-of-the-art of nanotechnology for rechargeable energy storage systems. Materials characterization and device-modeling aspects are covered in detail, with additional sections devoted to the application of nanotechnology in batteries for electrical vehicles. In the later part of the book, safety and regulatory issues are thoroughly discussed. Users will find a valuable source of information on the latest developments in nanotechnology in rechargeable energy storage systems. This book will be of great use to researchers and graduate students in the fields of nanotechnology, electrical energy storage, and those interested in materials and electrochemical cell development. - Gives readers working in the rechargeable energy storage sector a greater awareness on how novel nanotechnology oriented methods can help them develop higher-performance batteries and supercapacitor systems - Provides focused coverage of the development, process, characterization techniques, modeling, safety and applications of nanomaterials for rechargeable energy storage systems - Presents readers with an informed choice in materials selection for rechargeable energy storage devices
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1068
Get Book Here
Book Description
