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Nguyen, Hanh D. "Structural Elucidation of tert-Butyllithium/Lithium Alkoxide and Lithium Hydride/Lithium Alkoxide Mixed Aggregates". Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278525/.
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The effects of lithium alkoxides on the rates of reactions and on the structures of a series of tert-butyllithium/lithium alkoxide mixed aggregates were studied, where the alkoxides were iso-butoxide, tert-butoxide and menthoxide. It was found that their effects depend not only on their amount present, but also on their steric bulk.
The tert-butyllithium/lithium alkoxide mixed aggregates were exposed to UV light or heat to form lithium hydride/lithium alkoxide mixed aggregates. The aggregation states were assigned from either 13C-6Li coupling or a new technique based on the relative intensity of NMR peaks using different nuclei. The compounds formed depend upon the method of formation and the alkoxide. The unique properties of the lithium hydride/lithium alkoxide mixed aggregates are their high solubility in hydrocarbon solutions, very reactive bases, showing 6Li-1H couplings, and having only one hydride ion per aggregate. Their formation, reactivity, solubility, and aggregation states were found to depend on the size of lithium alkoxides. X-ray crystal structures of lithium tert-butoxide and lithium menthoxide were also studied and found to be hexameric.
2
Aojula, Kuldip Singh. "Electrodeposition of lithium from dimethylsulphoxide/lithium chloride medium". Thesis, University of Southampton, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305484.
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Harrison, Hollie. "The electrodialysis of lithium sulphate to lithium hydroxide". Thesis, Harrison, Hollie (2018) The electrodialysis of lithium sulphate to lithium hydroxide. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/40456/.
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There is currently an increasing demand for lithium-ion batteries, and therefore a push within the industry to produce lithium hydroxide. Electrodialysis has been shown to be a promising new technology for producing lithium hydroxide.
A three-compartment batch electrodialysis cell was constructed, utilising an anionic exchange membrane and a cationic exchange membrane. This cell was constructed in order to produce lithium hydroxide from lithium sulphate salt. The cell was run under multiple different conditions to observe the effect that they would have on the recovery of lithium within the lithium hydroxide of the catholyte compartment within the cell. The initial pH of the solution, the temperature of the system, the initial concentration of lithium sulphate and the residence time within the cell were all tested in separate experiments in order to observe how they would influence the system and the production of lithium hydroxide.
The results of this study indicated that by decreasing the initial concentration of the lithium sulphate within the cell, the lithium recovery is dramatically increased, at 30 wt.% lithium sulphate, 18.3% of the lithium is recovered within 4 hours into the catholyte solution as lithium hydroxide. At 5 wt.% lithium sulphate, 81.2% of the lithium is recovered within 4 hours into the catholyte as lithium hydroxide.
The results also suggest, the rate of production of lithium hydroxide is fastest when the residence time within the cell is reduced, however, a longer residence time within the cell will increase the lithium recovery. A 4-hour test at 30 wt.% of lithium sulphate yielded a 23.1% lithium recovery within the catholyte solution. When this residence time was doubled, the recovery was increased to 37% lithium within the catholyte as lithium hydroxide.
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Chinyama, Luzendu Gabriel. "Recovery of Lithium from Spent Lithium Ion Batteries". Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-59866.
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Batteries have found wide use in many household and industrial applications and since the 1990s, they have continued to rapidly shape the economy and social landscape of humans. Lithium ion batteries, a type of rechargeable batteries, have experienced a leap-frog development at technology and market share due to their prominent performance and environmental advantages and therefore, different forecasts have been made on the future trend for the lithium ion batteries in-terms of their use. The steady growth of energy demand for consumer electronics (CE) and electric vehicles (EV) have resulted in the increase of battery consumption and the electric vehicle (EV) market is the most promising market as it will consume a large amount of the lithium ion batteries and research in this area has reached advanced stages. This will consequently be resulting in an increase of metal-containing hazardous waste. Thus, to help prevent environmental and raw materials consumption, the recycling and recovery of the major valuable components of the spent lithium ion batteries appears to be beneficial. In this thesis, it was attempted to recover lithium from a synthetic slag produced using pyrometallurgy processing and later treated using hydrometallurgy. The entire work was done in the laboratory to mimic a base metal smelting slag. The samples used were smelted in a Tamman furnace under inert atmosphere until 1250oC was reached and then maintained at this temperature for two hours. The furnace was then switched off to cool for four hours and the temperature gradient during cooling was from 1250oC to 50oC. Lime was added as one of the sample materials to change the properties of the slag and eventually ease the possibility of selectively leaching lithium from the slag. It was observed after smelting that the slag samples had a colour ranging from dark grey to whitish grey among the samples.The X - ray diffractions done on the slag samples revealed that the main phases identified included fayalite (Fe2SiO4), magnetite (Fe3O4), ferrobustamine (CaFeO6Si2), Kilchoanite (Ca3Si2O7), iron oxide (Fe0.974O) and quartz (SiO2). The addition of lime created new compound in the slag with the calcium replacing the iron. The new phases formed included hedenbergite (Ca0.5Fe1.5Si2O6), ferrobustamine (CaFeO6Si2), Kilchoanite (Ca3Si2O7) while the addition of lithium carbonate created lithium iron (II) silicate (FeLi2O4Si) and dilithium iron silicate (FeLi2O4Si) phases.The Scanning Electron Microscopy (SEM) micrographs of the slag consisted mainly of Fe, Si and O while the Ca was minor. Elemental compositions obtained after analysis was used to identify the different phases in all the slag samples. The main phases identified were the same as those identified by the XRD analysis above except no phase with lithium was identified. No lithium was detected by SEM due to the design of the equipment as it uses beryllium planchets which prevent the detection of lithium.Leaching experiments were done on three slag samples (4, 5 and 6) that had lithium carbonate additions. Leaching was done for four hours using water, 1 molar HCl and 1 molar H2SO4 as leaching reagents at room temperature. Mixing was done using a magnetic stirrer. The recoveries obtained after leaching with water gave a lithium recovery of 0.4%. Leaching with HCl gave a recovery of 8.3% while a recovery of 9.4% was obtained after leaching with H2SO4.It can be concluded that the percentage of lithium recovered in this study was very low and therefore it would not be economically feasible. It can also be said that the recovery of lithium from the slag system studied in this work is very difficult because of the low recoveries obtained. It is recommended that test works be done on spent lithium ion batteries so as to get a better understanding of the possibilities of lithium recovery as spent lithium ion batteries contain other compounds unlike the ones investigated in this study.
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Björkman, Carl Johan. "Detection of lithium plating in lithium-ion batteries". Thesis, KTH, Kemiteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266369.
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With an increasing demand for sustainable transport solutions, there is a demand for electrified vehicles. One way to store energy on board an electrified vehicle is to use a lithium-ion battery (LIB). This battery technology has many advantages, such as being rechargeable and enabling reasonably high power output and capacity. To ensure reliable operation of LIB:s, the battery management system (BMS) must be designed with regards to the electrochemical dynamics of the battery. However, since the battery ages over time, the dynamics changes as well. It is possible to predict ageing, but some ageing mechanisms can occur randomly, e.g. due to variations of circumstances during manufacturing, and variations of battery user choices. Hence, by monitoring ageing mechanisms in situ, the BMS can adapt accordingly, similar to a closed loop control system. One ageing mechanism in LIB:s is lithium plating. This mechanism signifies when Li ions are electrochemically deposited as metal onto the negative electrode of the LIB during charging, and can induce other ageing mechanisms, such as gassing or electrolyte reduction. The present project has investigated a method for detecting Li plating in situ after its occurrence by both analysing the voltage change over time during open-circuit voltage (OCV) periods after charging and monitoring battery swelling forces. Results show a correlation between a high probability of Li plating and the appearance of a swelling force peak and an OCV plateau. However, results also show a possible correlation between the onset of Li plating and the onset of the swelling force peak, while also showing a greater detectability of the force signal compared to the electrochemical signal. Furthermore, the present results show that the magnitudes of both signals are probably related to the amount of plated Li. The amount of irreversibly lost Li from plating is shown to have a possible correlation with accumulation of swelling pressure. However, to further validate the feasibility of these two signals, more advanced analysis is required, which was not available during this project.Med en ökande efterfråga på hållbara transportlösningar så finns det ett behov av elektrifierade fordon. Ett sätt att lagra energi ombord ett elektrifierat fordon är att använda et litium-jon-batteri. Denna batteriteknologi har många fördelar: t.ex. är dessa batterier återladdningsbara, och de kan leverera höga uteffekter samtidigt som de kan ha ett stort energiinnehåll. för att säkerställa en säker drift av litium-jon-batterier måste batteriets styrsystem vara designat med hänsyn till den elektrokemiska dynamiken inuti batteriet. Dock åldras batteriet med tiden, vilket innebär att denna dynamik ändras med tiden, vilket innebär att styrningen av batteriet måste anpassa sig till denna föråldring. Det är möjligt att förutspå åldring av batterier, men vissa åldringsmekanismer kan ske slumpartat, t.ex. via slumpmässiga förändringar i tillverkningsprocessen av batteriet, eller variationer i användningen av batteriet. Genom att därmed bevaka dessa åldringsmekanismer in situ så kan styrsystemets algoritm anpassa sig utmed batteriåldringen, trots dessa slumpartade effekter. En åldringmekanism hos litium-jon-batterier är s.k. litiumplätering. Denna mekanism innebär att litium-joner elektrokemiskt pläteras i form av metalliskt litium på ytan av litium-jon-batteriets negativa elektrod. Mekanismen kan också inducera andra åldringsmekanismer, t.ex. gasutveckling eller elektrolytreduktion. Detta projekt har undersökt en metod för att detektera litiumplätering in situ efter att plätering har skett, genom att både analysera öppencellspänningens (OCV) förändring med tiden direkt efter uppladdning samt analysera de svällande krafterna som uppstår under uppladdning av batteriet. Resultaten visar på en korrelation mellan en hög sannolikhet för litiumplätering och observationen av en topp i svällningskraft och en platå i OCV-kurvan. resultaten visar också en möjlig korrelation mellan påbörjandet av litium-plätering och påbörjandet av toppen i svällningskraft. Vidare visar även resultaten ett troligt samband mellan signalernas magnitud och mängden pläterat litium. Slutligen visar resultaten också ett möjligt samband mellan irreversibelt pläterat litium och ett svällningstryck som ackumuleras med varje uppladdningscykel. Dock krävs det en validering med mer avancerade analysmetoder för att säkerställa användningsbarheten av dessa två signaler, vilket ej var möjligt inom detta projekt.
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Harvey, Norman Stewart. "Lithium treatment". Thesis, University of Sheffield, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321423.
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Myalo, Zolani. "Graphenised Lithium Iron Phosphate and Lithium Manganese Silicate Hybrid Cathode Systems for Lithium-Ion Batteries". University of the Western Cape, 2017. http://hdl.handle.net/11394/6036.
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Magister Scientiae - MSc (Chemistry)This research was based on the development and characterization of graphenised lithium iron phosphate-lithium manganese silicate (LiFePO4-Li2MnSiO4) hybrid cathode materials for use in Li-ion batteries. Although previous studies have mainly focused on the use of a single cathode material, recent works have shown that a combination of two or more cathode materials provides better performances compared to a single cathode material. The LiFePO4- Li2MnSiO4 hybrid cathode material is composed of LiFePO4 and Li2MnSiO4. The Li2MnSiO4 contributes its high working voltage ranging from 4.1 to 4.4 V and a specific capacity of 330 mA h g-1, which is twice that of the LiFePO4 which, in turn, offers its long cycle life, high rate capacity as well as good electrochemical and thermal stability. The two cathode materials complement each other's properties however they suffer from low electronic conductivities which were suppressed by coating the hybrid material with graphene nanosheets. The synthetic route entailed a separate preparation of the individual pristine cathode materials, using a sol-gel protocol. Then, the graphenised LiFePO4-Li2MnSiO4 and LiFePO4-Li2MnSiO4 hybrid cathodes were obtained in two ways: the hand milling (HM) method where the pristine cathodes were separately prepared and then mixed with graphene using a pestle and mortar, and the in situ sol-gel (SG) approach where the Li2MnSiO4 and graphene were added into the LiFePO4 sol, stirred and calcined together.
2021-04-30
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Popovic, Jelena. "Novel lithium iron phosphate materials for lithium-ion batteries". Phd thesis, Universität Potsdam, 2011. http://opus.kobv.de/ubp/volltexte/2011/5459/.
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Conventional energy sources are diminishing and non-renewable, take million years to form and cause environmental degradation. In the 21st century, we have to aim at achieving sustainable, environmentally friendly and cheap energy supply by employing renewable energy technologies associated with portable energy storage devices. Lithium-ion batteries can repeatedly generate clean energy from stored materials and convert reversely electric into chemical energy. The performance of lithium-ion batteries depends intimately on the properties of their materials. Presently used battery electrodes are expensive to be produced; they offer limited energy storage possibility and are unsafe to be used in larger dimensions restraining the diversity of application, especially in hybrid electric vehicles (HEVs) and electric vehicles (EVs).
This thesis presents a major progress in the development of LiFePO4 as a cathode material for lithium-ion batteries. Using simple procedure, a completely novel morphology has been synthesized (mesocrystals of LiFePO4) and excellent electrochemical behavior was recorded (nanostructured LiFePO4). The newly developed reactions for synthesis of LiFePO4 are single-step processes and are taking place in an autoclave at significantly lower temperature (200 deg. C) compared to the conventional solid-state method (multi-step and up to 800 deg. C). The use of inexpensive environmentally benign precursors offers a green manufacturing approach for a large scale production. These newly developed experimental procedures can also be extended to other phospho-olivine materials, such as LiCoPO4 and LiMnPO4. The material with the best electrochemical behavior (nanostructured LiFePO4 with carbon coating) was able to delive a stable 94% of the theoretically known capacity.Konventionelle Energiequellen sind weder nachwachsend und daher nachhaltig nutzbar, noch weiterhin langfristig verfügbar. Sie benötigen Millionen von Jahren um gebildet zu werden und verursachen in ihrer Nutzung negative Umwelteinflüsse wie starke Treibhausgasemissionen. Im 21sten Jahrhundert ist es unser Ziel nachhaltige und umweltfreundliche, sowie möglichst preisgünstige Energiequellen zu erschließen und nutzen. Neuartige Technologien assoziiert mit transportablen Energiespeichersystemen spielen dabei in unserer mobilen Welt eine große Rolle. Li-Ionen Batterien sind in der Lage wiederholt Energie aus entsprechenden Prozessen nutzbar zu machen, indem sie reversibel chemische in elektrische Energie umwandeln. Die Leistung von Li-Ionen Batterien hängen sehr stark von den verwendeten Funktionsmaterialien ab. Aktuell verwendete Elektrodenmaterialien haben hohe Produktionskosten, verfügen über limitierte Energiespeichekapazitäten und sind teilweise gefährlich in der Nutzung für größere Bauteile. Dies beschränkt die Anwendungsmöglichkeiten der Technologie insbesondere im Gebiet der hybriden Fahrzeugantriebe. Die vorliegende Dissertation beschreibt bedeutende Fortschritte in der Entwicklung von LiFePO4 als Kathodenmaterial für Li-Ionen Batterien. Mithilfe einfacher Syntheseprozeduren konnten eine vollkommen neue Morphologie (mesokristallines LiFePo4) sowie ein nanostrukturiertes Material mit exzellenten elektrochemischen Eigenschaften hergestellt werden. Die neu entwickelten Verfahren zur Synthese von LiFePo4 sind einschrittig und bei signifikant niedrigeren Temperaturen im Vergleich zu konventionellen Methoden. Die Verwendung von preisgünstigen und umweltfreundlichen Ausgangsstoffen stellt einen grünen Herstellungsweg für die large scale Synthese dar. Mittels des neuen Synthesekonzepts konnte meso- und nanostrukturiertes LiFe PO4 generiert werden. Die Methode ist allerdings auch auf andere phospho-olivin Materialien (LiCoPO4, LiMnPO4) anwendbar. Batterietests der besten Materialien (nanostrukturiertes LiFePO4 mit Kohlenstoffnanobeschichtung) ergeben eine mögliche Energiespeicherung von 94%.
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Cvitaš, Marko Tomislav. "Interactions and collisions of cold molecules : lithium + lithium dimer". Thesis, Durham University, 2004. http://etheses.dur.ac.uk/3667/.
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There is at present great interest in the properties of ultracold molecules. Molecules are created in traps in excited rovibrational states and any vibrational relaxation results in the trap loss. This thesis provides a theoretical study of interactions and collisions in the spin-polarized lithium -b lithium dimer system at ultralow energies. Potential energy surface of the electronic quartet ground state of lithium trimer is generated ab initio using the CCSD(T) method and represented by an IMLS/Shepard fit. Long-range nonadditive interactions are modelled using a symmetric global form with coefficients taken from a fit to the atom-molecule dispersion coefficients. The surface allows barrierless atom-exchange reactions. It has a global minimum of ≈ 4000 cm(^-1) at equilateral geometries with r(_e) = 3.1 Å. The nonadditive interactions are very strong near equilibrium. They increase the well depth by a factor of 4 and reduce the interatomic distance by ≈ 1 Å. Another surface of À symmetry in C(_s) meets the ground state surface at linear geometries at short range. Part of the seam, near D(_ooh) geometries, is in an energetically accessible region for cold collisions. Inside the seam, the lowest À surface correlates with (^4)II rather than (^4)Σ state. Inelastic and reactive collisions are investigated using a quantum mechanical coupled channel method in hyperspherical coordinates. Bosonic and fermionic systems in the spin-stretched states are considered. The inelastic rate coefficients from the rovibrationally excited states of dimer at ultralow collision energies are large, often above 10-(^-10) cm(^3)s(^-1) The elastic cross sections are ≈ 3 orders of magnitude lower at 1 nK. Atom-molecule mixtures, at the densities found in Bose-Einstein condensates of alkali metal atoms that were recently produced, would last only a fraction of a second. Classical Langevin model describes semi-quantitatively the energy dependence of inelastic cross sections above ≈ 50 mK. No systematic differences between the bosonic and fermionic systems were found. Sensitivity of the results on potential was investigated. Reactions in isotopic mixtures of lithium may be exothermic even from the molecular ground state. The reactive rate coefficients are 1 - 2 orders of magnitude smaller than those in systems involving an initially vibrationally excited dimer.
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Roß, Sebastian [Verfasser]. "Lithium conductivity characteristics of amorphous lithium silicate and lithium alumosilicate materials and their compaction / Sebastian Roß". Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2015. http://d-nb.info/1068347899/34.
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Park, Bongjin. "Single electron transfer in reactions involving alkyl halides with lithium alkylamide, lithium alkyl and lithium metal". Diss., Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/27052.
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Taubert, Franziska. "Thermodynamische Untersuchungen in den Systemen Lithium-Silicium und Lithium-Zinn". Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2017. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-229567.
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Lithium-Ionen-Batterien besitzen ein ausgezeichnetes Potential für die Energiespeicherung. Das derzeit dominierende Anodenmaterial in Lithium-Ionen-Batterien mit einer Energiespeicherkapazität von 339 mAh/g ist Graphit. Als Alternative hierfür bieten sich Lithiumsilicide und Lithiumstannide an. Diese Materialien zeichnen sich durch eine viel größere Speicherkapazität und geringere Selbstentladungspotentiale aus. Für die kommerzielle Anwendung dieser beiden Systeme in Lithium-Ionen-Batterien werden grundlegende und verlässliche thermodynamische Daten benötigt.
Derzeit ist die Existenz von sieben Lithiumsiliciden sicher nachgewiesen. Dazu zählen die sechs stabilen Phasen Li17Si4, Li16.42Si4, Li13Si4, Li7Si3, Li12Si7, die Hochdruckphase LiSi und die metastabile Phase Li15Si4. Für die ersten fünf genannten Phasen wurden in der ersten Förderperiode des Schwerpunktprogrammes 1473 Wärmekapazitäten und Standardentropien bestimmt. Bei den Lithiumstanniden sind derzeit sieben Phasen gesichert belegt. Allerdings existiert für keine Phase der Lithiumstannide ein verlässlicher thermodynamischer Basisdatensatz. Aus diesem Grund wurden für die beiden zuletzt genannten Lithiumsilicide (Li15Si4 und LiSi), sowie für die Lithiumstannide Li17Sn4, Li7Sn2, Li13Sn5 und Li7Sn3 die fehlenden thermodynamischen Daten experimentell bestimmt.
Die hergestellten Phasen wurden zunächst mittels Röntgenbeugung, thermischer und chemischer Analyse charakterisiert. Ein Schwerpunkt dieser Arbeit lag auf der experimentellen Bestimmung der Wärmekapazitäten in einem Temperaturbereich von 2 K bis zur jeweiligen Zersetzungstemperatur der untersuchten Verbindungen. Hierfür wurden zwei unterschiedliche Kalorimeter verwendet: ein Physical Property Measurement System (Quantum Design) von 2 K bis 300 K und eine DSC 111 (Setaram), beginnend ab 300 K. Die experimentellen Daten konnten mit Messunsicherheiten von 1 % bis 2 % über 20 K und bis zu 20 % unterhalb von 20 K angegeben werden. Die Messungen bei niedrigen Temperaturen erlauben zudem die Berechnung der Standardentropien, sowie die Bestimmung von elektronischen Beiträgen und Gitterschwingungsbeiträgen zur Wärmekapazität. Weiterhin ist Fokus dieser Arbeit die Bestimmung der Standardbildungsenthalpien der Lithiumsilicide und Lithiumstannide auf Basis von Wasserstoffsorptionsmessungen mittels einer Sieverts-Apparatur. Hierfür wurden erstmals Messungen an den Lithiumsiliciden ausgehend von Li17Si4, LiH:Si (Li:Si = 17:4), Li16.42Si4 und LiSi durchgeführt. Für die Lithiumstannide dienten als Ausgangsmaterial Li17Sn4, LiH:Sn (Li:Sn =17:4), sowie Li7Sn2 und LiH:Sn (Li:Sn = 7:2). Die Anwendung des van´t-Hoff-Plots resultierte in Messunsicherheiten von mindestens 10 %. Aus diesem Grund wurde eine alternative Auswertemethode gewählt, bei der die ermittelten Wärmekapazitäten und Standardentropien mit den Gleichgewichtsdrücken aus den Wasserstoffsorptionsmessungen miteinander verknüpft werden. Auf diese Weise konnten Standardbildungsenthalpien für die untersuchten Phasen mit Fehlern kleiner 1 % ermittelt werden. Aus den Ergebnissen dieser Arbeit resultierte ein vollständiger, gesicherter thermodynamischer Datensatz für das System Li-Si. Das berechnete Li-Si-Phasendiagramm ist im sehr guten Einklang mit experimentellen literaturbekannten Daten. Für die Lithiumstannide erfolgte eine Validierung der ermittelten thermodynamischen Werte.
Die in dieser Arbeit erzielten Ergebnisse liefern einen wesentlichen Beitrag zur Verbesserung der Datenbasis für thermodynamische Berechnungen und für das Verständnis von Phasensequenzen und Gleichgewichten beim Einsatz von Lithiumsiliciden bzw. Lithiumstanniden als Anodenmaterialien in Lithium-Ionen-Batterien.
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Almohareb, Muneerah. "Novel Lithium Ionic Conducting Perovskite Materials for Lithium-Air Batteries". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36515.
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Lithium Air (Li/O2) batteries are energy conversion devices that produce electricity from the oxidation of lithium metal at the anode and the reduction of molecular oxygen at the cathode. These batteries are considered as promising rechargeable cells for high power applications due to their high power density ranging from 1000 to 2000 Wh/kg. However, one of the most significant challenges is the need to separate the metallic lithium anode from any oxygen or water-containing environment while at the same time allowing fast and efficient lithium ion transport through the electrolyte. Therefore, lithium ion conducting materials that are water and CO2 resistant are a prerequisite.
Common materials used as anode protective films and/or Li+ conducting electrolytes for lithium air batteries are perovskite-type oxides (formula: ABO3). Perovskites are good candidates for this application because of their versatility, particularly in regards to ionic conductivity. In the present work, a low cost perovskite family such as SFO (SmFeO3) is developed as a lithium ion conducting material by the introduction of Li+ into its lattice.
The perovskites have been synthesized using a solid-state reaction method (SSR) and characterized using different techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDS) and electrochemical impedance spectroscopy (EIS). The synthesized perovskites are based on samarium lithium ferrite and divided into two groups depending on the formal presence of vacancies in the stoichiometric formula. The first group (SLFO) with no formal vacancies has the stoichiometric formula of SmxLi1-xFeO2+x (where x = 0.1, 0.2, 0.3, 0.5 and 0.7). While the second group (SLFO*) was generated with less metal atoms than specified in the perovskite structure, thereby generating a structure with intrinsic vacancies and with the formula, Sm(x)Li([1-x] – [0.1] or [0.2]) FeO3-δ (where x = 0.3, 0.4, 0.5 and 0.6). Finally, the effect of varying Li and Sm concentrations in both groups and vacancies created in the lattice for the second group, on the ionic conductivity is explored.
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Best, Adam Samuel 1976. "Lithium-ion conducting electrolytes for use in lithium battery applications". Monash University, School of Physics and Materials Engineering, 2001. http://arrow.monash.edu.au/hdl/1959.1/9240.
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Li, Juchuan. "UNDERSTANDING DEGRADATION AND LITHIUM DIFFUSION IN LITHIUM ION BATTERY ELECTRODES". UKnowledge, 2012. http://uknowledge.uky.edu/cme_etds/12.
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Lithium-ion batteries with higher capacity and longer cycle life than that available today are required as secondary energy sources for a wide range of emerging applications. In particular, the cycling performance of several candidate materials for lithium-ion battery electrodes is insufficient because of the fast capacity fading and short cycle life, which is mainly a result of mechanical degradation.
This dissertation mainly focuses on the issue of mechanical degradation in advanced lithium-ion battery electrodes. Thin films of tin electrodes were studied where we observed whisker growth as a result of electrochemical cycling. These whiskers bring safety concerns because they may penetrate through the separator, and cause short-circuit of the electrochemical cells. Cracking patterns generated in amorphous silicon thin film electrodes because of electrochemical cycling were observed and analyzed. A two-dimensional spring-block model was proposed to successfully simulate the observed cracking patterns. With semi-quantitative study of the cracking pattern features, two strategies to void cracking in thin-film electrodes were proposed, namely reducing the film thickness and patterning the thin-film electrodes.
We also investigated electrodes consisting of low melting point elements and showed that cracks can be self-healed by the solid-to-liquid phase transformation upon cycling. Using gallium as an example, mechanical degradation as a failure mechanism for lithium-ion battery electrodes can be eliminated.
In order to quantitatively understand the effect of surface modification on electrodes, we analyzed diffusion equations with boundary conditions of finite interfacial reactions, and proposed a modified potentialstatic intermittent titration technique (PITT) as an electro-analytical technique to study diffusion and interfacial kinetics. The modified PITT has been extended to thin-film geometry and spherical geometry, and thus can be used to study thin-film and composite electrodes consisting of particles as active materials.
16
Hein, Smon [Verfasser]. "Modeling of lithium plating in lithium-ion-batteries / Smon Hein". Ulm : Universität Ulm, 2018. http://d-nb.info/1162539917/34.
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17
Lin, Jian. "Novel Lithium Salt and Polymer Electrolytes for Polymer Lithium Batteries". Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1215572988.
Pełny tekst źródła
18
Damen, Libero <1980>. "Advanced lithium and lithium-ion rechargeable batteries for automotive applications". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3427/1/Damen_Libero_Tesi.pdf.
Pełny tekst źródłaStreszczenie:
The worldwide demand for a clean and low-fuel-consuming transport promotes the
development of safe, high energy and power electrochemical storage and conversion
systems. Lithium-ion batteries (LIBs) are considered today the best technology for this
application as demonstrated by the recent interest of automotive industry in hybrid (HEV)
and electric vehicles (EV) based on LIBs. This thesis work, starting from the synthesis and
characterization of electrode materials and the use of non-conventional electrolytes,
demonstrates that LIBs with novel and safe electrolytes and electrode materials meet the
targets of specific energy and power established by U.S.A. Department of Energy (DOE)
for automotive application in HEV and EV.
In chapter 2 is reported the origin of all chemicals used, the description of the
instruments used for synthesis and chemical-physical characterizations, the electrodes
preparation, the batteries configuration and the electrochemical characterization procedure
of electrodes and batteries.
Since the electrolyte is the main critical point of a battery, in particular in large-
format modules, in chapter 3 we focused on the characterization of innovative and safe
electrolytes based on ionic liquids (characterized by high boiling/decomposition points,
thermal and electrochemical stability and appreciable conductivity) and mixtures of ionic
liquid with conventional electrolyte.
In chapter 4 is discussed the microwave accelerated sol–gel synthesis of the carbon-
coated lithium iron phosphate (LiFePO 4 -C), an excellent cathode material for LIBs thanks
to its intrinsic safety and tolerance to abusive conditions, which showed excellent
electrochemical performance in terms of specific capacity and stability.
In chapter 5 are presented the chemical-physical and electrochemical
characterizations of graphite and titanium-based anode materials in different electrolytes.
We also characterized a new anodic material, amorphous SnCo alloy, synthetized with a
nanowire morphology that showed to strongly enhance the electrochemical stability of the
material during galvanostatic full charge/discharge cycling.
Finally, in chapter 6, are reported different types of batteries, assembled using the
LiFePO 4 -C cathode material, different anode materials and electrolytes, characterized by
deep galvanostatic charge/discharge cycles at different C-rates and by test procedures of the DOE protocol for evaluating pulse power capability and available energy. First, we
tested a battery with the innovative cathode material LiFePO 4 -C and conventional graphite
anode and carbonate-based electrolyte (EC DMC LiPF 6 1M) that demonstrated to surpass
easily the target for power-assist HEV application. Given that the big concern of
conventional lithium-ion batteries is the flammability of highly volatile organic carbonate-
based electrolytes, we made safe batteries with electrolytes based on ionic liquid (IL). In
order to use graphite anode in IL electrolyte we added to the IL 10% w/w of vinylene
carbonate (VC) that produces a stable SEI (solid electrolyte interphase) and prevents the
graphite exfoliation phenomenon. Then we assembled batteries with LiFePO 4 -C cathode,
graphite anode and PYR 14 TFSI 0.4m LiTFSI with 10% w/w of VC that overcame the DOE
targets for HEV application and were stable for over 275 cycles. We also assembled and
characterized ―high safety‖ batteries with electrolytes based on pure IL, PYR 14 TFSI with
0.4m LiTFSI as lithium salt, and on mixture of this IL and standard electrolyte
(PYR 14 TFSI 50% w/w and EC DMC LiPF 6 50% w/w), using titanium-based anodes (TiO 2
and Li 4 Ti 5 O 12 ) that are commonly considered safer than graphite in abusive conditions.
The batteries bearing the pure ionic liquid did not satisfy the targets for HEV application,
but the batteries with Li 4 Ti 5 O 12 anode and 50-50 mixture electrolyte were able to surpass
the targets. We also assembled and characterized a lithium battery (with lithium metal
anode) with a polymeric electrolyte based on poly-ethilenoxide (PEO 20 –
LiCF 3 SO 3 +10%ZrO 2 ), which satisfied the targets for EV application and showed a very
impressive cycling stability.
In conclusion, we developed three lithium-ion batteries of different chemistries that
demonstrated to be suitable for application in power-assist hybrid vehicles: graphite/EC
DMC LiPF 6 /LiFePO 4 -C, graphite/PYR 14 TFSI 0.4m LiTFSI with 10% VC/LiFePO 4 -C and
Li 4 T i5 O 12 /PYR 14 TFSI 50%-EC DMC LiPF 6 50%/LiFePO 4 -C. We also demonstrated that
an all solid-state polymer lithium battery as Li/PEO 20 –LiCF 3 SO 3 +10%ZrO 2 /LiFePO 4 -C is
suitable for application on electric vehicles. Furthermore we developed a promising anodic
material alternative to the graphite, based on SnCo amorphous alloy.
19
Damen, Libero <1980>. "Advanced lithium and lithium-ion rechargeable batteries for automotive applications". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3427/.
Pełny tekst źródłaStreszczenie:
The worldwide demand for a clean and low-fuel-consuming transport promotes the
development of safe, high energy and power electrochemical storage and conversion
systems. Lithium-ion batteries (LIBs) are considered today the best technology for this
application as demonstrated by the recent interest of automotive industry in hybrid (HEV)
and electric vehicles (EV) based on LIBs. This thesis work, starting from the synthesis and
characterization of electrode materials and the use of non-conventional electrolytes,
demonstrates that LIBs with novel and safe electrolytes and electrode materials meet the
targets of specific energy and power established by U.S.A. Department of Energy (DOE)
for automotive application in HEV and EV.
In chapter 2 is reported the origin of all chemicals used, the description of the
instruments used for synthesis and chemical-physical characterizations, the electrodes
preparation, the batteries configuration and the electrochemical characterization procedure
of electrodes and batteries.
Since the electrolyte is the main critical point of a battery, in particular in large-
format modules, in chapter 3 we focused on the characterization of innovative and safe
electrolytes based on ionic liquids (characterized by high boiling/decomposition points,
thermal and electrochemical stability and appreciable conductivity) and mixtures of ionic
liquid with conventional electrolyte.
In chapter 4 is discussed the microwave accelerated sol–gel synthesis of the carbon-
coated lithium iron phosphate (LiFePO 4 -C), an excellent cathode material for LIBs thanks
to its intrinsic safety and tolerance to abusive conditions, which showed excellent
electrochemical performance in terms of specific capacity and stability.
In chapter 5 are presented the chemical-physical and electrochemical
characterizations of graphite and titanium-based anode materials in different electrolytes.
We also characterized a new anodic material, amorphous SnCo alloy, synthetized with a
nanowire morphology that showed to strongly enhance the electrochemical stability of the
material during galvanostatic full charge/discharge cycling.
Finally, in chapter 6, are reported different types of batteries, assembled using the
LiFePO 4 -C cathode material, different anode materials and electrolytes, characterized by
deep galvanostatic charge/discharge cycles at different C-rates and by test procedures of the DOE protocol for evaluating pulse power capability and available energy. First, we
tested a battery with the innovative cathode material LiFePO 4 -C and conventional graphite
anode and carbonate-based electrolyte (EC DMC LiPF 6 1M) that demonstrated to surpass
easily the target for power-assist HEV application. Given that the big concern of
conventional lithium-ion batteries is the flammability of highly volatile organic carbonate-
based electrolytes, we made safe batteries with electrolytes based on ionic liquid (IL). In
order to use graphite anode in IL electrolyte we added to the IL 10% w/w of vinylene
carbonate (VC) that produces a stable SEI (solid electrolyte interphase) and prevents the
graphite exfoliation phenomenon. Then we assembled batteries with LiFePO 4 -C cathode,
graphite anode and PYR 14 TFSI 0.4m LiTFSI with 10% w/w of VC that overcame the DOE
targets for HEV application and were stable for over 275 cycles. We also assembled and
characterized ―high safety‖ batteries with electrolytes based on pure IL, PYR 14 TFSI with
0.4m LiTFSI as lithium salt, and on mixture of this IL and standard electrolyte
(PYR 14 TFSI 50% w/w and EC DMC LiPF 6 50% w/w), using titanium-based anodes (TiO 2
and Li 4 Ti 5 O 12 ) that are commonly considered safer than graphite in abusive conditions.
The batteries bearing the pure ionic liquid did not satisfy the targets for HEV application,
but the batteries with Li 4 Ti 5 O 12 anode and 50-50 mixture electrolyte were able to surpass
the targets. We also assembled and characterized a lithium battery (with lithium metal
anode) with a polymeric electrolyte based on poly-ethilenoxide (PEO 20 –
LiCF 3 SO 3 +10%ZrO 2 ), which satisfied the targets for EV application and showed a very
impressive cycling stability.
In conclusion, we developed three lithium-ion batteries of different chemistries that
demonstrated to be suitable for application in power-assist hybrid vehicles: graphite/EC
DMC LiPF 6 /LiFePO 4 -C, graphite/PYR 14 TFSI 0.4m LiTFSI with 10% VC/LiFePO 4 -C and
Li 4 T i5 O 12 /PYR 14 TFSI 50%-EC DMC LiPF 6 50%/LiFePO 4 -C. We also demonstrated that
an all solid-state polymer lithium battery as Li/PEO 20 –LiCF 3 SO 3 +10%ZrO 2 /LiFePO 4 -C is
suitable for application on electric vehicles. Furthermore we developed a promising anodic
material alternative to the graphite, based on SnCo amorphous alloy.
20
Kruchinin, Dennis. "Lithium amide mechanisms". Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437356.
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21
Khosravi, Javad. "Production of lithium peroxide and lithium oxide in an alcohol medium". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=103204.
Pełny tekst źródłaStreszczenie:
Experiments to measure (i) the reactivity of lithium peroxide and lithium oxide in ambient air as a function of relative humidity and reactant particle size, (ii) the solubility of lithium hydroxide and lithium hydroxide monohydrate in three alcohols, namely methanol, ethanol and 1 and 2-propanol, as a function of time and temperature, (iii) the efficiency of the production of lithium peroxide in alcohol medium as a function of the concentration of LiOH.H 2O in methanol, the concentration of hydrogen peroxide, the kind of alcohol, the kind of feed material, and temperature and the time of mixing, (iv) the analysis of the precipitates, (v) the temperature of the precipitate decomposition in isothermal and non-isothermal conditions in ambient and neutral conditions as function of time, (vi) the activation energy of the precipitate decomposition, (vii) the temperature of the lithium peroxide decomposition in isothermal and non-isothermal conditions as function of time and (viii) the activation energy of lithium peroxide decomposition were performed.The purpose of the study was to gather the data necessary to evaluate the production of lithium peroxide, Li2O2, and subsequently lithium oxide, Li2O, to be used as a feed for a silicothermic reduction process for the production of metallic lithium. The proposed basis for the production of Li2O2 was the conversion of lithium hydroxide or lithium hydroxide monohydrate by hydrogen peroxide in an alcohol medium. Alcohols were chosen because they are members of a class of non-aqueous solvents that can selectively dissolve the anticipated contaminants while precipitating the desired products.
It was found that the addition of hydrogen peroxide to alcohol solutions containing lithium hydroxide monohydrate resulted in the formation of lithium peroxide as lithium hydroperoxidate trihydrate with eight adduct molecules of methanol, i.e., Li2O2•H2O 2•3H2O•8CH3OH and involved the peroxide group transfer. The optimum conditions for the production of lithium peroxide were found to be (i) the least water concentration in the system (ii) the use of the temperature lower than ambient temperature and (iii) fast separation of the precipitate and raffinate to prevent dissociation of the precipitate or dissolving into the raffinate.
The high solubility of LiOH.H2O and at the same time the low solubility of Li2CO3 and of Li2O2 in methanol resulted in selection of methanol as the best alcohol of those studied for the proposed method of Li2O2 production. It also yielded high purity lithium peroxide. The production of Li2O 2 using H2O2 (35 %wt) required an excess of hydrogen peroxide equal to 2.6 times the stoichiometric amount.
The thermal decomposition of the lithium hydroperoxidate trihydrate precipitate started with the rejection of the adduct methanol molecules, followed by co-evolution of H2O and H2O2 from the resulting Li 2O2•H2O2•H2O. The activation energy of the decomposition reaction of the precipitate was measured as 141 kJ/mol. At temperatures greater than 200°C, lithium peroxide was found to be very reactive with atmospheric air. However, in an argon atmosphere, it rapidly decomposed losing the majority of the oxygen atoms, followed by the gradual slow diffusion of oxygen gas absorbed on the lithium oxide.
22
Petzl, Mathias [Verfasser]. "Zerstörungsfreie Charakterisierung von Lithium-Plating in Lithium-Ionen-Batterien / Mathias Petzl". Ulm : Universität Ulm. Fakultät für Naturwissenschaften, 2015. http://d-nb.info/1076828515/34.
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23
Taylor, David Wayne. "The Lithium concentration dependence of creep in binary Aluminum-Lithium alloys". Thesis, Monterey, California. Naval Postgraduate School, 1989. http://hdl.handle.net/10945/26044.
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24
Jang, Young-Il 1968. "Stability of lithium aluminum manganese oxide cathodes for rechargeable lithium batteries". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9162.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1999.Includes bibliographical references.
Lithium manganese oxides have attracted wide attention as low-cost, nontoxic intercalation cathode materials for rechargeable lithium batteries. In this work, the stability of these compounds during synthesis and in use has been studied in several respects. (1) Phase stability of LiMnO2 polymorphs has been determined under the high temperature synthesis conditions. Effects of temperature, oxygen partial pressure, and dopant (Al) content on the phase stability have been discussed based on a possible stability mechanism. (2) The mechanism of improved cycling stability of electrochemically transformed spinel compared to conventional spinel has been identified. Atomic rearrangement from the ordered rocksalt to spinel type cation ordering results in an antiphase nanodomain structure, which becomes a ferroelastic domain structure during the cubic ---> tetragonal Jahn-Teller transformation, and thereby accommodates the transformation strains. (3) Al-doped spinels exhibit much improved capacity stability at elevated temperatures compared to undoped spinels. This effect has been discussed with respect to proposed mechanisms of Mn dissolution and capacity loss. (4) Magnetic properties are critically influenced by phase stability, cation ordering, and Mn valence in lithium manganese oxides. In the paramagnetic temperature regime, it has been observed that antiferromagnetic interactions between the Mn ions are strongest in the orthorhombic phase among LiMnO2 polymorphs having the average Mn valence of 3+, while decreasing Mn valence strengthens the antiferromagnetic interactions in LixMn2O4 spinel. At temperatures below the paramagnetic temperature regime, spin-glass behavior is observed in both LixMn2O4 and monoclinic LiMnO2 compounds, which is attributed to geometrical frustration due to structure ( cation ordering) and magnetic disorder due to a disordered distribution of Mn valence. As spin-glass behavior is commonly observed in both well-crystallized, conventional spinel and highly disordered, transformed spinel, magnetic characterization cannot easily be used to distinguish the two different spinels.
by Young Il-Jang.
Ph.D.
25
Kwabi, David G. (David Gator). "Electrochemical studies of lithium-oxygen reactions for lithium-air battery applications". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81607.
Pełny tekst źródłaStreszczenie:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 61-63).
Fundamentally understanding reaction mechanisms during Li-O₂ cell operation is critical for implementing Li-air batteries with high reversibility and long cycle life. In this thesis, the rotating ring disk electrode (RRDE) technique has been used to probe the influence of different electrolyte solvents on the stability of the superoxide radical produced on planar glassy carbon and Au electrodes. It was found that the fraction of oxygen reduction reaction current attributable to superoxide generation exhibits a solvent-invariant potential dependence on carbon, with a higher fraction of superoxide produced at lower discharge overpotentials. This trend is in support of a proposed growth model for different Li-O₂ morphologies, where Li-O₂ growth is governed primarily by disproportionation of superoxide at low overpotentials and direct electron transfer at high overpotentials. On Au, superoxide stability exhibits a strong solvent dependence, which can be explained in terms of the effect of the electrolyte solvent basicity on the stability of the Li+-O₂- ion pair. This study highlights the potential use of RRDE as a tool to gain insights into Li-O₂ reaction and growth mechanisms and the contribution of soluble intermediate species to parasitic reactions in practical Li-air batteries.
by David G. Kwabi.
S.M.
26
Valdivia, Christopher E. "Light-induced ferroelectric domain engineering in lithium niobate & lithium tantalate". Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/65500/.
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The influence of illumination on ferroelectric domain engineering in lithium niobate and lithium tantalate is investigated. The conventional method of domain inversion is electric field poling, which suffers from several limitations such as a requirement for photolithography and high-voltage equipment, the formation of inhomogeneous electric fields, and a minimum domain size of micrometres. Through the use of directed laser light, either in the presence or absence of an externally applied electric field, these limitations can be overcome and new fabrication capabilities are revealed. Light-assisted poling is the simultaneous application of an external electric field and laser illumination. Using wavelengths ranging from near-UV to near-IR, the electric field required for domain nucleation was reduced for increasing intensities. This effect was most prominent in crystals highly doped with MgO, achieving a reduction of 90% and 98% for cw and fs-pulsed light, respectively. Arbitrary domain patterns were directly written by the scanning of a focused beam. Periodically poled gratings were formed using periodic intensity patterns via a phase mask, forming domain engineered crystals suitable for quasi-phase-matched nonlinear frequency conversion.
27
Wellington, Iain. "Direct UV writing of structures in lithium niobate and lithium tantalate". Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/50699/.
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This thesis presents results from fabrication of UV direct write structures in lithium niobate and lithium tantalate. Unassisted direct writing of surface channel waveguides using lambda = 244 nm cw light resulted in polarisation specific waveguides fabricated on z- cut crystals. Waveguides were characterised using mode profiles, propagation losses, numerical aperture and refractive index measurements. In z-cut congruent lithium niobate, waveguides were written on the +z and -z faces producing structures that guided TM polarisation only with +z face waveguides exhibiting the lowest propagation loss of ~ 2 dB/cm, a maximum refractive index difference of ~ 8 x 10Surface ferroelectric domain reversal via illumination of single pulsed lambda = 266 nm light through a phasemask on +z face congruent lithium niobate produced ordered alignment of domain lines along the crystallographic y-axes with minimum domain separation width of ~ 2 μm. Results from high temperature exposures and multipulse regimes are presented and a domain formation mechanism is proposed via an Nb anti-site model.
28
Brinkhaus, Linda [Verfasser], i Dirk [Akademischer Betreuer] Guldi. "Degradation Phenomena of Lithium-rich Lithium-Nickel-Cobalt- Manganese-Oxide in Lithium-Ion-Batteries / Linda Brinkhaus. Gutachter: Dirk Guldi". Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2015. http://d-nb.info/1075837618/34.
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29
Paul, Marcus. "Synthesis and characterisation of transition metal-doped lithium niobate and lithium tantalate". Thesis, University of Aberdeen, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319341.
Pełny tekst źródłaStreszczenie:
The study of ferroelectric LiNbO3 and LiTaO3 doped with transition metals involves the characterisation of LiNbO3/LiTaO3 solid solutions in the systems Li2O-Nb2O5-MxOy and Li2O-Ta2O5-MxOy (M = Cr, Mn, Fe, Co, Ni, Cu). Compounds were made by solid state reaction at temperatures between 1000 and 1500°C, depending on the system studied. The emphasis of this work is on the characterisation of the defect structure of LiNbO3/LiTaO3 solid solutions using phase diagram determination, X-ray and neutron powder diffraction, EXAFS, ESR and optical spectroscopy. The valence of the incorporated cations was studied by magnetic measurements. The electrical properties of these materials have been investigated using AC impedance spectroscopy. It can be shown that the physical properties of LiNbO3 and LiTaO3 depend strongly on the defects in the structure which can be controlled by purposeful doping with other cations. Structural refinements of the X-ray and neutron powder diffraction data have shown that the defects arising from nonstoichiometry are accommodated by vacancies created on the Li site. This affects the structure when doped with third cations, giving rise to complex substitution mechanisms Spectroscopic studies have shown that the dopants (Cr3+, Mn2+/Mn3+, Co2+, Ni2+, Cu+, Cu2+) are shifted from the central octahedral position towards the adjacent empty octahedron. The electrical properties of LiNbO3 and LiTaO3, measured by AC impedance spectroscopy, depend strongly on the dopant content: the conductivity generally rises, whereas the activation energy for the electrical conductivity drops with increasing dopant concentration. The microstructure of electroceramics can also be probed by AC impedance spectroscopy and it was shown that the texture of all samples was bad due to poor sintering of the pellets. Longer sintering times did not improve the quality of the ceramics which exhibit a large pore size distribution. An important aspect for future work would be the quality improvement of LiNbO3/LiTaO3 based ceramics.
30
Nordh, Tim. "Lithium titanate as anode material in lithium-ion batteries : -A surface study". Licentiate thesis, Uppsala universitet, Strukturkemi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-267567.
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The ever increasing awareness of the environment and sustainability drives research to find new solutions in every part of society. In the transport sector, this has led to a goal of replacing the internal combustion engine (ICE) with an electrical engine that can be powered by renewable electricity. As a battery for vehicles, the Li-ion chemistries have become dominant due to their superior volumetric and gravimetric energy densities. While promising, electric vehicles require further improvements in terms of capacity and power output before they can truly replace their ICE counterparts. Another aspect is the CO2 emissions over lifetime, since the electric vehicle itself presently outlives its battery, making battery replacement necessary. If the lifetime of the battery could be increased, the life-cycle emissions would be significantly lowered, making the electric vehicle an even more suitable candidate for a sustainable society. In this context, lithium titanium oxide (LTO) has been suggested as a new anode material in heavy electric vehicles applications due to intrinsic properties regarding safety, lifetime and availability. The LTO battery chemistry is, however, not fully understood and fundamental research is necessary for future improvements. The scope of this project is to investigate degradation mechanisms in LTO-based batteries to be able to mitigate these and prolong the device lifetime so that, in the end, a suitable chemistry for large scale applications can be suggested. The work presented in this licentiate thesis is focused on the LTO electrode/electrolyte interface. Photoelectron spectroscopy (PES) was applied to determine whether the usage of LTO would prevent anode-side electrolyte decomposition, as suggested from the intercalation potential being inside the electrochemical stability window of common electrolytes. It has been found that electrolyte decomposition indeed occurs, with mostly hydrocarbons of ethers, carboxylates, and some inorganic lithium fluoride as decomposition products, and that this decomposition to some extent ensued irrespective of electrochemical battery operation activity. Second, an investigation into how crossover of manganese ions from Mn-based cathodes influences this interfacial layer has been conducted. It was found, using a combination of high-energy x-ray photoelectron spectroscopy (HAXPES) and near-edge x-ray absorption fine structure (NEXAFS) that although manganese is present on the LTO anode surface when paired with a common manganese oxide spinel cathode, the manganese does little to alter the surface chemistry of the LTO electrode.
31
Imanishi, Nobuyuki. "STUDY ON LITHIUM INSERTION COMPOUNDS AS ELECTRODE MATERIALS FOR LITHIUM SECONDARY BATTERY". Kyoto University, 1993. http://hdl.handle.net/2433/168867.
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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものであるKyoto University (京都大学)
0048
新制・論文博士
博士(工学)
乙第8064号
論工博第2663号
新制||工||898(附属図書館)
UT51-93-B336
(主査)教授 竹原 善一郎, 教授 曽我 直弘, 教授 小久見 善八
学位規則第4条第2項該当
32
Madsen, Alex. "Lithium iron sulphide as a positive electrode material for rechargeable lithium batteries". Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/355748/.
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Lithium iron sulphide has been investigated as a low-cost, high energy density and relatively safe positive electrode material for secondary lithium batteries. Lithium iron sulphide was synthesised, characterised and compared with natural pyrite samples and was shown to have a capacity of 350 mAh.g-1 upon cycling between 1.45 and 2.80 V vs. Li. The capacity was attributed to the Fe2+/Fe3+ redox couple at potentials up to 2.55 V, and oxidation of sulphur sites from Fe3+(S2-)2 to Fe3+S2-(S2)2-0.5 up to 2.80 V. The cycle life performance of lithium iron sulphide is poor when the cell is cycled between 1.45 and 2.80 V, with the cell loosing approximately 1.4 mAh.g-1 per cycle, although this performance is superior to comparable pyrite electrodes. Calcium doped samples of lithium iron sulphide were synthesised. Calcium doping was shown to impact upon lithium transport properties of the bulk lithium iron sulphide, improving the rate performance of the material. Improvements in cycle life performance of the calcium doped samples were offset by decreased specific capacity due to lithium substitution. The poor cycle life performance of lithium iron sulphide cells was attributed to the utilisation of the high voltage plateau corresponding to sulphur site oxidation/reduction. Experiments utilising a variety of negative electrode materials has identified the formation of soluble polysulphide species upon cycling of the cell, which reduce irreversibly at the negative electrode, contributing to active mass loss and poor cycle life performance. In-situ XRD studies have highlighted the structural decomposition that occurs upon utilisation of the sulphide, which results in irreversible amorphisation of the lithium iron sulphide crystal structure. Lithium iron sulphide was treated via coating with lithium boron oxide glass and a novel carbon coating method via thermal decomposition of butyl-methyl-pyrrolydinium-dicyanimide. Both treatments were shown to increase the cycle life performance of lithium iron sulphide, due to decreased dissolution of polysulphide upon cycling. The choice of binder, electrode formulation and electrolyte was also shown to impact upon the cycle life performance of lithium iron sulphide cells.
33
Rossouw, Margaretha Hendrina. "Synthesis and characterization of lithium-manganese-oxide electrodes for lithium battery applications". Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/18339.
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As the electronics industry moves more towards portable equipment the demand for batteries, especially rechargeable batteries, is increasing. Lithium batteries have several advantages over other competitive systems. Coupled with the inexpensive and environmentally friendly manganese dioxide, Li/MnO₂ batteries are being used extensively for powering a range of devices, but particular electronic systems.
34
Rida, Hania. "Nouvelles données sur les systèmes graphite-lithium-europium et graphite-lithium-calcium". Thesis, Nancy 1, 2011. http://www.theses.fr/2011NAN10019/document.
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La méthode solide-liquide en milieu alliage fondu à base de lithium a permis ces dernières années la synthèse de plusieurs composés d'intercalation du graphite (CIG) insérés à coeur au sein des systèmes graphite-lithium-alcalino-terreux. Dans le cadre de cette thèse, cette méthode de synthèse a été étendue aux systèmes graphite-lithium-lanthanoïde, avec une difficulté supplémentaire qui est la méconnaissance des diagrammes de phases binaires lithium-lanthanoïde dont les données sont capitales pour déterminer les domaines de température et de composition chimique des alliages susceptibles de conduire à des CIG. L'immersion de plaquettes de pyrographite dans certains alliages lithium-europium judicieusement choisis a mené à un composé binaire EuC6 ainsi qu'à un composé ternaire graphite-lithium-europium de premier stade.La cinétique de formation de EuC6 a été suivie par diffraction des rayons X ex situ afin de comprendre les différentes étapes de la réaction et d'identifier les phases intermédiaires menant au composé final thermodynamiquement stable. Ce mécanisme révèle un processus réactionnel plus « coopératif » que celui menant au composé CaC6 et a été décrit par une succession d'étapes contribuant à l'insertion à coeur de l'europium.La composition élémentaire du composé ternaire a été déterminée grâce à une analyse par faisceau d'ions qui a permis de doser simultanément les trois éléments lithium, carbone et europium. Le résultat de cette analyse a conduit à la formule chimique Li0,25Eu1,95C6. EuC6 a également été étudié par microsonde nucléaire, le rapport atomique C/Eu de 6 a ainsi notamment pu être confirmé.Des études structurales ont été menées pour les composés binaires et ternaires. D'une part, il a été possible d'effectuer la résolution structurale complète du binaire EuC6, qui cristallise dans une maille hexagonale de groupe d'espace P63/mmc. D'autre part pour le ternaire Li0,25Eu1,95C6, la séquence d'empilement poly-couche selon l'axe c du feuillet inséré a été modélisée, par combinaison des données structurales avec les informations issues de l'analyse par faisceau d'ions.Les composés d'intercalation du graphite sont des solides de basse dimensionnalité qui se prêtent idéalement à l'étude des relations structure-propriétés. Ainsi dans le système graphite-lithium-calcium, le caractère supraconducteur des composés CaC6 et Li3Ca2C6 a été étudié par spectroscopie de spin de muon ([mu]SR). Pour le système graphite-lithium-europium, des mesures magnétiques réalisées préalablement à ce travail ont été poursuivies et complétées par des analyses [mu]SR (pour Li0,25Eu1,95C6 et EuC6) ainsi que par spectrométrie Mössbauer de 151Eu (pour Li0,25Eu1,95C6) à basse températureThe molten alloy solid-liquid method containing lithium has recently enabled the synthesis of several bulk graphite intercalation compounds (GICs) in graphite-lithium-alkaline earth metal systems. As part of this thesis, this synthesis method was extended to graphite-lithium-lanthanide systems, with an additional difficulty which is the lack of knowledge of lithium-lanthanide binary phase diagrams whose data are crucial for determining the temperature range and chemical composition of alloys that may lead to GICs.The immersion of pyrographite platelets in some europium-lithium alloys wisely chosen led to a binary EuC6 compound as well as a graphite-lithium-europium first stage ternary compound.Kinetics study of EuC6 compound was followed by ex situ X-ray diffraction in order to understand the different reaction steps and identify intermediate phases leading to the thermodynamically stable final compound. This mechanism revealed a reaction process more "cooperative" than that leading to CaC6 binary compound and was described by a succession of steps that contribute to the bulk insertion of europium.The elementary composition of the ternary compound was determined by ions beam analysis allowing the simultaneous quantification of the three elements lithium, carbon and europium. The refinement of these analyses led to the chemical formula Li0,25Eu1,95C6 for the ternary compound. EuC6 has also been studied by nuclear microprobe analysis, and especially the C/Eu atomic ratio equal to 6 has been confirmed.Structural studies have been undertaken for binary and ternary compounds. On one hand, it was possible to fully resolve the three-dimensional structure of the binary EuC6, which crystallizes in a hexagonal unit cell with P63/mmc space group. On the other hand, the c axis stacking sequence of the poly-layered intercalated sheet of the ternary compound was modeled by combining structural data with information from the ions beam analysis. The graphite intercalation compounds are low-dimensional solids that are ideal for the study of structure-properties relations. Thus in graphite-lithium-calcium system, superconducting character has been studied for CaC6 and Li3Ca2C6 compounds by muons spin spectroscopy ([mu]SR). For the graphite-lithium-europium system, previous magnetic measurements have been continued and supplemented by [mu]SR analysis (for Li0,25Eu1,95C6 and EuC6) and by low temperature 151Eu Mössbauer spectroscopy (for Li0,25Eu1,95C6)
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Hsiao, Kuang-Che. "Synthesis, characterisation and properties of lithium pyrophosphate materials for lithium battery applications". Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/6693/.
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Bramham, Janice. "Lithium-7 NMR investigations of the biological behaviour of the lithium ion". Thesis, University of St Andrews, 1993. http://hdl.handle.net/10023/14768.
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This thesis reports an investigation of the uptake of Li+ into human erythrocytes using quantitative 7Li-nmr spectroscopy. It was found that the erythrocytes of psychiatric patients, who were on long term lithium therapy for the treatment of bipolar affective disorder, accumulated more Li+, and attained an apparent steady-state concentration more rapidly than did the erythrocytes of healthy controls, not taking lithium. This phenomena was shown to be due, at least in part, to a Li+-induced effect resulting from the treatment of these patients with Li+. Indeed, prior to treatment the uptake of LI+ into the erythrocytes from all the patients was similar to that in the erythrocytes of the healthy controls. This Li+-induced effect is consistent with the inhibition of the Na+-Li+ countertransport mechanism, the predominant Li+ efflux pathway in erythrocytes, which has previously been shown to be inhibited by Li+. The uptake of Li+ into cultured cells was also monitored by 7Li-nmr spectroscopy, by growing the cells upon the surfaces of microcarrier beads. Excellent spectra were obtained from which the uptake of Li+ was found to be approximately ten-fold faster than that into erythrocytes, with the steady- state being achieved more rapidly. In an attempt to rationalise the altered transport behaviour of erythrocytes exposed to Li+ in vivo, the effect of this cation upon the major components of the erythrocyte membrane were investigated by TLC and gel electrophoresis. However, no significant differences were observed in either the relative amounts of the lipids, or in the major protein content of the erythrocyte membranes from Li+-treated patients and from healthy controls not taking lithium. 7Li-nmr spectroscopy was also employed to investigate the interaction between Li+ and the enzyme, inositol monophosphatase, however under the conditions of the experiment no interaction was observed. Finally, a brief study of the transport behaviour of the Cs+ ion across the human erythrocyte membrane using 133Cs-nmr spectroscopy is reported. The uptake of Cs+ into the erythrocytes of patients suffering from alcohol-dependence syndrome, the erythrocytes of whom are reported to contain abnormally high levels of Cs+, was found to be virtually identical to that of abstinent controls.
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Mast, Ernest. "Lithium production from spodumene". Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55633.
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Muller, Catherine R. "Lithium amides in synthesis". Thesis, University of Oxford, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413176.
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Broughton, Duncan Andrew. "Hydrolysis of lithium hydride". Thesis, University of Reading, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394063.
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Flack, Keith W. "Defects in lithium oxide". Thesis, University of Kent, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238119.
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Thomas, Geraint Mark Howard. "Lithium and phosphoinositide metabolism". Thesis, University of Wolverhampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238120.
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Barry, Ian Eric. "Microstructuring of lithium niobate". Thesis, University of Southampton, 2000. https://eprints.soton.ac.uk/15498/.
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This thesis presents the results from an investigation into methods for micron-scale relief structuring of lithium niobate. A wet etch consisting of HF and HNO3 was applied, and directed by 1) patterning the ferroelectric domain structure of the samples and 2) illuminating the crystals with patterned 488nm light. Post-etch treatment of the structures resulted in ridge waveguides and alignment grooves, while pre-etch manipulation achieved an etch-stop. Ablation was investigated as a method of directly structuring the crystal and for patterning photoresist. The etch was found to leave the +z face untouched. The -z face was etched at a rate, k, in µm/hour given by k = e 20.37 - 6300/T where T is the absolute temperature. This differential etch rate reveals a pattern induced in the ferroelectric domain structure by the technique of electric field patterning. The structures had walls with roughness < 5nm. Straight walls were easily achieved aligned along the y-direction at 120o to this. Other directions can result in facetted walls. Ridge waveguide losses <1dBcm-1, fibre alignment grooves and an etch stop were demonstrated using appropriate pre- and post-etch treatments. The etch was found to be affected by illumination with 488nm radiation. In Fe:LiNbO3 complete and partial frustration of the etch was induced on the -z face. Characteristic features of the partial frustration were sub-micron ridges and triangular pillars, separated by gaps as small as 500nm. In LiNbO3 the etch rate was found to increase on the -z face. The etch rate on the +z face was unaffected in both. Direct ablation with an excimer laser produced relief structures. Aspect ratios > 1:1 resulted in a dendritic structure in the ablated area. Direct ablation was suitable for patterning the photoresist. Surface damage was intentionally induced when producing large (>100µm) openings, however, the effect of surface damage on electric field poling could not be conclusively tested. Submicron openings were also created and subsequent poling produced sub-micron domains, revealed by etching.
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Senyshyn, A., M. Monchak, O. Dolotko i H. Ehrenberg. "Lithium Diffusion and Diffraction". Diffusion fundamentals 21 (2014) 4, S.1, 2014. https://ul.qucosa.de/id/qucosa%3A32392.
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In the current contribution the application of bond valence method for the prediction (and diffraction-based techniques for the evalution) of ion diffusion pathways in different materials
for electrochemical energy conversion and storage will be presented and discussed.
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Margheim, Steven J. "Lithium in the Pleiades". [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3252776.
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Thesis (Ph.D.)--Indiana University, Dept. of Astonomy, 2007.Title from PDF t.p. (viewed Nov. 19, 2008). Source: Dissertation Abstracts International, Volume: 68-02, Section: B, page: 1022. Adviser: Constantine Deliyannis.
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Wise, David. "Processing hard rock lithium". Thesis, Wise, David (2018) Processing hard rock lithium. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/41925/.
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The focus of this thesis project has been on recovering lithium from its mineral ores, primarily being from spodumene. The general process for recovering lithium has been to begin with a roast to improve the dissolution rate of lithium ions. This occurs by expanding the crystal structure from an alpha to beta-spodumene form. However, this initial roast contributes a significant energy expense in processing the ore.
This project has aimed at finding an alternative, less expensive pre-treatment for recovering lithium from spodumene ores. The attempt has been to use a caustic leach within an autoclave at an elevated pressure of 40 bar and moderate temperatures of 150 to 250°C. A 0.01M acid digestion followed at temperature of 50°C for 12 hours. The obtained results were from Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-Ray Diffraction, which indicated a very poor extraction. The x-ray peaks did however indicate a potential change in crystal structure. Overall, the experiment remained as a work in progress with the identification of newly formed x-ray peaks still being required. Solid residue analysis has also been helpful in providing a conclusive account of the mineral elements.
There were three sections covered in this study. The first phase has involved preparing a comprehensive literature review to give a general overview of the lithium industry. The literature review is located within Appendix A. The second phase was then to develop a planned laboratory procedure, while covering an adequate risk assessment and budgetary proposal. These planning activities are within the Program of Study that is located within Appendix B. The final phase was then to apply the practical autoclave leaching experiments on mineral samples. The body of this thesis contains the laboratory report, which presents the applied procedure and the analysis of results. The main intention was to identify efficiencies, reduce costs and provide more an effective lithium recovery option, for commercial use.
The literature review has targeted the world’s lithium resources along with the various technologies that exist for its extraction from primary and secondary deposits. The acid leaching, alkaline, ion-exchange, pressure leaching, bioleaching and chlorination processes have been examined for processing the primary mineral ores of spodumene, lepidolite, amblygonite, petalite, zinnwaldite and clays. Brine resources; have also been explored with its extraction process techniques of adsorption, precipitation and ion exchange through solvent extraction. The secondary resource of recycling lithium ion batteries (LIBs) have then evaluated as an alternative source and explained in detail. This has involved an initial pre-treatment of the spent LIBs, acid leaching of the metals and recovery of the lithium and by-product compounds from the leach liquors. The suitable recycling processes to handle the varying compositions of available batteries have also contributed. Another secondary resource has been lithium’s presence in seawater; however, this source has been ignored as an uneconomical supply due to its very low concentration. Overall, the key industrial extraction procedures were critically examined with reference to various journal articles and patents. The essential objective has been to provide a detailed description of the available lithium recovery techniques that are applied to the various reserves.
The second phase was to complete a program of study. This involved outlining the project objectives, intended materials and equipment items. The identification of potential health and safety aspects were include with major risks examined. This involved an overview of the toxicity of materials and potential hazards within the laboratory workplace and a risk assessment with control measures being completed. The intended experimental procedure was then outlined which targeted the operation of the autoclave equipment, the sulphuric acid process and the caustic treatment options. A laboratory plan was developed to optimise several testing parameters for an autoclave leach. This plan involved adjusting the leaching reagents, their concentration, the temperature, pulp density, grind size and ore variability. The remainder of the program of study then budgeted and scheduling the activities and expected outcomes. Overall, this second section was a planning procedure to determine the direction of the project.
The final phase was then to complete the practical laboratory procedures and an analysis of the obtained results. Once completed, this developed a laboratory report that is the body of this thesis article. This section introduces the reasons for the intended procedure, lists the actual materials and method applied before evaluating the results. Major changes to the laboratory plan were identified, before focusing attention on presenting and discussing the results. Overall, the planned variation of leaching conditions has been replaced. A variation of caustic leaching reagents were instead implemented at varying temperatures, with the solid residues then being treated with a secondary acid wash. The conclusion section then summarizes the results and suggests any further testing recommendations.
The literature review and program of study have been placed in Appendix A and B due to a word limitation within the body of this article. As such, the body only contains the final laboratory report.
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Queval, Pierre. "Phosphures borane de lithium". Caen, 2011. http://www.theses.fr/2011CAEN2053.
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Les phosphures borane de lithium sont des espèces obtenues par déprotonation de phosphines borane secondaires par une base de type alkyllithien. L’analyse de ces composés, dont la structure est peu connue, par spectroscopie de résonance magnétique nucléaire multinoyaux a mis en évidence des interactions entre les atomes de lithium et d’hydrogènes du groupement borane et l’absence d’interaction PLi. En accord avec la structure de ces composés, une réactivité duale de P-nucléophile et de réducteur a été mise en évidence par réaction avec des dérivés carbonylés. L’issue de la réaction dépend des conditions imposées à la réaction : cinétique (produit de P-addition) ou thermodynamique (produit de réduction). Le processus de réduction a également conduit à des oligomères linéaires de phosphines borane. Dans une seconde partie, la synthèse de phosphines borane P-énantioenrichies a été effectuée par dédoublement dynamique thermodynamique de phosphures borane encombrés en présence d’amines énantiopures dérivées de 3-aminopyrrolidines, offrant pour la première fois un accès aux dérivés de configuration (S). Les phosphures borane de lithium sont des espèces obtenues par déprotonation de phosphines borane secondaires par une base de type alkyllithien. L’analyse de ces composés, dont la structure est peu connue, par spectroscopie de résonance magnétique nucléaire multinoyaux a mis en évidence des interactions entre les atomes de lithium et d’hydrogènes du groupement borane et l’absence d’interaction PLi. En accord avec la structure de ces composés, une réactivité duale de P-nucléophile et de réducteur a été mise en évidence par réaction avec des dérivés carbonylés. L’issue de la réaction dépend des conditions imposées à la réaction : cinétique (produit de P-addition) ou thermodynamique (produit de réduction). Le processus de réduction a également conduit à des oligomères linéaires de phosphines borane. Dans une seconde partie, la synthèse de phosphines borane P-énantioenrichies a été effectuée par dédoublement dynamique thermodynamique de phosphures borane encombrés en présence d’amines énantiopures dérivées de 3-aminopyrrolidines, offrant pour la première fois un accès aux dérivés de configuration (S)Lithium phosphido-boranes are anionic species prepared by deprotonation of secondary phosphane-boranes using an organolithium base. Multinuclear NMR analysis of these poorly studied compounds evidenced lithium-hydrides interactions and absence of lithium-phosphorus one. According to their structure, these compounds develop a dual reactivity behaving as both P-nucleophile and reducing agent using carbonyl compounds as substrates. The issue of the reaction depends on the kinetic or thermodynamic control imposed to the reaction medium: P-addition or reduction, respectively. Linear polyphosphinoboranes have also been formed during the reduction process. In a second part, P-enantioenriched phosphane-boranes have been synthesized starting form sterically hindered phosphane-boranes using enantiopure amines derived from 3-aminopyrrolidine as chiral agents. This approach, involving a thermodynamic dynamic resolution process, leads for the first time to tertiary P-stereogenic phosphane-boranes, having the (S)-configuration
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Ecker, Madeleine [Verfasser]. "Lithium Plating in Lithium-Ion Batteries : An Experimental and Simulation Approach / Madeleine Ecker". Aachen : Shaker, 2016. http://d-nb.info/1106838440/34.
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Tsukamoto, Hisashi. "Synthesis and electrochemical studies of lithium transition metal oxides for lithium-ion batteries". Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327428.
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Nguyen, Trang Thi Thu. "Hydrogen release and absorption in mixed anion lithium amide/lithium ternary nitride systems". Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6671/.
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In this work, reactions of either LiBH\(_4\), ZnCl\(_2\) or Zn\(_3\)N\(_2\) with LiNH\(_2\) have been studied. The presence of CoO significantly affected the products and hydrogen release on heating mixtures of χLiBH\(_4\)-γLiNH\(_2\). The ratios of the l4\(_1\)/amd and the P2\(_1\)/c polymorphs of Li\(_3\)BN\(_2\) in the products have been changed under different conditions studied. On addition of CoO, the temperature of hydrogen release from the χLiBH\(_4\)-γLiNH\(_2\) systems was greatly reduced, starting from 100°C and peaking around 250°C, much lower than 240°C and 330°C without catalyst. Ball-milling helped to improve the amounts of hydrogen desorbed from 3–4 wt% up to ≥10 wt%. In the reactions of ZnCl\(_2\) + nLiNH\(_2\) (where \(\textit n\) = 2–6), main products were LiCl, Zn\(_3\)N\(_2\), and LiZnN. NH\(_3\) was the main gas released from these reactions and the addition of LiH changed NH\(_3\) into H\(_2\), which was released around 90°C, much lower than in the absence of LiH. A mixture of LiZnN and LiCl obtained from this reaction was partly rehydrogenated to form Li\(_2\)NH and Zn. The reaction of Zn\(_3\)N\(_2\) and LiNH\(_2\) was found to produce pure LiZnN without LiCl. Neither pure LiZnN nor Zn\(_3\)N\(_2\) could be hydrogenated under the conditions tried, but a mixture resulting from the reaction could react with H\(_2\) to form LiNH\(_2\) and Zn. The cyclability of the Li–Zn–N system showed an ability to release and take up gases under different pressure conditions. Mg-doping in LiZnN was examined to improve reversibility of the Li–Zn–N system but was not successful.
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DU, PASQUIER AURELIEN. "Synthese et evaluation d'electrolytes polymeres pour generateurs secondaires au lithium et ion lithium". Paris 6, 1996. http://www.theses.fr/1996PA066318.
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Le present travail decrit la preparation d'electrolytes polymeres pour generateurs secondaires au lithium selon deux strategies differentes: une premiere approche a ete de modifier une molecule de poe en y incorporant par polytransesterification des fonctions carbonates de maniere a diminuer son taux de cristallinite et a augmenter ainsi sa conductivite ionique a temperature ambiante. Dans une seconde approche sont etudies les gels a base de carbonate d'ethylene et du sel litfsi, qui ont ete choisis pour leurs bonnes proprietes d'interface avec l'electrode de lithium. L'effet des interactions polymere-sels de lithium et polymere- solvant sur les proprietes electrochimiques des gels est mis en evidence par l'utilisation de trois polymeres-modeles: le poe le pan et le pmma, qui presentent des affinites variees pour le solvant et le sel de lithium. Enfin, la cyclabilite d'electrodes de graphite, d'accumulateurs li/ppy, li/v#2o#5, lixc#6/licoo#2 et lixc#6/linio#2 est etudiee dans les meilleurs electrolytes polymeres mis en evidence par ce travail