Spelling suggestions: "subject:"1ithium ion battery"" "subject:"alithium ion battery""
121 |
Selected Examples of NMR Spectroscopy Towards the Characterization of Next Generation Lithium Ion Battery MaterialsPauric, Allen January 2017 (has links)
The research described here encompasses several different aspects of lithium ion battery operation including deep eutectic electrolytes, manganese trapping evaluation, silicon monoxide anodes, and in-situ NMR development under both static and spinning conditions. Individually, the results of these investigations as contained within the corresponding chapters contribute valuable insight. Collectively, they represent a snapshot into the numerous different ways in which nuclear magnetic resonance spectroscopy is applicable to lithium ion battery characterization. For instance, the deep eutectic electrolytes thus studied were amenable to diffusion coefficient characterization via the 1H, 7Li and 19F nuclei. This provided dynamical information on the anion, cation and neutral component and lent itself well towards parameterization of molecular dynamics simulations. The results thus obtained were useful in describing this relatively understudied class of electrolytes. Another example is that of the evaluation of manganese trapping. In this context 7Li NMR measurements were used to investigate the competitive inhibition of manganese trapping in crown ethers by lithium. Candidate crown ethers were thus evaluated for their ability to trap Mn2+ and Mn3+ in a lithium rich environment. Given the detrimental effects that manganese dissolution from cathode materials has on cycle life performance, the NMR enabled assessment of the appropriate chelating agents had identifiable importance. Additionally described was the progress made with silicon monoxide anodes supported on cellulosic substrates. The high active material loadings achieved, while also intriguing from a performance perspective, enabled 29Si MAS-NMR and 7Li static in-situ NMR measurements. For the in-situ measurements in particular, a novel cell design was constructed to utilize the advantages of a cellulosic substrate in this context. This has also enabled preliminary work on a spinning in-situ design. / Thesis / Doctor of Philosophy (PhD)
|
122 |
Investigation of Silicon-Based and Multicomponent Electrodes for High Energy Density Li-ion BatteriesSturman, James 29 November 2023 (has links)
Li-ion batteries have enabled the widespread adoption of portable electronics and are becoming the technology of choice for electric vehicles and grid storage. One of the most promising ways to accommodate this demand is to increase the energy density and cycle life of battery electrode materials. Key strategies promoted in the literature include the use of nickel-rich cathodes as well as high-capacity anodes like silicon and lithium metal. While these materials enable a high energy density, this advantage is often counterbalanced with deficits such as poor stability and high cost. Multicomponent electrodes refer to strategies that try to leverage the relative advantages of different materials to offer an attractive compromise of energy density, cost, and cycle life. This thesis has investigated various aspects of multicomponent electrodes with a special emphasis on silicon-based anodes and high-entropy materials.
Silicon (Si) is the second-most abundant element on earth and has one of the highest gravimetric capacities. However, silicon anodes are notorious for their poor cycle stability. Herein, improvements in the stability of silicon-based electrodes are achieved with multicomponent composite strategies involving the use of nanostructured spherical silicon. The nanosilicon is studied in high-fraction (80 wt% Si) and low-fraction (≤20 wt% Si) formulations to investigate both failure mechanisms and practical capacity retention, respectively. Composite strategies in which nanosilicon is encapsulated within a Li₄Ti₅O₁₂ ceramic or MOF-derived carbon matrix are shown to deliver superior capacity retention compared to simple composites of silicon and graphite. Considerable attention is given to the selection of a water-soluble binder and its role in electrochemical stability and electrode cohesion in high-loading silicon electrodes. It is found that unmodified high-molecular-weight sodium carboxymethyl cellulose offers better capacity retention compared to xanthan gum or low-molecular-weight binders.
The high-entropy design strategy has created a diverse and largely unexplored set of multicomponent oxides and alloys with great potential as electrode materials. This strategy is applied to the family of layered cathodes, where the synthesis and electrochemical properties of the best-performing Li(NiCoMnTiFe)₁O₂ are reported. Despite the low Ni content, the cathode delivers a high initial capacity with unique overlithiation stability despite being charged to 4.4 V.
Throughout the thesis, Operando XRD is used to reveal important insight into the lithiation mechanisms of the multicomponent electrodes including intercalation-based graphite, alloying-based silicon, and a novel organic azaacene.
|
123 |
Om packmaterial för transport av litiumjonbatterier : Brandegenskaper och arbetsmiljö / On packing material for transport of lithium-ion batteries : Fire properties and working environmentHansson, Petter, Ohlsson, Sanna January 2022 (has links)
As the climate issue has affected most vehicle manufacturers, the number of electric cars in the world has increased in recent years. Scania's goal is that by 2030, 50 % of all their trucks sold in Europe will be powered by electricity. There are currently legal requirements for how transportation of batteries by road is allowed, depending on if the batteries are damaged, defective or prototype batteries. Scania currently has a method to transport these batteries. The working method consists of a safety box that is filled with the packing material Pyrobubbles in which the batteries are placed. However, Scania wants a better understanding of the function of Pyrobubbles, the safety box and its advantages and disadvantages, as well as whether there are better solutions. The work therefore intends to sort out these issues. In addition to reviewing the thermal properties of the materials, the work has been carried out from a SHE perspective on Scania’s request. This means that safety, health and the environment are taken into account. A literature study was conducted to investigate which alternative packaging materials were available as option to Pyrobubbles, as well as other manufacturers that are available for the safety box. Seven different packaging materials have been examined in the report, these are; absol, sorbix, vermiculite, sand, Pyrobubbles, glass- and stone wool. Two experimental studies were performed to investigate the properties of packing materials. All materials were tested in the cone calorimeter as three different experimental setups; dry, damp and inside a rust protection bag. Two full-scale experiments were also carried out where Pyrobubbles and rockwool were tested as packing material. In addition, a bow tie was created regarding the handling of packing material and an investigation of the ergonomics was conducted. The rust protection bag that is currently used at Scania to facilitate the packaging of Pyrobubbles contributes to unwanted heat release. The lowest heat release and best insulation capacity were measured for the sand. However, the sand is unmanageable to work with as it has a high density and contains carcinogenic particles. Rockwool is considered a good alternative to Pyrobubbles, which partly facilitates the work situation for employees and is also more accessible than Pyrobubbles. In order for rockwool to be accepted as a packing material, a certification of packing material and safety box must be done together, which applies to all new solutions. Keywords: Pyrobubbles, Lithium-ion battery, battery safety, ADR-S
|
124 |
Developing a Life Cycle Assessment model for an electric motorcycleKumar, Avinash January 2022 (has links)
Transport is one of the most carbon-intensive sectors in the world today. With increasing global population and economy, the share of emissions is expected to rise. Electric vehicle is one of promising technology that helps address this challenge. The electric vehicle segments of companies have broadened, and their sales have increased in the past decade. The electric motorcycle sector is growing fast, with the development of improved technology on electric powertrains, increased ranges, charging speeds and infrastructure. Parallel to the sales of these vehicles, the electric battery sector is advancing rapidly, thereby lowering the environmental impacts of these vehicles. The competitive adventure sport sector also benefits from using electric powertrains by taking advantage of their power-to-weight ratio and instant torque. The benefits of using electric vehicles can be seen during the use phase with zero tailpipe emissions and clean, silent riding. But with the expansion of the electric motorcycle sector rolling out new technologies and models, there are uncertainties as to whether the overall lifecycle of the vehicles have reduced impacts on the environment. To make improvements and to find the most sustainable models or solutions, it is important to analyse the impacts of the electric bikes on the environment.A case study has been performed at CAKE 0 Emission AB, in Stockholm, Sweden for the purpose of evaluating potential environmental impacts of KALK OR, an off-road electric two wheeler. This is achieved by carrying out a stand-alone assessment of KALK OR, to identify potential environmental hotspots. The study investigated the potential of manufacturing the motorcycle fossil-free. Attributional life cycle assessment was employed as a methodology with an explicit focus on nine impact categories at midpoint level. The results of the study indicated Suspensions, Frame, and battery to be the highest contributor of environmental impact. The common among them is one material, Aluminium. Battery on the other hand contributes highly on mineral resource scarcity, 26%. Other aspects and assumptions are also analyzed further using a sensitivity analysis, which shows the scope for decreasing KALK OR’s environmental footprint. Using this findings, three companies were selected to help reduce the environmental impact and their emission reduction potential was evaluated. It was found that using recycled aluminium could significantly reduce the global warming impact by 15% and the overall reduction from the Cleanest dirt bike ever project at the time of study could be 29.06%. Based on the results, it is recommended to use recycled aluminium. Additionally, from the various transport scenarios, it is recommended to avoid flight as that could lead to massive environmental impact. / Transportsektorn är idag en av världens mest utsläppstyngda branscher, med förväntad ökning av utsläppen i takt med växande befolkning. Elektrifiering av fordon ses som en av lösningarna för att hantera branschens problem. Det senaste decenniet har utbudet av elektriska fordon breddats och företag inom segmentet har sett stigande försäljningssiffror. Marknaden för elektriska motorcyklar växer snabbt, i takt med att både infrastruktur och den tekniska utvecklingen av elektriska drivlinor förbättras, med längre räckvidd och snabbare uppladdning som resultat. Även utvecklingen av batterier avancerar i raketfart, med möjlighet att minska klimatavtrycket för elfordon som kategori. Äventyrssport är ännu ett område där elektriska drivlinor kan konkurrera med sina fördelar genom fördelaktig effekt till-vikt förhållande och snabba vridmoment, utöver tyst och utsläppsfri körning i naturen. Trots de uppenbara fördelarna under körning råder det osäkerhet kring de elektriska elmotorcyklarnas miljöpåverkan ur ett livscykelperspektiv. För att styra utvecklingen av miljövänliga elmotorcyklar åt rätt håll är det helt centralt att analysera fordonets miljöpåverkan under hela livscykeln. I syfte att utvärdera miljöpåverkan under hela livscykeln för den elektriska off-road motorcykeln Kalk OR, har en studie genomförts hos CAKE 0 emission AB i Stockholm, Sverige. Studien har genomförts med utförandet av en fristående livscykelanalys på modellen Kalk OR, med målet att identifiera potentiell negativ miljöpåverkan, under samtliga faser av motorcykelns livscykel. Fallstudien undersökte möjligheterna för helt eliminera koldioxidutsläppen under produktionsfasen.En attributiv livscykelanalys utfördes med särskilt fokus på nio karakteriseringsfaktorer i mittpunkt. Resultatet indikerade att ram, stötdämpare och batteri var de delar med störst negativt avtryck på miljön. En gemensam nämnare för dessa delar är materialet aluminium. Batteri bidrar även till avtryck på knappa fossila resursers 26%. Fler aspekter och antaganden analyserades med hjälp av en känslighetsanalys för att påvisa möjligheterna för att minska fotavtrycket på miljön för modellen Kalk OR. Baserat på livscykelanalysen valdes tre leverantörer ut med potential att reducera fotavtrycket för Kalk OR. Företagens potential och lösningar utvärderades med insikten att återvunnen aluminium kan reducera Kalk OR:s bidrag till den globala uppvärmningen med 15%. Den totala reduceringen av koldioxidutsläpp för the Cleanest Dirt Bike Ever vid tiden för studien uppskattades till 29.06%.
|
125 |
FABRICATION AND EVALUATION ON ELECTROCHEMICAL PERFORMANCE OF SOLID POLYMER ELECTROLYTE MEMBREANE FOR LITHIUM-ION BATTERYRen, tianli, ren January 2017 (has links)
No description available.
|
126 |
Physical and electrochemical investigation of various dinitrile plasticizers in highly conductive polymer electrolyte membranes for lithium ion battery applicationFeng, Chenrun January 2017 (has links)
No description available.
|
127 |
CURRENT OSCILLATIONS DURING COPPER ELECTRODISSOLUTION IN LITHIUM ION BATTERY AND ACIDIC CHLORIDE ELECTROLYTESCui, Qingzhou 20 December 2006 (has links)
No description available.
|
128 |
Multinuclear NMR Studies of Ion Mobility Pathways in Cathode Materials for Lithium Ion BatteriesDavis, Linda J. 04 1900 (has links)
<p>This thesis investigates the structure and ion mobility properties within the phosphate and fluorophosphate family of cathode materials for Li ion batteries using solid-state NMR. Developments in lithium ion battery technology are now directed towards automotive applications meaning that many of the cost and safety issues associated with current lithium ion battery technology need to be addressed. Within the current systems the high cost is largely attributed to the use of LiCoO<sub>2</sub> as the positive electrode. Many new and inexpensive Li intercalation materials have been put forward as alternatives to LiCoO<sub>2</sub>, however the details concerning the structural and ion-transport properties of these new phases are not well defined. <sup>6,7</sup>Li, <sup>31</sup>P, and <sup>19</sup>F NMR measurements are an ideal tool to study these properties, as <sup>6,7</sup>Li is able to probe the local environment and dynamics of the mobile ion while <sup>31</sup>P and <sup>19</sup>F monitor changes in the host framework. Materials selected for study in this thesis include olivine LiFePO<sub>4</sub>, monoclinic Li<sub>3</sub>M<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> (M = V, Fe), the tavorite-based Li<sub>2</sub>VPO<sub>4</sub>F and Li<sub>2</sub>VOPO<sub>4</sub>, and the novel layered Li<sub>5</sub>V(PO<sub>4</sub>)<sub>2</sub>F<sub>2</sub>. The fluorophosphates have been introduced as higher voltage cathode materials for lithium batteries, however our <sup>6,7</sup>Li 1D selective inversion and 2D EXSY measurements reveal timescales of ion hopping that are relatively slow when compared to those measured in the phosphates. This indicates that the improved power output from the voltage gains may be lost to slow charge/discharge rates.</p> / Doctor of Philosophy (PhD)
|
129 |
LITHIUM MAS NMR STUDIES OF LITHIUM ION ENVIRONMENT AND ION DYNAMIC PROCESS IN LITHIUM IRON AND MAGNESIUM PYROPHOSPHATE AS NEW SERIES OF CATHODE MATERIALS FOR LITHIUM ION BATTERIESHe, Xuan 04 1900 (has links)
<p>Lithium-ion batteries provide a more cost-effective and non-toxic source of reusable energy compare to other energy sources. Several research studies have lead to production of some more promising cathode components for lithium ion batteries. Recently, a new series of pyrophosphate-based composition Li<sub>2</sub>FeP<sub>2</sub>O<sub>7</sub> and Li<sub>2</sub>MnP<sub>2</sub>O<sub>7</sub> has been reported as cathode materials. They have shown a 3D framework structure and the two Lithium-ions in the three-dimensional tunnel structure make it possible that more than one lithium ion be extracted during cycling. Lithium solid state nuclear magnetic resonance (NMR) is an effective technique to study this cathode material, not only for analyzing local structure, but also for investigation of the microscopic processes that take place in the battery.</p> <p>In this work, Li<sub>2</sub>FeP<sub>2</sub>O<sub>7</sub> and Li<sub>2</sub>MnP<sub>2</sub>O<sub>7</sub> have been synthesized. The lithium environment of these materials is studied using 1D <sup>6,7</sup>Li NMR. Assignment of Li<sub>2</sub>MnP<sub>2</sub>O<sub>7</sub> spectrum has been made based on Fermi-contact interaction and crystal structure. Both variable temperature experiment and 1D selective inversion NMR are used to establish Li-ion pathways as well as Li hopping rates for Li<sub>2</sub>MnP<sub>2</sub>O<sub>7</sub>. Also, <sup>7</sup>Li MAS NMR measurements are used to characterize Li environments in LixFeP<sub>2</sub>O<sub>7 </sub>after being electrochemically cycled to different points, and preliminary results regard to changes to ion mobility in LixFeP<sub>2</sub>O<sub>7 </sub>at different electrochemical cycled points are presents here, solid-solution (de)lithetiation process is confirmed for this material.</p> / Master of Science (MSc)
|
130 |
Electron Microscopy Study of the Chemical and Structural Evolution of Lithium-Ion Battery Cathode MaterialsLiu, Hanshuo 11 1900 (has links)
Layered lithium transition metal oxides represent a major type of cathode materials that are widely used in commercial lithium-ion batteries. Nevertheless, these layered cathode materials suffer structural changes during electrochemical cycling that could adversely affect the battery performance. Clear explanations of the cathode degradation process and its initiation, however, are still under debate and are not yet fully understood. In this thesis, the cycling-induced chemical and structural evolution of LiNi1/3Mn1/3Co1/3O2 (NMC) and high-energy Li1.2Ni0.13Mn0.54Co0.13O2 (HENMC) cathodes are investigated in details using state-of-the-art electron microscopy techniques combined with other bulk measurements to uncover the mechanisms at the source of cell deterioration. / Thesis / Doctor of Philosophy (PhD)
|
Page generated in 0.082 seconds