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Wezenberg, Udo. "An engineering geological investigation of batter stability, Weavers opencast coal mine, Huntly." Thesis, University of Canterbury. Geology, 1988. http://hdl.handle.net/10092/9397.
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Cut slope batter instability of overburden in Weavers Opencast Mine at Huntly involves 0-65m succession of Waikato Coal Measures and Glen Afton Claystone of the Te Kuiti Group (Eocene to Oligocene), and a 15-65m sequence of overlying gravels, pumiceous sands, silts, clays and peats of the Tauranga Group (Pliocene to Holocene). Field and laboratory investigations were conducted to determine the causes and mechanisms of cut batter instability. Field investigations included: detailed engineering geological mapping of the entire highwall at a scale of 1:1584; detailed batter logging and sampling of lower Tauranga Group materials and defect orientation surveys of Te Kuiti Group and Tauranga Group for stereographic analysis of failure modes. Laboratory investigations included: shear strength testing of the Te Kuiti-Tauranga Group unconformity contact and representative joint and bedding planes in the lower Tauranga Group; X.R.D. and chemical tests for clay mineralogy, grainsize distribution, atterberg limits, field moisture content, density and void ratio determination for Tauranga Group Materials.
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Zhao, Lei. "Three-dimensional numerical study on the batter instability mechanism of Maddingley Brown Coal Open Pit, Victoria, Australia using PLAXIS 3D." Thesis, Federation University Australia, 2019. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/172972.
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With the increased size of excavation due to long-term open cut mining, batter instability has become a major geo-hazard in Victorian Brown Coal Open Pits where facilitate some largest brown coal mining operations in the world. Block failure is a unique failure mode in Victorian brown coal mines, which is often associated with cracks and rainfall. Maddingley Brown Coal Mine (MBC) is located in Bacchus Marsh, Victoria, Australia. Slope instability has also been a major geo-problem since the open pit mining commenced in MBC in 1940s. Making clear the cracking mechanism and the correlations between rainfall and batter instability have important implications in better understanding and predicting batter failures in Victorian brown coal mines. In this research, three-dimensional geologic models were developed to investigate the mechanism of brown coal batter instability. The finite element program encoded in Plaxis 3D was employed to conduct the complex two-phase (fluid-solid) coupled numerical simulations. The results revealed the cracking mechanism of coal batter and the effects of rainfall on batter stability. It was found that the brown coal batter with overburden tends to lead a circular critical path while the batter after overburden removal shows a trend of block sliding as interpreted by the shear and tensile strains simulated. The existence of joints and the hydrostatic water pressure in the joints could adversely affect the stability of brown coal batter towards block failure. Precipitation can increase the deformation, excess pore pressure, total pore pressure, active pressure and decrease the matric suction, and thereby decrease the shear strength, effective stress, and batter stability. The results from the three-dimensional hydro-mechanically coupled finite element study were well agreed with the field monitored data, theoretical calculations, and Victorian brown coal mining experience.Doctor of Philosophy
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Chaiwanichsiri, Saiwarun. "Changes in rheological properties, particle size and cooking stability of meat batter as a function of fat content and time and temperature of chopping /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265555441386.
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Perdigao, Cristhiana. "Assessment of horizontal bore drains performance in brown coal mines in the Latrobe Valley." Thesis, Federation University Australia, 2021. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/181877.
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Horizontal bores are essential infrastructures for maintaining the stability of open-pit mine batters. The infiltration of water from large surface catchments during rain events and induced deformation caused by mining activities can cause the build-up of pore water pressures in mine batters, potentially leading to catastrophic slope failures. A field investigation unit containing a camera has been developed to survey long (>300m) horizontal bores. Features observed using the camera along the profile of horizontal bores are discussed. Water flow was quantified by flow meters. X-Ray Diffraction (XRD) was undertaken to investigate the water precipitates within the selected bores. Water flow temperature was recorded to test the hypothesis of a possibility to indicate whether a borehole was draining from the saturated zone or from the surface water through its temperature. The investigations have been conducted to determine the cause of change in the efficiency of horizontal boreholes and find a reliable measure to assess longevity and performance of horizontal drains. Bore efficiency has been defined as the bore functioning as a preferential path for water within the batter to be drained out to reduce the saturated zone and associated pore water pressures within the batter. The results suggest blockages and fractures inside the bores can be considered the leading cause of the change in the efficiency of a bore. Blockages occur because of sediment accumulation and because of coal chunks from internal wall collapses. Internal fractures affect efficiency when they become the water preferred path; thus, retaining water flowing within the batter. The bore’s longevity is considered the period of the bore is considered effective. Water flow measurement is suggested as a reliable measure to assess bores’ longevity.Masters by Research
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Chen, Yuhui. "Stability and recharging of aprotic Li-O₂ batteries." Thesis, University of St Andrews, 2014. http://hdl.handle.net/10023/6350.
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Non-aqueous rechargeable lithium-air (O₂) batteries are receiving intense interest because of their high theoretical specific energy, which are several times greater than that of lithium-ion batteries. To achieve it, the highly reversible formation/decomposition of Li₂O₂ is required to occur in the cathode during cycling. Due to the reactivity of reduced O₂ species, the aprotic electrolyte and carbon electrode substrate would be attacked and then decomposed. The organic carbonate decomposed on discharge, forming C₃H₆(OCO₂Li)₂, Li₂CO₃, HCO₂Li, CH₃CO₂Li, CO₂ and H₂O. Part of these by-products decomposed on the subsequent charge process and the rest remained and blocked the electrode surface. Finally, the cell cycling stopped because of the depletion of electrolyte and the passivation of the electrode surface. Possible mechanisms are proposed for reactions on discharge and charge. Some other types of aprotic solvents were investigated in the same way. Ethers, amides, sulfones, dimethyl sulfoxide (DMSO), etc reveal better stability than organic carbonates. Reversible formation/decomposition was observed together with minor side-reactions. Besides electrolytes, carbon substrate of electrode also slightly decomposed. Several other substrate materials were studied. If the carbon electrodes were replaced with the nanoporous gold electrodes, less side-reaction was observed in the cells, and the cell sustained 100 cycles without severe polarisation and capacity fading. The charge performance of a Li-O₂ cell remains a challenge. Great voltage polarisation even at modest rate was observed because of the difficulty of charge transfer between solid electrode surface and solid Li₂O₂. Redox mediators were used in a Li-O₂ cell, which transported the charge between electrode surface and solid Li₂O₂, acting as an electron-hole transfer agent. The oxidation of solid Li₂O₂ was facilitated and the cell with mediator demonstrated 100 charge/discharge cycles.
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Patranika, Tamara. "Investigations of the Thermal Runaway Process of a Fluorine-Free Electrolyte Li-Ion Battery Cell." Thesis, KTH, Kemiteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298355.
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Detta projekt syftar till att undersöka den termiska rusningsprocessen hos ett litiumjonbatteri med en fluorfri elektrolyt och jämföra den med en kommersiellt använd fluor-innehållande elektrolyt. Battericellerna innehöll silikon-grafit som anod och LiNi0.6Mn0.2Co0.2O2 (NMC622) som katod. Den fluorfria elektrolyten var baserad på litium bis(oxalato)borat (LiBOB) i organisk lösning med additivet vinylen karbonat(VC). Det jämfördes med en fluor-innehållande elektrolyt med LiPF6 i samma organiska lösning tillsammans med VC och fluoroetylene karbonat (FEC). De termiska stabilitetstesterna utfördes med Accelerating Rate Calorimetry (ARC) och Differentiell svepkalorimetri (DSC). Både knappceller och pouchceller har undersökts med hjälp av ARC. Trots flera försök med olika uppställning kunde den termiska rusningen inte bli detekterad för någon av celltyperna, med slutsatsen att en störremängd aktivt material behövs. Istället användes DSC för att undersöka de termiska reaktionerna hos batteri-komponenterna. Resultaten visade att anoden var mer termisk stabil med den fluorfria elektolyten, medan samma elektrolyt visade mindre termisk stabilitet på katoden. Vidare undersökningar behövs dock för bekräftelse av katoden.This project aims to investigate the thermal runaway process of fluorine-free lithium ion battery cells and to compare this with a commercially used fluorinated electrolyte. The cells consisted of a silicon-graphite composite anode and a LiNi0.6Mn0.2Co0.2O2(NMC622) cathode. The non-fluorinated electrolyte used was based on lithiumbis(oxalato)borate (LiBOB) in organic solvents with the additive vinylene carbonate(VC). Moreover, the fluorinated electrolyte consisted of LiPF6 in the same organic solvents together with VC and fluoroethylene carbonate (FEC). The thermal stability measurements have included Accelerating Rate Calorimetry (ARC) and Differential Scanning Calorimetry (DSC). Moreover, both coin cells and pouch cells have been examined by ARC. However, thermal runaway could not be detected for either type of cells, concluding that a greater amount of active material was needed. In order to measure the thermal reactions of the battery components, DSC was used. These results concluded that the anode was more thermally stable with a non-fluorinated electrolyte. However, the thermal stability appeared to be lower for the cathode, therefore, further investigation is needed for confirmation of the cathode.
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Zhao, Mingchuan. "Electrochemical Studies of Lithium-Ion Battery Anode Materials in Lithium-Ion Battery Electrolytes." Ohio University / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1004388277.
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Zhang, Tan. "Adaptive Energy Storage System Control for Microgrid Stability Enhancement." Digital WPI, 2018. https://digitalcommons.wpi.edu/etd-dissertations/190.
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Microgrids are local power systems of different sizes located inside the distribution systems. Each microgrid contains a group of interconnected loads and distributed energy resources that acts as a single controllable entity with respect to the grid. Their islanding operation capabilities during emergencies improve the resiliency and reliability of the electric energy supply. Due to its low kinetic energy storage capacity, maintaining microgrid stability is challenging under system contingencies and unpredictable power generation from renewable resources. This dissertation highlights the potential benefits of flexibly utilizing the battery energy storage systems to enhance the stability of microgrids. The main contribution of this research consists in the development of a storage converter controller with an additional stability margin that enables it to improve microgrid frequency and voltage regulation as well as its induction motor post-fault speed recovery. This new autonomous control technique is implemented by adaptively setting the converter controller parameters based on its estimated phase-locked loop frequency deviation and terminal voltage magnitude measurement. This work also assists in the microgrid design process by determining the normalized minimum storage converter sizing under a wide range of microgrid motor inertia, loading and fault clearing time with both symmetrical and asymmetrical fault types. This study evaluates the expandability of the proposed control methodologies under an unbalanced meshed microgrid with fault-induced feeder switching and multiple contingencies in addition to random power output from renewable generators. The favorable results demonstrate the robust storage converter controller performance under a dynamic changing microgrid environment.
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Nilssen, Benedicte Eikeland. "Stability of Conductive Carbon Additives for High-voltage Li-ion Battery Cathodes." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26847.
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Conductive carbon additives are important constituents of the current state-of-the-art Li-ion battery cathodes, as the traditional active cathode materials are characterized by too low electronic conductivities. In high-voltage Li-ion batteries, these additives are subject for anion intercalation and electrolyte oxidation, which might cause changes in the conductive carbon network in the cathode, and hence the overall cycling performance of the electrode. This thesis has focused on study the stability of three types of carbon additives operating at high voltages. Materials included were two conventional types of conductive additives, graphite, KS6, and carbon black, Super P Li, both provided from TIMCAL. In addition, a multilayer graphene powder, Graphene AO-2, provided from Graphene Supermarket has been investigated. The powder properties, size, shape and structure, were studied in a scanning electron microscope and by powder X-ray diffraction. Electrodes from these materials were cycled galvanostatically and with cyclic voltammetry to reveal their high-voltage behaviour, with respect to the two above mentioned electrochemical processes. More detailed investigations of anion intercalation in KS6 and Graphene AO-2 were conducted by in situ X-ray diffraction measurements and scanning electron microscopy. For cycling in 30:70 vol% EC/DMC 1 M LiPF6 to a voltage of 4.7 V vs. Li+/Li, the results showed that Super P Li can be considered as the most stable conductive additive. At 4.7 V vs. Li+/Li, both KS6 and Graphene AO-2 are electrochemically active, while Graphene AO-2 displays a more reversible behavior, and are more stable than KS6. For even higher operation potential, 5.0 V vs. Li+/Li, Graphene AO-2 showed the least stable behavior of the three materials, due to large degree of electrolyte oxidation, unstable anion intercalation upon continuous cycling, and the suggestions of structural degradation of the electrode. However, a small increase in the electrolyte stability window was shown with Graphene AO-2 when changing to a more viscous electrolyte (1:1 vol% EC/DMC 1 M LiPF6) or adding an anion receptor (tris(hexafluoroisopropyl)borate) to the electrolyte. The anion intercalation in KS6 was observed to form staged phases, starting at 4.83 V vs. Li+/Li. The electrode structure was suggested to be affected in a smaller extent compared to Graphene AO-2. In addition, less electrolyte was oxidized at the KS6 electrode surface, compared to the two other materials. However, the film formed on the Super P Li electrodes did not seem to affect the carbon negatively, because stable anion intercalation was observed upon continuous cycling. Indicating that Super P Li was not strongly affected by the intercalation process.
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Georén, Peter. "Characterisation and modelling of lithium-ion battery electrolytes." Doctoral thesis, KTH, Chemical Engineering and Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3650.
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Rechargeable batteries play an important role as energycarriers in our modern society, being present in wirelessdevices for everyday use such as cellular phones, video camerasand laptops, and also in hybrid electric cars. The batterytechnology dominating the market today is the lithium-ion(Li-ion) battery. Battery developments, in terms of improvedcapacity, performance and safety, are major tasks for bothindustry and academic research. The performance and safety ofthese batteries are greatly influenced by transport andstability properties of the electrolyte; however, both haveproven difficult to characterise properly.
The specific aim of this work was to characterise and modelthe electrolytes used in Li-ion batteries. In particular, themass transport in these electrolytes was studied throughcharacterisation and modelling of electrolyte transport in bulkand in porous electrodes. The characterisation methodology assuch was evaluated and different models were tested to find themost suitable. In addition, other properties such aselectrochemical stability and thermal properties were alsostudied.
In the study of electrochemical stability it wasdemonstrated that the electrode material influenced thevoltammetric results significantly. The most versatileelectrode for probing the electrolyte stability proved to beplatinum. The method was concluded to be suitable for comparingelectrolytes and the influences of electrolyte components,additives and impurities, which was also demonstrated for a setof liquid and polymer containing electrolytes.
A full set of transport properties for two binary polymerelectrolytes, one binary liquid and the corresponding ternarygel were achieved. The transport was studied both in the bulkand in porous electrodes, using different electrochemicaltechniques as well as Raman spectroscopy. In general, theconductivity, the salt and solvent diffusivity decreasedsignificantly when going from liquid to gel, and to polymerelectrolyte. Additionally, low cationic transport numbers wereachieved for the polymer and gel and significant salt activityfactor variations were found. The results were interpreted interms of molecular interactions. It was concluded that both theionic interactions and the influences from segmental mobilitywere significant for the polymer containing electrolytes. Thecharacterisation methods and the understanding were improved bythe use of a numerical modelling using a model based on theconcentrated electrolyte theory. It was concluded thatelectrochemical impedance spectroscopy and Raman spectroscopywere insufficient for determining a full set of transportproperties. It was demonstrated that the transport is veryinfluential on electrochemical impedance as well as batteryperformance.
Keywords:lithium battery, electrolyte, mass transport,stability, modelling, characterisation, electrochemical, Ramanspectroscopy, impedance
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Xiao, Neng. "Investigating Growth Mechanism of Potassium Superoxide in K-O2 Batteries and Improvements of Performance and Anode Stability upon Cycling." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1462890425.
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Denoyelle, Quentin. "Microbatteries lithium(-ion) tout solide pour applications haute température." Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0007.
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Le développement de la microélectronique a conduit à l’émergence de capteurs capables de fonctionner à haute température (150 - 250 °C). Les sources d’énergie existantes (batteries conventionnelles, batteries ZEBRA etc.) sont peu ou pas du tout adaptées pour ce genre d’applications. L’utilisation du LiPON, électrolyte céramique stable jusqu’à plus de 200 °C, permet d’envisager l’utilisation des microbatteries comme source d’alimentation à haute température. L’objectif de la thèse consiste à évaluer la possibilité d’utiliser des microbatteries standards de type LiCoO2/LiPON/Li à haute température. La première partie de l’étude porte sur la stabilité en température des différents matériaux de l’empilement, notamment celle des composés délithiés Li1-xCoO2. En parallèle, la deuxième partie de l’étude s’est concentrée sur l’analyse des interfaces entre les différents matériaux, notamment sur l’interface LiCoO2/LiPON. A partir des résultats obtenus sur la stabilité thermique du matériau d’électrode positive et sur sa réactivité vis-à-vis de l’électrolyte, son remplacement est étudié dans la troisième partie afin d’obtenir un empilement plus robuste à haute température. L’étude du composé Li2FeS2 et de l’interface avec le LiPON a permis de montrer des résultats encourageants pour l’application viséeThe development of microelectronics has led to the manufacture of sensors able to operate at high temperatures (150 - 250 °C). For this kind of application, available power sources (conventional batteries, ZEBRA batteries etc.) are poorly or not adapted at all to this kind of applications. The use of LiPON, a ceramic electrolyte stable until high temperature, suggests that microbatteries could be used for high temperature current supplying. The aim of this work is to estimate the sustainability of standard microbatteries LiCoO2/LiPON/Li at high temperature. The first part of the study focuses on the thermal stability of the different materials of the stack, especially on delithiated compounds Li1-xCoO2. In parallel, the second part of the study is devoted to the interfaces between the different materials, focusing on the LiCoO2/LiPON interface. Given the results obtained on the thermal stability of the positive electrode material and its reactivity with the electrolyte, the third part deals with the electrode material substitution in order to make a more robust stack at high temperature. The study of Li2FeS2 and its interface with the electrolyte leads to promising results with regard to the aimed application
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Kanchanaharuthai, Adirak. "Small-Signal Stability, Transient Stability and Voltage Regulation Enhancement of Power Systems with Distributed Renewable Energy Resources." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1321988036.
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Knoche, Thomas [Verfasser], and Mathias [Akademischer Betreuer] Ulbricht. "Novel porous membranes with enhanced stability as lithium ion battery separator / Thomas Knoche ; Betreuer: Mathias Ulbricht." Duisburg, 2016. http://d-nb.info/1120923468/34.
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Bangash, Kashif Naeem. "Investigation of stability of smart distribution network with high DGs penetration using battery energy storage systems." Thesis, Glasgow Caledonian University, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.726755.
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Cao, Jinwei. "Phase Diagram Approach to Control of Ionic Conductivity and Electrochemical Stability of Solid Polymer Electrolyte Membrane for Li-ion Battery Application." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1398789082.
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Zandi, Majid. "Contribution au pilotage des sources hybrides d’énergie électrique." Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL071N/document.
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Ce mémoire traite du pilotage de systèmes hybrides de puissance électrique. Les sources principales d’énergie sont un système photovoltaïque et une pile à combustible. Les sources secondaires sont un pack de batteries et un pack de supercondensateurs. Le dimensionnement des sources secondaires est réalisé afin de gérer les transitoires de puissances et de fournir l’appoint d’énergie lorsque celle issue des sources principales est insuffisante. Les sources principales, quant à elles, fournissent l’énergie à la charge en régime permanent. Le contrôle des flux d’énergies et les asservissements de puissance utilisés dans cette thèse sont basés sur le concept de platitude des systèmes différentiels. Ils permettent d’obtenir des propriétés dynamiques élevées en asservissement et en régulation. Le superviseur, permettant de répartir la puissance entre les différents organes de stockage, est réalisé à base de contrôleur flou et assure que les supercondensateurs avec leur convertisseur d’interface sont utilisés comme filtre de puissance et apportent l’énergie en régime transitoire. En revanche, les batteries fournissent ou absorbent l'énergie sur des durées plus longuesThis thesis deals with the control of electrical hybrid system. The main sources consist in an association of photovoltaic and fuel cell system. The secondary sources are a bank of batteries and a bank of supercapacitors. The sizing of secondary sources is realized to manage the power during the transient state and provide extra energy when the power of main sources is insufficient in steady state. The main sources provide the essential energy of the electrical hybrid system during steady state. The control of energy flows and power tracking used in this thesis are based on the flatness technique. This control system allows obtaining high dynamic properties in the power tracking and the regulation of system. The supervisor for sharing the power between the different storage devices is realized thanks to a fuzzy logic controller. This controller ensures that the bank of supercapacitors with its interface converter is used as a power filter and provides the energy in transient states. However, the bank of batteries provides or absorbs the energy in longer periods especially during recovery or overload modes
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Stjerndahl, Mårten. "Stability Phenomena in Novel Electrode Materials for Lithium-ion Batteries." Doctoral thesis, Uppsala University, Department of Materials Chemistry, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8214.
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Li-ion batteries are not only a technology for the future, they are indeed already the technology of choice for today’s mobile phones, laptops and cordless power tools. Their ability to provide high energy densities inexpensively and in a way which conforms to modern environmental standards is constantly opening up new markets for these batteries. To be able to maintain this trend, it is imperative that all issues which relate safety to performance be studied in the greatest detail. The surface chemistry of the electrode-electrolyte interfaces is intrinsically crucial to Li-ion battery performance and safety. Unfortunately, the reactions occurring at these interfaces are still poorly understood. The aim of this thesis is therefore to increase our understanding of the surface chemistries and stability phenomena at the electrode-electrolyte interfaces for three novel Li-ion battery electrode materials.
Photoelectron spectroscopy has been used to study the surface chemistry of the anode material AlSb and the cathode materials LiFePO4 and Li2FeSiO4. The cathode materials were both carbon-coated to improve inter-particle contact. The surface chemistry of these electrodes has been investigated in relation to their electrochemical performance and X-ray diffraction obtained structural results. Surface film formation and degradation reactions are also discussed.
For AlSb, it has been shown that most of the surface layer deposition occurs between 0.50 and 0.01 V vs. Li°/Li+ and that cycling performance improves when the lower cut-off potential of 0.50 V is used instead of 0.01 V. For both LiFePO4 and Li2FeSiO4, the surface layer has been found to be very thin and does not provide complete surface coverage. Li2CO3 was also found on the surface of Li2FeSiO4 on exposure to air; this was found to disappear from the surface in a PC-based electrolyte. These results combine to give the promise of good long-term cycling with increased performance and safety for all three electrode materials studied.
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Krause, Andreas, Susanne Dörfler, Markus Piwko, Florian M. Wisser, Tony Jaumann, Eike Ahrens, Lars Giebeler, et al. "High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-217538.
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We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.
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Krause, Andreas, Susanne Dörfler, Markus Piwko, Florian M. Wisser, Tony Jaumann, Eike Ahrens, Lars Giebeler, et al. "High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability." Nature Publishing Group, 2016. https://tud.qucosa.de/id/qucosa%3A30116.
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We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.
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Showers, Obu Samson. "Enhanced frequency regulation functionality of grid-connected PV system." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/3070.
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Thesis (MEng (Electrical Engineering))--Cape Peninsula University of Technology, 2019Electric utilities are confronted with challenges like rising fuel costs, aging equipment, increasing energy demand, frequency regulation and the difficulty to integrate renewable energy resources into the grid. The presence of photovoltaic (PV) penetration on the utility grid is also increasing significantly in recent years. With the recent rise in PV penetration and the advancement of the global PV industry, there is an urgent and a necessary need to introduce features in PV systems that will make them respond smartly. However, much of these can be addressed without negatively affecting the total performance and power quality of the grid. Hence, engaging smart Grid technologies, and leveraging the benefits of the distributed nature of PV, new prospects to unearth value can be created. Through the implementation of progressive energy storage techniques, efficient two-way communications, a grid-tied PV system can create significant value, mostly through improved PV contribution in grid support functions like frequency regulation. An enhanced frequency regulation functioning scheme for a grid-connected photovoltaic (PV) system is modelled in MATLAB/Simulink software environment. The system is designed to operate in grid ancillary services precisely, frequency regulation function. The model consists of a Photovoltaic (PV) plant with a battery connected to the grid through a three-phase inverter. A bi-directional DC-DC converter between the grid and the battery system is included. The model has a battery storage system that provide steady and regular active/reactive powers available while the grid transmit specific amounts of power needed for a specific duration. According to the design, either the grid or the PV system depending on the dominant energy situation charges the battery. The battery is designed to discharge only when the grid demands energy from the PV and if the PV system fails to meet the demanded active power or reactive power. The PV system and the battery storage is integrated with the grid with the aid of dc-ac inverter in such a manner that bi-directional flow of active and reactive power is achieved. A 1 MW PV system is connected to the utility grid through a three-phase voltage source inverter system. The grid nominal frequency is set at 50 Hz under normal operation. However, the frequency decreased when the PV was not producing required power hence, the battery responded almost instantaneously and returned the frequency to the nominal frequency. The effectiveness of battery storage system for utility grid frequency regulation was substantiated from the simulation results attained.
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Zhou, Quan, Zongbin Zhao, Zhiyu Wang, Yanfeng Dong, Xuzhen Wang, Yury Gogotsi, and Jieshan Qiu. "Low temperature plasma synthesis of mesoporous Fe₃O₄ nanorods grafted on reduced graphene oxide for high performance lithium storage." Royal Society of Chemistry, 2014. https://tud.qucosa.de/id/qucosa%3A36296.
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Transition metal oxide coupling with carbon is an effective method for improving electrical conductivity of battery electrodes and avoiding the degradation of their lithium storage capability due to large volume expansion/contraction and severe particle aggregation during the lithium insertion and desertion process. In our present work, we develop an effective approach to fabricate the nanocomposites of porous rod-shaped Fe₃O₄ anchored on reduced graphene oxide (Fe₃O₄/rGO) by controlling the in situ nucleation and growth of β-FeOOH onto the graphene oxide (β-FeOOH/GO) and followed by dielectric barrier discharge (DBD) hydrogen plasma treatment. Such well-designed hierarchical nanostructures are beneficial for maximum utilization of electrochemically active matter in lithium ion batteries and display superior Li uptake with high reversible capacity, good rate capability, and excellent stability, maintaining 890 mA h g⁻¹ capacity over 100 cycles at a current density of 500 mA g⁻¹.
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Gu, Yu. "A PVDF-BASED HYBRID ELECTROLYTE INCORPORATING LATP AND Al2O3 FILLERS WITH ENHANCED IONIC CONDUCTIVITY AND THERMAL STABILITY FOR LI-ION BATTERIES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=case1618903524872759.
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Hung, Duong Quoc. "Smart integration of distributed renewable generation and battery energy storage." Thesis, The University of Queensland, 2014. https://espace.library.uq.edu.au/view/UQ:342027.
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Renewable energy (i.e., biomass, wind and solar) and Battery Energy Storage (BES) are emerging as sustainable solutions for electricity generation. In the last decade, the smart grid has been introduced to accommodate high penetration of such renewable resources and make the power grid more efficient, reliable and resilient. The smart grid is formulated as a combination of power systems, telecommunication communication and information technology. As an integral part of the smart grid, a smart integration approach is presented in this thesis. The main idea behind the smart integration is locating, sizing and operating renewable-based Distributed Generation (DG) resources and associated BES units in distribution networks strategically by considering various technical, economical and environmental issues. Hence, the aim of the thesis is to develop methodologies for strategic planning and operations of high renewable DG penetration along with an efficient usage of BES units.
The first contribution of the thesis is to present three alternative analytical expressions to identify the location, size and power factor of a single DG unit with a goal of minimising power losses. These expressions are easily adapted to accommodate different types of renewable DG units for minimizing energy losses by considering the time-varying demand and different operating conditions of DG units. Both dispatchable and non-dispatchable renewable DG units are investigated in the study. Secondly, a methodology is also introduced in the thesis for the integration of multiple dispatchable biomass and nondispatchable wind units. The concept behind this methodology is that each nondispatchable wind unit is converted into a dispatchable source by adding a biomass unit with sufficient capacity to retain the energy loss at a minimum level. Thirdly, the thesis studies the determination of nondispatchable photovoltaic (PV) penetration into distribution systems while considering time-varying voltage-dependent load models and probabilistic generation. The system loads are classified as an industrial, commercial or residential type or a mix of them with different normalised daily patterns. The Beta probability density function model is used to describe the probabilistic nature of solar irradiance. An analytical expression is proposed to size a PV unit. This expression is based on the derivation of a multiobjective index (IMO) that is formulated as a combination of three indices, namely active power loss, reactive power loss and voltage deviation. The IMO is minimised in determining the optimal size and power factor of a PV unit. Fourthly, the thesis discusses the integration of PV and BES units considering optimal power dispatch. In this work, each nondispatchable PV unit is converted into a dispatchable source by adding a BES unit with sufficient capacity. An analytical expression is proposed to determine the optimal size and power factor of PV and BES units for reducing energy losses and enhancing voltage stability. A self-correction algorithm is then developed for sizing multiple PV and BES units. Finally, the thesis presents a comprehensive framework for DG planning. In this framework, analytical expressions are proposed to efficiently capture the optimal power factor of each DG unit with a standard size for minimising energy losses and enhancing voltage stability. The decision for the optimal location, size and number of DG units is obtained through a benefit-cost analysis over a given planning horizon. Here, the total benefit includes energy sales, loss reduction, network investment deferral and emission reduction, while the total cost is a sum of capital, operation and maintenance expenses.
The study reveals that the time-varying demand and generation models play a significant role in renewable DG planning. Depending on the characteristics of demand and generation, a distribution system would accommodate up to an estimated 48% of the nondispatchable renewable DG penetration. A higher penetration level could be obtained for dispatchable DG technologies such as biomass and a hybrid of PV and BES units. More importantly, the study also indicates that optimal power factor operation could be one of the aspects to be considered in the strategy of smart renewable DG integration. A significant energy loss reduction and voltage stability enhancement can be achieved for all the proposed scenarios with DG operation at optimal power factor when compared to DG generation at unity power factor which follows the current standard IEEE 1547. Consequently, the thesis recommends an appropriate modification to the grid code to reflect the optimal or near optimal power factor operation of DG as well as BES units. In addition, it is shown that inclusion of energy loss reduction together with other benefits such as network investment deferral and emission reduction in the analysis would recover DG investments faster.
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Yokoyama, Yuko. "Studies on Electrolytes for High-Voltage Aqueous Rechargeable Lithium-ion Batteries." Kyoto University, 2019. http://hdl.handle.net/2433/242525.
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Chiappori, Guido Jose. "Système de stabilisation de la tension batterie pour la fonction Stop-Start automobile : solution à composants de puissance commandés en linéaire." Thesis, Ecole centrale de Lille, 2015. http://www.theses.fr/2015ECLI0005/document.
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Cette thèse présente un nouveau système de stabilisation de la tension batterie spécialement destinés aux véhicules Stop-Start, économique et compact, nommé LVSS (Linear Voltage Stabilization System). Le LVSS se comporte comme une résistance variable et limite le courant à l’aide de transistors MOSFET fonctionnant en mode linéaire. Il permet donc de stabiliser la tension de la batterie pendant le démarrage du moteur à combustion interne (ICE). Un prototype a été conçu et testé sur une voiture. Les résultats ont montré que la tension était stabilisée tout en limitant le courant de démarrage. De plus la solution proposée n’impacte pas sur les performances globales du système Stop-Start et comme les transistors fonctionnent en mode linéaire, cette solution n’émet pas de perturbations CEMThis thesis presents a new Linear Voltage Stabilization System (LVSS) specially designed for µ-hybrid vehicles using the Stop-Start function. The LVSS stabilizes the battery voltage during the start-up of the Internal Combustion Engine (ICE) limiting the start-up current using parallels MOSFETs working in linear mode. A prototype was developed and tested in a car. Results have shown the battery voltage properly stabilized limiting the start-up current. Furthermore the proposed solution does not impact on the overall performance of the Stop-Start. Main advantages are its small volume, low price and the fact that there is no EMC perturbation as transistors work in linear mode
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He, Ruixuan. "Studies on Ionic Conductivity and Electrochemical Stability of Plasticized Photopolymerized Polymer Electrolyte Membranes for Solid State Lithium Ion Batteries." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1478969519588062.
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Chancelier, Léa. "Développement de solutions innovantes d'électrolytes pour sécuriser les accumulateurs lithium-ion." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10208/document.
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Les batteries lithium-ion dominent le marché des appareils nomades et celui des véhicules électriques. Néanmoins elles posent des problèmes de sécurité liés à leur électrolyte, contenant des carbonates inflammables et volatils. Pour sécuriser ces systèmes, les liquides ioniques (LI) sont étudiés comme électrolytes alternatifs. Ce sont des sels liquides à température ambiante, réputés stables thermiquement et non inflammables. Ce caractère sécuritaire des LI, souvent avancé, est pourtant peu étayé par des expériences probantes. Les travaux de cette thèse visent à comprendre le comportement de ces LI en situations abusives, telles qu'un échauffement de la batterie, un feu ou une surcharge. Les températures de décomposition de LI contenant les cations imidazolium ou pyrrolidinium différemment substitués et l'anion bis(trifluoromethanesulfonyl)imide ont été déterminées par analyse thermogravimétrique (ATG). Une analyse critique des données (de la littérature et de nos mesures) a permis de définir une procédure optimisée, pour obtenir des résultats reproductibles et comparables. Des électrolytes constitués de mélanges de carbonates ou de LI et de sels de lithium ont été analysés par ATG dynamique et isotherme, et leurs produits de décomposition ont été identifiés. Leur comportement au feu a été testé par la mesure des chaleurs de combustion, des délais d'inflammation et l'identification des gaz générés. Des tests de cyclage électrochimique ont été menés avec ces mêmes électrolytes dans des systèmes lithium-ion constitués des électrodes Li4Ti5O12 et LiNi1/3Mn1/3Co1/3O2. L'évolution des électrolytes et des surfaces des électrodes en situation de surcharge a été examinéeLithium-ion batteries are dominating both the nomad device and electric vehicle markets. However they raise safety concerns related to their electrolyte, which consists of flammable and volatile carbonate mixtures and toxic salts. The replacement of the latter by ionic liquids (IL), liquid salts claimed to be thermally stable and non-flammable, could provide a safer alternative. Yet this often claimed feature has been poorly examined by experiments. The work of this thesis investigates IL behaviour under abuse conditions such as overheating, fire or overcharge. Decomposition temperatures of IL based on differently substituted imidazolium or pyrrolidinium cations and the bis(trifluoromethanesulfonyl)imide anion were determined by thermogravimetric analysis (TGA). A critical study of gathered data (from literature and our work) led to the determination of an optimised procedure to obtain reproducible and comparable results. Electrolytes based on carbonates mixtures or IL and containing lithium salt were studied by dynamic and isothermal TGA, and their decomposition products were identified. Their combustion behaviour was also tested by measuring heats of combustion and ignition delays. Emitted gases were analysed and quantified. Electrochemical cycling tests were carried out with these electrolytes in lithium-ion systems based on Li4Ti5O12 and LiNi1/3Mn1/3Co1/3O2 electrodes. The evolution of the electrolytes and electrodes surface was also examined under overcharge
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Costantini, Elia. "Analisi dinamica e ottimizzazione delle prestazioni per velivoli multirotore." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
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Oggetto della presente trattazione sono lo studio della stabilità statica e dinamica e l’ottimizzazione delle prestazioni per velivoli multirotore di piccola/media taglia.
La tesi è divisa in tre principali macroaree: analisi dinamica, analisi delle prestazioni, dimensionamento e sviluppi futuri.
Nella prima sezione, a partire dallo studio delle principali derivate aerodinamiche, è possibile analizzare la stabilità del velivolo; inoltre, come si dimostrerà ampiamente, essa può essere incrementata tramite opportune soluzioni costruttive, quali angoli di tilt e diedro.
Nella seconda sezione, dato un multirotore con una certa configurazione ed un determinato peso, si desidera ricavare il tempo di volo in una condizione di hover, che è funzione della potenza richiesta. In particolare, per quanto concerne questa macroarea, sono stati sfruttati dati sperimentali provenienti da test al banco prova e relativi a eliche di svariate dimensioni, in termini di diametro e passo. La possibilità di utilizzare tali dati è stata di rilevanza assoluta, poiché ha permesso di affinare minuziosamente la stima della potenza, soprattutto per quanto riguarda il coefficiente di potenza indotta.
Nella sezione finale si desidera trovare la batteria ottimale da equipaggiare ad un velivolo multirotore, noti la geometria ed il peso a vuoto. A tal proposito si è anche ricavata una “curva di sensibilità”, estremamente utile, ad esempio, per un progettista, poiché consente di capire come si modificano le prestazioni al variare della capacità nominale della batteria.
Ciascuna macroarea termina con un caso applicativo, che permette la validazione dei codici MATLAB implementati.
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Berhaut, Christopher Logan. "Propriétés de transport des sels de lithium LiTDI et LiFSI : application à la formulation d'électrolytes optimisés pour batteries Li-ion." Thesis, Tours, 2016. http://www.theses.fr/2016TOUR4017/document.
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La plupart des batteries Li-ion aujourd’hui utilisent des électrolytes à base de LiPF6 un sel de lithium connu pour son instabilité chimique au-delà de 60°C car il se dégrade en libérant PF5 et LiF. En présence de traces d’eau il génère en plus des composés oxyfluorophosphorés et du HF qui peut être dommageable à la fois pour les performances et pour le vieillissement de l’accumulateur. Plusieurs sels sont candidats au remplacement de LiPF6, notamment ceux basés sur les anions fluorosulfonylamidures et les anions de Hückel. Ce travail concerne l’étude des propriétés physico-chimiques et de transport des électrolytes à base de 4,5-dicyano-2- (trifluoromethyl)imidazolide de lithium (LiTDI) et bis(fluorosulfonyl)amidure de lithium (LiFSI) pour une utilisation au sein d’accumulateurs de type Li-ion. Dans ce travail il a d’abord été montré que LiTDI n’est que faiblement dissocié dans les mélanges de carbonates d’alkyles utilisés dans les batteries Li-ion tels que le binaire (EC/DMC) ce qui limite sa conductivité. Pour pouvoir remédier à cet inconvénient, une étude des phénomènes de solvatation et d’associations ioniques a été menée et a conduit à proposer un mélange ternaire de solvants (EC/GBL/MP) dans lequel LiTDI est plus dissocié. Le mélange ternaire proposé améliore à la fois les propriétés de transport et les caractéristiques thermiques de l’électrolyte sans compromettre le domaine de stabilité chimique et électrochimique. Enfin, le nouvel électrolyte EC/GBL/MP contenant LiTDI, a été testé en accumulateurs dans les conditions opératoires usuelles (régime C/10 et température ambiante) et sévères (régime 10C et des températures allant de -20 °C à 60 °C). Le problème de corrosion de l’aluminium de LiFSI a aussi été pris en compte. Un électrolyte prometteur à base d’un mélange LiTDI/LiFSI montrant de meilleures performances que chaque sel utilisé séparément dans EC/DMC a été présenté. Les conclusions de cette thèse prouvent que LiTDI ou LiFSI peuvent être utilisés comme sels de lithium dans les électrolytes pour accumulateurs Li-ionMost of the Li-ion batteries used in electrical devices contain a solution of LiPF6 in alkylcarbonate solvents with the risk of releasing PF5 at elevated temperatures and HF in the presence of water. Several salts are candidates for the replacement of LiPF6, including those based on fluorosulfonylamides and Hückel anions. This work concerns the study of physicochemical and transport properties of lithium 4,5-dicyano-2- (trifluoromethyl)imidazolide (LiTDI) and lithium bis(fluorosulfonyl)amide (LiFSI) based electrolytes and their use in Li-ion battery. First it was revealed that LiTDI is only weakly dissociated in alkylcarbonate mixtures used in Li-ion batteries such as EC/DMC limiting its conductivity. To overcome this disadvantage, a study of the solvation phenomena and of ionic association within the electrolytes was conducted. This study led to a ternary mixture of solvents (EC/GBL/MP) in which LiTDI is more dissociated. This new solvent mixture improves both the transport properties and the thermal stability of the LiTDI based electrolyte without compromising its chemical and electrochemical stability. Finally, the new LiTDI in EC/GBL/MP electrolyte was tested in NMC/graphite batteries under normal (C/10 rate and room temperature) and severe (10C rate and temperatures varying from - 20 ° C to 60 °C) operating conditions. The aluminium corrosion problem encountered by LiFSI based electrolytes was taken into account and a LiTDI/LiFSI salt mixture based electrolyte showing promising results was presented. The findings of this thesis show that LiTDI or LiFSI can be used as lithium salts in electrolytes for Li-ion batteries
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Kaplenko, Oleksii. "Studium elektrodových materiálů pro Li-Ion akumulátory pomocí elektronové mikroskopie." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377024.
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The aim of this work is to describe the influence of temperature on the structure and chemical composition of electrode materials for Li-ion accumulators. Theoretical part of this thesis contains described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly Li-ion batteries. Considering various composition of Li-ion batteries, the next subchapters deeply analyzes the most used cathode (with an emphasis on the LiFePO4, LiMn1/3Ni1/3Co1/3O2) and anode materials (with an emphasis on the Li4Ti5O12). The next chapters describe the used analytical methods: electron microscopy, energy dispersion spectroscopy and thermomechanical analysis. The practical part is devoted to the description of the individual experiments and the achieved results.
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Tarhouchi, Ilyas. "Etude des phases Li10MP2S12 (M=Sn, Si) comme électrolyte pour batteries tout-solide massives." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0220/document.
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En remplaçant l’électrolyte liquide par un solide, les batteries tout-solide massivessont souvent considérées comme une solution aux problèmes de sécurité desbatteries Li-ion actuelles. La récente découverte du matériau Li10GeP2S12 destructure dite LGPS présentant une conductivité ionique équivalente à celles desélectrolytes liquides a réactivé ce domaine de recherche.Dans cette optique, nous avons étudié les matériaux Li10MP2S12 (M=Sn, Si) destructure LGPS, au moyen de diverses caractérisations structurales (DRX,RMN du 31P, spectroscopie Mössbauer …), de propriétés de mobilité/conductionionique (RMN du 7Li, spectroscopie d’impédance) et de propriétés électrochimiques(voltammétrie cyclique, cyclage galvanostatique).Les échantillons commerciaux de Li10SnP2S12 contiennent des impuretés et uneincertitude subsiste sur la composition de la phase de structure LGPS. Lamodélisation des déplacements de RMN du 31P a notamment permis de mettre enévidence l’influence des lithium en site octaédrique adjacents. Les mesuresd’impédance suggèrent une réactivité avec le Li métallique et la voltammétrieconfirme que cette phase est très instable à bas potentiel, excluant son utilisation entant que simple électrolyte dans une batterie tout-solide. Nous proposons qu’il puisseêtre utilisé à la fois comme électrolyte et comme matériau de négative.L’étude préliminaire des matériaux au silicium souligne la difficulté d’obtention dematériau pur de structure LGPS, et conduit à la mise en cause du modèle structuraldit thio-LiSICON. Par ailleurs, elle montre là encore l’instabilité de ces matériauxface au lithium métalBy replacing the liquid electrolyte by a solid one, solid state batteries are oftenconsidered as a solution to safety issues in current Li-ion batteries. The recentdiscovery of Li10GeP2S12 with so-called LGPS structure, which exhibits an ionicconductivity equivalent to that of liquid electrolytes, has boosted related researchactivities.In this perspective, we studied the Li10MP2S12 (M=Sn, Si) materials with LGPSstructure, using various methods to characterize the structure (XRD, 31P NMR,Mössbauer spectroscopy …), the ionic mobility/conductivity (7Li NMR, Impedancespectroscopy), and the electrochemical properties (cycling voltammetry,galvanostatic cycling) of the material.Commercially available Li10SnP2S12 batches contain impurities and there remains anambiguity in the actual composition of the LGPS type phase. Modelling of the 31PNMR shifts reveals the effect of lithium in neighboring octahedral sites. Impedencemeasurements suggest reactivity with Li metal, and cyclic voltammetry confirms thatthe material is highly unstable at low potential, which excludes its use as a simpleelectrolyte in solid state batteries. We propose that it might be used both as anelectrolyte and as a negative electrode.The preliminary study on silicon based materials highlights difficulties in obtaining apure LGPS-type compound and questions the real nature of the so-calledthio-LiSICON structural model. Besides, it also shows the instability of thesematerials versus lithium metal
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Hsu, Wei-Jung, and 許維容. "Stability Analysis of Li-ion Battery Charger with Multi-Feedback Loops." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/29295w.
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碩士國立臺灣大學
電機工程學研究所
105
Lithium batteries have recently become popular energy-storage devices for many portable products. There are a variety of control schemes for the charging of such a battery. In this thesis, a specific charging configuration composed of a buck converter with a peak current-loop control and multiple outer feedback-loops control is the focus. In addition, only one feedback compensator network can be used. In the thesis, a detailed analysis of the circuit operating modes throughout a complete charging cycle is given. This analysis leads to eight different feedback paths, depending on the stage/condition of the charging process. Small-signal models are developed for each of the eight configurations. Since only one compensator circuit is used for stabilizing the eight different configurations, a worst case analysis of the uncompensated loop gain transfer functions is necessary. Based on the analysis, a design procedure for the compensation network is developed. Simulations are conducted to verify the small-signal model and the compensator design procedure developed. The results reported in the thesis are primarily part of the evaluation efforts preceding an IC development for such the specific charger.
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Chen, Yu-kuang, and 陳昱光. "Thermal stability of LiCoO2 and LiNi0.8Co0.2O2 cathode for lithium ion battery." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/73875364422666601232.
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碩士國立中央大學
化學工程與材料工程研究所
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LiCoO2 is the most widely used commercial cathode material for LIBs. However, it suffers from severe limitations in cell capacity and safety due to overcharge problems, which occur when the cut-off charge potential exceeds 4.3 volts and metallic lithium can be electrodeposited from the LiCoO2 layer structure. The formation and presence of metallic lithium may create a fire and explosion hazard during extreme use. LiNixCo1-xO2, with its higher capacity, also has safety concerns, although to a lesser extent. In this work, we plan to investigate the cell safety and decomposition mechanism of LiCoO2 and LiNixCo1-xO2 cathode materials, in order to improve related cell performance, by using various coating materials, and to correlate improved performance with cell safety. Our tasks include: (1) studying the thermal runaway mechanism and analyzing the safety of the cathode materials of interest under various charge/discharge conditions or different intercalation/deintercalation conditions; (2) the thermal analysis of the above layer-structure cathode materials when surface treated with mixed metal oxides：LAG coatings under high temperatures, high charge potential or high charge/discharge rate; (3) evaluating the effect of using different mixed metal oxides or coating materials on cell safety.
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Datta, Ujjwal. "Battery Energy Storage System for Renewable Energy Integrated Power System Stability Enhancement." Thesis, 2020. https://vuir.vu.edu.au/41874/.
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With growing environmental concerns and sustainability movements, renewable energy source (RES) penetration is increasing and expected to have a steady growth in the coming years. Power systems have encountered several inherent technical challenges, resulting from either low inertia contribution by the increased RES or the displacement of fossil fuel generation systems within the network. The decreased system inertia and the decline in power reserve capacity are affecting the dynamic and transient stability performance of the power system adversely and this adverse impact will continue to increase due to further RES penetration in electric power systems.
In this context, this thesis contributes new knowledge to the modelling of droop controlled BESS for enhancing damping capability and transient stability of large-scale power networks with different level of RES penetration. The BESS with conventional Proportional Integral (PI), and two new PI-lead and lead-lag controlled BESS with coordinated charge control are given wider attention. In the initial stage, a wind farm is designed to perform frequency control in a microgrid. A sectional droop gain method is adopted for regulating doubly fed induction generation (DFIG) power output. It is observed that the proposed multi-gain droop control method demonstrates superior performance than the conventional approach. However, DFIG has a certain limit of providing under-frequency support as a result of inherent incapability of regulating incoming wind speed. Hence, a more reliable energy source is required to secure the stability of the system.
Realizing these facts, comprehensive simulation studies have been carried out to explore various RES penetration level and dynamic response capability of the system undergoing multiple contingencies. Simulation results demonstrate that generator control and system loading conditions have significant impact on damping capability in primary frequency control. However, results with active power regulated BESS exhibit its effectiveness in enhancing primary frequency controllability of the system regardless of generator control and system loading conditions in power grid as RES penetration increases. Furthermore, a new state of charge (SOC) adaptive charging strategy is proposed for recovering battery SOC to ensure BESS reliability against future contingencies. The new adaptive SOC strategy defines separate levels of SOC charging limit than that of the maximum SOC limit to ensure sufficient SOC excursion for over-frequency events.
In the next stage, a droop controlled BESS is modelled and investigated to control simultaneous voltage and frequency responses of the system by regulating its active and reactive power independently. The performance of BESS is compared with the state- of-the-art technology Static Compensator (STATCOM), while the system is exporting a large amount of power across the network under various contingency studies. It is shown via simulation studies that STATCOM fails to secure voltage and frequency stability of the system in the occurrence of a single or multiple adjacent faults. On the contrary, the incorporated BESS with active and reactive regulating capability remains successful in maintaining the stability of the power system. Also, lead-lag controlled BESS has demonstrated improved performance than PI and PI-lead controlled BESS.
In the final stage of research, the effectiveness of BESS in a charging station is explored to avoid transformer overloading, provide PV smoothing and to increase the charging capacity of the station. Simulation studies showed that BESS can effectively reduce transformer overloading and as a result it prolongs its lifespan and provide grid services when charging station has no load demand.
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Walanda, Daud Karel. "Manganese oxide stability and morphology in sulfuric acid electrolyte." Thesis, 2006. http://hdl.handle.net/1959.13/1405592.
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Research Doctorate - Doctor of Philosophy (PhD)Digestion of Mn₂O₃ and Mn₃O₄ in a range of H₂SO₄ solutions (0.01-10.0 M), at a variety of temperatures (20-140 °C) has led to the formation of a series of kinetically stable manganese dioxide samples via a dissolution-precipitation mechanism involving disproportionation of a soluble Mn(III) intermediate. The resultant manganese dioxide samples were characterised in terms of their domain of phase stability, chemical composition, structure, morphology and electrochemical performance. γ-MnO₂ predominated at all but high H₂SO₄ concentrations (>5 M), where α-MnO₂ was formed, and high temperatures (>80 °C) where β-MnO₂ was formed. The structural variety of γ-MnO₂ in this domain of stability was interpreted in terms of the fraction of De Wolff defects (Pr), which was found to increase as the H₂SO₄ concentration was decreased and the temperature was increased, microtwinning (Tw), which despite being less statistically significant, was found to follow a similar trend, and cation vacancy fraction and Mn(III) fraction. Both the latter structural properties decreased as the temperature was increased; however, decreasing the H₂SO₄ concentration led to a decrease in cation vacancy fraction but an increase in Mn(III) fraction. These structural characteristics, in particular De Wolff defects, were interpreted on a molecular level in terms of soluble Mn(III) intermediate condensation in which the electrolyte conditions determine the relative proportions of equatorial-axial edge sharing (ramsdellite domains only) and equatorial-axial comer sharing (both ramsdellite and pyrolusite domains) that occurs. Morphological differentiation was easily established due to the different characteristics of each phase. γ-MnO₂ existed as fine needles (250 nm x 50 nm), β-MnO₂ was formed as much larger columns (1 μm x 100 nm), while α-MnO₂ was present as small spheres up to 400 nm in diameter. Electrochemical characterisation by voltammetry in an aqueous 9.0 M KOH electrolyte demonstrated that the performance of the γ-MnO₂ samples was comparable to that of commercial EMD, whereas α- and β-MnO₂ suffered from diffusional limitations which lowered their operating voltage. For γ-MnO₂, superior performance resulted when lower temperatures and H₂SO₄ concentrations were used, corresponding to intermediate levels of De Wolff defects and micro twinning, but a cation vacancy fraction minimum. Examination of the kinetics of transformation of Mn₂O₃ into γ-MnO₂ involved two reactions; i.e., Mn₂O₃ disappearance and MnO₂ formation, which were both characterised using an autocatalytic first-order mechanism. In general, the kinetics of Mn₂O₃ disappearance and MnO₂ formation increased as acid concentration and temperature were raised. The kinetic rate of MnO₂ formation is somewhat smaller compared with the Mn₂O₃ disappearance rate, which probably associates with the time needed for nucleation during the induction period. Digestion of LiMn₂O₄ in 0.2 - 7.0 M H₂SO₄ at temperatures ranging from ambient to 120 °C resulted in a number manganese oxides including λ-MnO₂, R-MnO₂, β-MnO₂ and γ-MnOOH. λ-MnO₂ can be regarded as an intermediate species, formed after Li-extraction by acid, leading to other types of manganese oxides upon acid digestion. Morphological examination showed that the particle sizes of the digested products were decreased while maintaining their shape. A kinetic study on this system resulted in a contrary phenomenon compared to the one found in Mn₂O₃ system, in which the disappearance of the starting LiMn₂O₄ materials and R-MnO₂ formation were decreased as acid concentration and temperatures were increased. Digestion of partially reduced EMD and λ-Mn0₂, a general formula HMn₂O₄, in 0.2-7.0 M H₂SO₄ at various temperatures exhibited different mechanisms. Upon acid digestion, the reduced EMD was reverted back to EMD (γ-MnO₂) structure, whilst the reduced λ-MnO₂ was converted into R-MnO₂. The surface morphology of reduced EMD and the product after acid digestion were to some extent similar to EMD; however, the digested product was less compact compared with the reduced EMD. Morphological examination of reduced λ-MnO₂ showed it was different when compared to the λ-MnO₂. The sample has an interior of compact column/tube-shaped agglomerates covered loosely by column-shaped particles. After acid digestion both resultant samples were found to be needle-like particles of various lengths.
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Lu, Jun Feng, and 呂俊鋒. "Dynamic modelling of battery energy storage system and application in power system stability." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/76937563291364742764.
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Jane, Cheng-Xiang, and 簡丞庠. "Use of battery energy storage to maintain the stability of the wind farm." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50817605500498638469.
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碩士東南科技大學
電機工程研究所
103
Due to the uncertainty of renewable energy generation, making limited use of renewable energy sources, this paper regenerative power systems use batteries to improve the situation. Significant economic growth in recent decades and the industry, the chemical fuel consumption has been greatly increased. It will lead to many environmental problems concentrated, particularly in the global warming problem. For this fuel shortage, many countries are studying how to solve these problems. The natural resource wind power is considered to be a clean (no emissions) and free of fuel costs, it is one of the best alternatives to power generation. In wind speed causes the generated output power fluctuations uncertainty can install battery to compensate for wind power generation system, you must use the appropriate battery capacity in order to cope with this problem. This thesis analyzes the situation as a short-term energy storage battery, and finally, a battery based energy storage, wind power is added to the system to maintain the stability of the wind power generation system. In this thesis, the use of PSS/E built-in battery energy storage systems on the offpeak power system of Taiwan power company in 2013 , through simulated wind power system fluctuations, added battery energy storage to implement. Simulation results show that wind turbines with the battery energy storage system can improve the stability of wind farm output power. The wind farm output power for a given value, do not change due to wind speed change.
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CHEN, GUAN-TING, and 陳冠廷. "Thermal Stability Analysis on Modified Electrolyte of Lithium-ion Battery Within Different Additives." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/v53wz8.
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碩士國立雲林科技大學
環境與安全衛生工程系
107
Under the rapid advancement of technology and the coming of wireless generation, lithium-ion batteries (LIBs) has been an important carrier for energy storage. LIBs have been loved by people owing to excellent working voltage, longer cycle life, dexterity, and carry easily. However, it is complicated have that the chemical reaction of LIB process in which the electrolyte takes an important role. Through the electrolyte, lithium-ion was freed to generate the electric charge and formed solid electrolyte interface (SEI) on the anode. To increase the used efficiency of the battery, the LIBs of the commercially available were modified by adding a minor amount of additive. This study will analyze the thermal stability of electrolyte with the additive that we used the commonly used such as benzotriazole (BzTz). The experiment was also carried out through the different state of capacity (SOC) of ternary cathode material, LiNiCoMnO2 (NCM). As the results of DSC that the LiPF6 decomposed occurred at 180 °C, we can be aware that the pressure rising of LiPF6 within BzTz was slower than LiPF6 electrolyte. The maximum pressure of LiPF6 with and without BzTz was 384.3 and 247.3 psig, respectively. The second pressure rising caused by the decomposition reactions of various organic carbonates which was initiated by the decomposition of LiPF6.
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陳俊昌. "Static Var Compensator and Battery Energy Storage System for Shipboard Electirc Power System Stability." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/80152075190708545361.
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碩士國立海洋大學
電機工程學系
90
The shipboard electric power system is an independent system of which the required reliability is higher than that of the seashore power system. Because of the frequent load variation, the generating unit shall have fast and stable response. Equipped with properly tuned additional Static Var Compensator will improve the damping of electromechanical oscillations in power system. Battery Energy storage system can provide simultaneously control of both its active and reactive power to improve power system operation and control. The main purpose of this thesis is to study the stability of the shipboard electric power system on analyzing the effect of the Static Var Compensator and Battery Energy Storage System on overall system dynamic behaviors. A sample shipboard electric power system is taken as the study system. Based on the results analyzed and verified from the time-domain simulations, this paper shows that Battery Energy Storage System and Static Var Compensator can offer an important resource for improving shipboard electric power system operation.
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CHENG, MENG-HUAN, and 鄭孟桓. "Using Rotating Ring-Disk Electrode to Study the Stability of Organic Solvents in Li-O2 Battery Electrolytes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/14204751332752515397.
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碩士國立高雄大學
應用化學系碩士班
105
Lithium-Oxygen Battery (Li-O2 battery) is attractive due to its huge theoretical energy density (~11000 W/hr), but there are still some obstacles to be overcome. One of the problems is that the electrolyte is not stable and may decompose during discharging/charging process. To realize and to solve this problem, we use rotating ring disk electrode voltammetry (RRDEs) to study the reactions and to quantify the stability of the electrolyte by calculating the oxygen reaction rate constant(kf) and the electrolyte decomposition rate constant(k). Our results confirm that acetonitrile(MeCN) gets the highest kf(7.78×10-2 cms-1), which means the oxygen reduction reaction is the most easily to work in this electrolyte. Pyr14TFSI(1-Butyl-1- methylpyrrolidinium bis(trifluoromethylsulfonyl)imide)has the smallest kf due to its high viscosity and low oxygen diffusion ability. At the other hand, Pyr14TFSI has the lowest decomposition rate constants, means this electrolyte has the best stability against superoxide.
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Chinnapaiyan, Sathishkumar, and Sathishkumar Chinnapaiyan. "BUFFER LAYER COATING TO STABILIZE ELECTRODE/ELECROLYTE INTERFACE FOR SOLID STATE LI-ION BATTERY." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/x9tym2.
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碩士國立臺北科技大學
機械與自動化碩士外國學生專班
107
The present petroleum product based vitality economy is confronting genuine challenges because of the consistent increment in oil request and the exhaustion of non-sustainable assets. The production of electrochemical energy is an alternative energy source. Li-ion batteries and fuel cells are presently the leading energy storage devices in electronic vehicles. Current lithium-ion batteries are usually built on a liquid electrolyte that can cause leakage and may be explosions. Thus all-solid-state batteries, which uses a solid electrolyte in its place of liquid electrolyte, are considered to be a source of next-generation power. In this study, Sodium(Na) Super Ionic CONductor (NASICON) type Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid electrolyte is synthesized by melt quench method. The LAGP glass sheet is crystallized at 800°C for 8 hours with the ionic conductivity and the activation energy as 2.3×10-4 S/cm and 0.23 eV, respectively. Atomic layer deposition (ALD) of Al2O3 thin film is used to reduce the interfacial resistance between LAGP and Li metal. The interfacial resistance is minimized from 6357 Ω cm2 to 1903 Ω cm2 due to the coating of Al2O3 (4 nm) on LAGP. Compared to bare LAGP, ALD of Al2O3 coated LAGP has a stable cycling behavior with a minimal voltage difference for 16 hours, as well as a lower resistance. These results recommend that ALD of Al2O3 coating is effective in enhancing the stability of the LAGP/Li interface.
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Hsiao, Hsuan-Hai, and 蕭炫海. "Thermal Stability and Charge-Discharge Behavior of Sputter Deposited Spinel Lithium Manganese Oxide as Positive Electrodes for Thin Film Battery." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/cu2ny2.
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碩士逢甲大學
材料科學所
91
Lithium ion secondary batteries have recently received extensive attention to be used as a portable energy source, particularly, for lightweight, compact 3C electronics, owing to their high and stable working voltage, superior energy density, low self-discharge rate, and long shelf life. Motivated by this fact, this work examines the features of sputter deposited lithium manganese oxides (LiMn2O4) thin films as battery’s cathode material Thin films of the spinel compounds were deposited by rf magnetron sputtering of LiMn2O4 target on silicon substrates under two conditions: (1) low sputtering Ar pressure (0.4 Pa) without intentionally heating the substrate (denoted as LPLT) and (2) high sputtering Ar pressure (2 Pa) with substrate held at 300℃ (denoted as HPHT). The physical properties (microstructure, phase distribution, composition, bonding…etc.) of the two types of films, subsequently after high-temperature (300□700℃) annealing, were studied using glazing incidence X-ray diffraction (GIXRD), transmission electron microscope (TEM), X-ray absorption near edge structure (XANES) and Raman spectroscopy. Analyses of TEM confirm that LPLT thin film is slightly over-stoichiometric (Li1+0.147Mn2O4) and contains only a single-phase (cubic spinel). The grain size of the as-deposited thin film is about 50 nm. The microstructure of the single-phase LPLT-Li1+0.147Mn2O4 thin film is very unstable. Thus, annealing at temperatures in the range from 500 ℃ to 700 ℃ gradually induces a two-step decomposing process of the following nominal reaction formula: (1) LiMn2O4 ，□ Li2Mn2O4 → MnO1.88; (2) Li2Mn2O4 → LiMnO2 + α-MnO2. Conversely, two phases (LiMn2O4 and α-MnO2) coexist in the HPHT thin film which is slightly under-stoichiometric and has an overall composition as Li1□0.147Mn2O4. The HPHT-film comprises ultrafine (~5 nm), equiaxed Li1Mn2O4 grains embedded in amorphous-like α-MnO2. The HPHT-film is very stable and thus can maintain the original phases and microstructure even after annealing at 700℃. Results of X-ray absorption and Raman spectroscopic indicate that the HPHT-film indeed is far more stable than the LPLT-film, correlating with results made by TEM. Cycling the batteries electrochemically shows that the HPHT-film outperforms the LPLT-film in terms of working voltage and capacity, also attributed to differences in stability of the phase/microstructure between the two types of films.
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Kim, Hyun Woo. "Structure and properties of amorphous metallic alloys : a first principles study." Thesis, 2010. http://hdl.handle.net/2152/ETD-UT-2010-12-2328.
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Utilization of amorphous metallic alloy has received much attention for use in numerous microelectronic and electrochemical devices since they provide unique electrical, thermal conductivity, and magnetic properties. To develop these functional properties, it is essential to understand the amorphous structure and the property relationships. First principles calculations provide insight into the structure, thermodynamic stability, electronic and magnetic properties of amorphous alloys. For Ru- and Co-based alloys, the thermodynamic stability was examined by calculating the mixing energy along with those of crystalline counterparts. The amorphous RuP, CoP, RuB, and CoB alloys, become energetically more favorable than their crystalline counterparts at moderate P(B) content. The atomistic structures have well-defined local structures depending on the atomic size ratio and electronic interactions between constituent elements. Their local ordering is attributed to strong p-d hybridization, which contributes to stabilizing the Ru(Co)-P(B) alloys. Surface segregation of P(B) and interfacial adhesion with copper were also studied. Li-X (X: Si, Ge, and Sn) were examined when 1 or 2 Li atoms are inserted into the interstitial sites. Li insertion in the tetrahedral site, which is the most preferable site in the diamond matrix, causes outward displacement and charge localization around the X neighbors, thereby weakening of the covalent bonds leading to destabilization of the host matrix. We present the energetics, structure, electronic and mechanical properties of crystalline and amorphous Li-X (X: Si, Ge, Sn, and Si+Sn) alloys. Our calculations show that the incorporation of Li leads to disintegration of the tetrahedrally-bonded X network into small clusters of various shapes. Electronic structure analysis highlights that the charge transfer leads to weakening or breaking of X bonds with the growing splitting between s and p states, and consequently the Li-X alloys softens with increasing Li content.text
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Wu, Meng. "Fuzzy-Rule-Based Failure Detection and Early Warning System for Lithium-ion Battery." 2013. http://hdl.handle.net/1805/3522.
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Indiana University-Purdue University Indianapolis (IUPUI)Lithium-ion battery is one kind of rechargeable battery, and also renewable, sustainable and portable. With the merits of high density, slow loss of charge when spare and no memory effect, lithium-ion battery is widely used in portable electronics and hybrid vehicles. Apart from its advantages, safety is a major concern for Lithium-ion batteries due to devastating incidents with laptop and cell phone batteries. Overcharge and over-discharge are two of the most common electrical abuses a lithium-ion battery suffers. In this thesis, a fuzzy-rule-based system is proposed to detect the over-charge and over-discharge failure in early time. The preliminary results for the failure signatures of overcharged and over-discharged lithium-ion are listed based on the experimental results under both room temperature and high temperature. A fuzzy-rule-based model utilizing these failure signatures is developed and validated. For over-charge case, the abnormal increase of the surface temperature and decrease of the voltage are captured. While for over discharge case, unusual temperature increase during overcharge phases and abnormal current decrease during overcharge phases are obtained. The inference engine for fuzzy-rule-based system is designed based on these failure signatures. An early warning signal will be given by this algorithm before the failure occurs. This failure detection and early warning system is verified to be effective through experimental validation. In the validation test, the proposed methods are successfully implemented in a real-time system for failure detection and early warning. The result of validation is compatible with the design expectation. Finally an accurate failure detection and early warning system is built and tested successfully.
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CHANG, WEI-LUN, and 張瑋倫. "Chiang Kai-shek’s Off-Shore Islands Strategy and its Contribution to Taiwan’s Safety and Stability in the light of the 823 Battle." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/6e63h7.
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碩士國防大學政治作戰學院
政治研究所
102
In recent decades, Kinmen, Matsu and other offshore islands experienced a number of key battles, and suffered numerous heavy artillery attack. Isolated on the other side of the Taiwan Strait, Kinmen and Matsu islands not only embody the indomitable spirit of the “lonely island people are not alone,”but as the defender of peace in the Taiwan Strait have a profound impact on all of us. Before and after the central government moved to Taiwan, as a result of international realities, the United States on several occasions questioned the strategic value of the outlying islands. Under PRC’s increasingly aggressive attempts to invade these islands, Chiang Kai-shek as President of the ROC paid repeated visits to Kinmen Battlefield defense, and gave guidance in political, economic, cultural and social construction on the island, leading to its recovery from previous poor conditions. In July 1958 , PRC’s navy, air force and artillery units began to build up in Fujian, a visible clue that communists planned on invading Kinmen and Matsu islands. On July 29, the 823 Battle kicked off, but with Chiang Kai-shek’s military strategic guidance and our soldiers’heroic struggle, communists failed to achieve their objectives but they kept shelling those islands intermittently for two decades and stopped doing so after they established diplomatic relations with the United States in 1979. Today, Taiwan’s economic prosperity and democracy are recognized by the international community . As time goes by, the 823 Battle has gradually become history, but we should bear in mind that “when a bird's nest is overturned, no egg can remain intact.” We are thankful to those who sacrificed their lives to keep those islands intact. In this context,this study intends to prove the importance of those islands and demonstrate Chiang Kai-shek’s contribution to Taiwan for his insistence on keeping and building Kinmen and Matsu.
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CHAUVIN, Christophe. "Utilisation d'anions à fonction sulfate dans des électrolytes pour batterie au lithium. Etude des mécanismes de transport." Phd thesis, 2005. http://tel.archives-ouvertes.fr/tel-00009490.
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Des sels de lithium à base d'oligoéther sulfate ont été synthétisés et caractérisés. Ils intègrent des motifs oxyéthylènes qui permettent une solvatation du cation lithium et, potentiellement, une utilisation en tant que liquide ionique. Leurs propriétés en tant que sels dissous dans des solvants liquides ou polymères ont été évaluées. Leurs domaines de stabilité thermique et électrochimique sont suffisants. Du fait de leur faible dissociation en milieu poly(oxyéthylène), leurs conductivités sont faibles. Par contre, ils présentent des nombres de transport cationique élevés. En mélange avec des sels comme LiTFSi, ils permettent d'atteindre un excellent compromis conductivité/nombre de transport cationique/coût. Le second volet de l'étude concerne la synthèse et la caractérisation d'un polyélectrolyte à fonctions ioniques sulfate de lithium et à squelette polyéther. Les caractérisations physico-chimiques et électrochimiques ont montré qu'il pouvait être utilisé comme électrolyte polymère. Son potentiel sous forme de polymère réticulé et gélifié est remarquable. Des analyses structurales faites sur un monocristal d'ionomère ont pu être corroborés par des calculs de mécanique quantique.
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Carter, W. Craig. "Computation and Simulation of the Effect of Microstructures on Material Properties." 2002. http://hdl.handle.net/1721.1/3970.
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Methods for and computed results of including the physics and spatial attributes of microstructures are presented for a number of materials applications in devices. The research in our group includes applications of computation of macroscopic response of material microstructures, the development of methods for calculating microstructural evolution, and the morphological stability of structures. In this review, research highlights are presented for particular methods for computing the response in: 1) ferroelectric materials for actuator devices; 2) coarse-graining of atomistic data for simulations of microstructural evolution during processing; 3) periodic and non-periodic photonic composites; and 4) re-chargeable battery microstructures.Singapore-MIT Alliance (SMA)