Pure Lithium Research Articles

Boron extraction using selective ion exchange resins enables effective magnesium recovery from lithium rich brines with minimal lithium loss

• Li + loss decreases from 13.7 to 1.4% during Mg(OH) 2 precipitation in the absence of boron. • Chemical-grade Mg(OH) 2 precipitation was possible from brines free of B. • Amberlite IRA743 resin selectivity extract boron from raw Li reach brines. • Resin saturated with boron can be regenerated and reused with the same efficiency. • The high water intake in the presence of B is associated with hydroboracite formation. Magnesium hydroxide is a commodity chemical, produced in almost pure form from seawater through precipitation. Even though Li brines contain high concentrations of Mg 2+ cations, the precipitation of Mg(OH) 2 from them is not common. Rather it is typically coprecipitated with other salts and becomes a waste. The crystallization of chemical-grade Mg(OH) 2 from a Li + rich brine that contained 3.1 g/L Mg 2+ and 1.3 g/L Li + , was investigated by means of NaOH and CaO addition. Direct precipitation of Mg(OH) 2 leads to considerable Li loss and impure crystals due to the brine uptake into the crystal cake. In order to increase the sedimentation rate and decrease the brine loss, a boron extraction step was introduced, which consisted of initial polishing using Amberlite IRA743. It was possible to extract B to below the ICP detection limit from native salt lake brines selectively and regenerate the ion exchangers for repetitive cycles. Upon the extraction of boron, the Mg(OH) 2 sedimentation rate, increased while the loss of Li + from the brine decreased from 13.7 ± 1.2 to 1.5 ± 0.4%. Precipitation with CaO as an alkalizing agent generated a mixture of crystals and a Li + loss between 6.7 ± 0.8 and 3.8 ± 0.7%. When the boron-free brine was alkalized by NaOH, an increase in the degree of crystallinity of Mg(OH) 2 crystal structure was verified by XRD and a purity of 95 ± 2% for the solid was obtained. The high water intake in the presence of B was associated with the presence of hydroboracite in intercalation within the brucite. It was expected that, if the hydroboracite was present as an intercalation, this structure would be disrupted more easily by the ultrasound, potentially resulting in a loss of the hydroboracite d-spacings. Concluding, subsequent B and Mg removal steps from Li + rich brines result in the production of 95% pure Mg(OH) 2 leaving a brine for high purity lithium salt precipitation, thereby bringing a second attractive product from brine processing.

Nickel recovery from precipitate of NCA lithium-ion battery leach liquor by using disodium ethylene diamine tetraacetate

The nickel cobalt aluminium oxides (NCA) type Li-ion battery is a type of battery currently used in electric vehicles. The UGM battery team has recycled this type of battery to obtain high purity lithium metal. Aside from lithium, the NCA battery contains high-value metals, nickel is one of them. This experiment aims to test the ease of nickel to chelate with disodium ethylene diamine tetraacetate (EDTA). The experiment was carried out by means of a triple neck flask for 4 hours. The samples were taken at certain minutes and then fitted using a pseudo homogeneous first-order reaction equation. The chelate formed was further processed through multilevel precipitation or electrodialysis to separate nickel. Based on the experiment, nickel formed chelates optimally at 60°C using 0.086 M EDTA with the reaction constant for nickel being 1.4819 min−1. The Arrhenius constant and activation energy for nickel were 3.48×1011min−1 and 76,907 J/mole, respectively.

Interphase Control for Electrodeposition of Thin Lithium Films for Lithium Metal Batteries

Rechargeable lithium metal batteries including Li-S batteries, need a thin lithium anode with high purity for high energy density and long cycle life. Today, lithium metal is typically produced from Li2CO3. In contrast to the price of Li2CO3, which is often used for benchmarking, pure lithium metal is actually a costly component. In addition, it has quite some CO2 footprint as it needs significant amounts of energy to produce. Lithium foils of few hundred micron thick are produced by lithium extrusion and cold rolling. To limit cost and to increase energy density, maximum only a few tens of microns is. However, due to the soft nature of lithium, foils of few tens of micrometers are very difficult to manufacture at large volumes and too expensive for cost competitive high energy density Li-metal based cells. Hence, the production of thin lithium foils is currently a bottleneck.The electrodeposition of thin lithium films directly on copper current collector foils could be a cost effective and elegant method, where it not for the high reactivity of lithium with the electrolyte solution and the poor control of lithium morphology. Recently, several approaches have been pursued on lithium electrodeposition by stabilizing the lithium metal-electrolyte interface with the use of solid electrolytes and polymer coatings on electrode [1], however a poor quality of solid electrolyte interphase (SEI) and lithium metal deposition remain as a challenge.Among the various solid-state electrolytes, nitrogen doped lithium phosphate glass or LiPON has been evaluated as solid-electrolyte coatings on electrode particles as buffer layer between active material and the bulk electrolyte [2]. Previously, we investigated the stability of 100 nm down to 10 nm LiPON thin-films as artificial solid-electrolyte interphase for lithium plating and stripping on copper current collectors. We demonstrated the reversible plating/stripping of 150 nm lithium layer for over 100 cycles, indicating formation of a uniform lithium metal layer in-between substrate and LiPON layer [3].In the present work, we further investigated the effect of artificial solid electrolyte interphase, such as LiPON and poly(ethylene) glycol (PEG) coatings, on the deposition behavior of lithium to fabricate micro-meter thick lithium layer which is desirable for negative electrode in next-generation battery application. With a thin LiPON (<150 nm) layer, lithium layer uniformly grew up to 1 μm between substrate and LiPON without breaking of LiPON layer. However, the breakage of the thin LiPON layer was observed with further growth of lithium layer leading to dendrite growth. On the other hand, with a thick PEG coating (> 1 μm) dendrite growth was mitigated by increasing the molar mass of PEG from 8000 to 600,000 g/mol. Furthermore, addition of PEG into the carbonate-based electrolyte resulted in a denser lithium film with a thickness of 2-5 μm without dendrites. In the presentation, effect of molar mass, concentration of PEG on growth behavior of lithium will be further discussed.

Electrolytic Recovery of Lithium from Used Li-Ion Battery Material Leachate through a CO2-Negative Process

Lithium materials are attracting attention from industrial and research institutes in recent decades.[1-3] The demand of lithium battery materials is growing due to applications in Li-ion batteries for portable devices, electric-vehicles, and energy storage. In 2016, around 78,000 metric tons of lithium carbonate (equivalent) was consumed, much higher than that in 2010 at 29,000 metric tons, and the statistics forecasted a global demand reaching 509,000 metric tons by the year 2025.[4] Though the increasing consumption of Li2CO3 opens a big market, the producers were still limited, mostly due to high manufacture cost for high purity lithium carbonate. In recent studies, researchers focused on electrolytic extraction of lithium from salt-lake brines and seawater [5, 6], and solvent extraction using organic solvents such as DEHPA/kerosene [7]. These methods were applicable in producing lithium species, but the drawbacks included large amounts of chemical additions and waste generations.In our study, lithium has been electrochemically recovered in a form of Li2CO3, as the last step in separating critical metals from shredded battery materials. This work is part of a larger effort to recover critical elements from Li ion batteries. Other efforts in the project include shredding of used batteries, leaching critical metals from shredded battery materials, and separating Ni and Co from the leachate. The elution from Ni and Co extraction will be used as the anolyte in the electrolytic cell, containing primarily Li and Mn.Aiming at recovering lithium from the elution in a green pathway, we introduced an electrochemical process consuming only the produced Li-rich elution and CO2. In the recovery process, the anolyte was the elution, and the catholyte was a CO2-captured solution. Electrolytic studies were carried out through chronoamperometry and chronopotentiometry measurements. Li2CO3 could be collected as a precipitate product with a 100% purity analyzed with atomic adsorption spectroscopy and X-ray diffraction. After each experiment, the catholyte could be simply recovered by bubbling CO2, and the recovered catholyte has been proved to be effective for multiple uses.The electrochemical method used in this study has been proved to be feasible for the purpose of separating and recovering lithium as a Li ion battery material. In this lithium recovery process, CO2 is captured and solidified. As the only reagent consumed in the process, CO2 can be sourced from air and waste emissions from burning of fossil fuels. Instead of adding additional chemicals such as LiCl [8] and Na2CO3 [9] to catholyte to accelerate lithium extraction and precipitation in literatures, Li ions are directly converted into ultrahigh purity Li2CO3 precipitates in this work.

Crystallization of the glasses within the SiO2-Li2O-TiO2 system

Glasses from the ternary system SiO2-Li2O-TiO2 with increasing titania content replacing silica were prepared by melting-annealing technique. Structural FTIR, thermal and differential thermal analysis (DTA) properties of the glasses were measured and evaluated. X-ray diffraction and scanning electron microscope investigations were done to identify the crystalline phases formed together with revealing their morphological features. The coefficient of thermal expansion (CTE) data of glass-ceramic samples are identified to be between 80.83 × 10−7 °C−1 and 120.04 × 10−7 °C−1 (23–500 °C). The increase of the CTE is assumed to be concomitant with the increase of the crystallization of lithium metasilicate (Li2SiO3) phase or quartz (SiO2). Titania is assumed to behave primarily partly as a modifier oxide and at high titania content; it is assumed to act as former (TiO4) groups. X-ray diffraction patterns indicate that the pure lithium silicate glass produces lithium disilicate (LS2) and quartz (SiO2) as crystalline phases and with increasing TiO2, first it acts as a nucleating agent initiating the formation of different crystalline silica phases beside (LS2) then titania is separated at 15 %TiO2 and 30%TiO2 as lithium titanate. The microhardness and densities values are calculated. The studied samples show promising thermal and mechanical properties especially for both CTE and microhardness values, beside their chemical stability which could be applied for commercial uses.

Defects and Some Physical Properties of Nominally Pure and Zinc-Doped Lithium Niobate Crystals

Defects and Some Physical Properties of Nominally Pure and Zinc-Doped Lithium Niobate Crystals

A closed-loop process for selective lithium recovery from brines via electrochemical and precipitation

With the growing demand for lithium from electric vehicles, efficient recovery of lithium from brines is attracting more attention. However, it is difficult to produce high purity lithium carbonate (Li2CO3) from brine in a rapid and energy-efficient manner. In this work, a closed-loop process was developed to recover lithium from brine and produce high-purity Li2CO3. The lithium in the brine was first selectively recovered by Electrochemical Deintercalation/Intercalation system (EDIs), and then a high concentration of lithium solution was obtained by precipitation, which replaced the traditional time-consuming evaporation process. The lithium yield of each step was above 87%, and the purity of Li2CO3 reached the battery-grade standard after three times washing. In addition, the Fe3+ and PO43- used in the process can be reused, and basically no waste residue was generated. This research has potential applications in the rapid concentration of low Li+ concentration solution obtained from brine and the preparation of high purity Li2CO3.

Precise determination of 6Li/7Li isotopic ratio with NaLiBO2+ ion using total evaporation and ion integration by Thermal Ionization Mass Spectrometry(TIMS)

Total Evaporation and Ion Integration technique (TE & II) was used for determination of the 6Li/7Li isotope ratio with the NaLiBO2+ (m/z 71–73) and Na2BO2+ (m/z 88, 89) molecular ions emitted from the sodium lithium borate compound on the single filament assembly. Since the ion intensities are simultaneously collected by the multi-collector assembly and integrated till the sample is completely consumed, the measured ion intensity ratio 72I/73I is less affected by fractionation and hence closer to the true value. The fractionation profile for lithium isotopes showed concurrence with the Rayleigh's distillation law since the measured instantaneous ratio of 72I/73I at ∼63% sample consumption was equal to the integrated value at 100% sample consumption. The minimum sample size requirement for molecular ion method decreased to 50 ng of lithium for the TE method of data acquisition compared to 1–2 μg of lithium required for conventional method of limited scans. The relative standard deviation of 6Li/7Li ratio determined from the analyses of six samples of 500 ng each of the two natural Li2CO3 samples namely L-SVEC and high purity Spec-pure lithium was about 0.05% (1σ). Refractory materials Li2TiO3 and LiAlO2 were also successfully analysed by the developed TE method with reduced sample size. The TE method enhanced the benefits of the molecular ion method by further decreasing the effect of fractionation as well as sample size requirement for accurate determination of 6Li/7Li ratio. The method could clearly distinguish between the two natural lithium samples, L-SVEC lithium and Spec pure lithium having a difference of 0.5% in their 6Li/7Li ratio.

Substitutional Lithium Doping on Germanene: A First-principles Study

The density functional theory (DFT) based first-principles calculations have been adopted for the study of structural, electronic and magnetic properties of pure and single Lithium (Li) atom doped germanene monolayer. Due to the higher intrinsic carrier mobilities and large spin orbit gap, germanene has great possibility of being integrated into the silicon based semiconductor industry. Different studies have been done to change the band gap value from its’ pristine zero band gap state. We have doped the single Li atom into the germanene system with the intention of tuning the band gap and other electronic and magnetic properties. Band structure calculations show pristine germanene is semi-metallic in nature whereas the Li doped system is fully metallic with the overlapping of the conduction and valance bands in the Fermi level. Under density of states (DOS) calculations, it is evident that both pristine and doped system are non-magnetic in nature with symmetric DOS plot.

Concurrent magnesium and boron extraction from natural lithium brine and its optimization by response surface methodology

The high demand of lithium for electromobility and energy storage requires an efficient and sustainable optimization of the current extraction from natural lithium brine process. In this context, this study develops a simultaneous Mg2+ and B3+ extraction system, which could be a contribution to the elimination of precipitation stages and the generation of high purity lithium brine. This dual system composed of a dialkylphosphate ionic liquid and a 2-ethylhexanol/kerosene mixture as magnesium and boron extractors, respectively, was optimized by a mathematical and statistical method known as response surface methodology (RSM). The RSM method identified, through a small number of experiments, the interdependencies of the parameters involved in the extraction process, and calculated their optimal values to achieve the maximum extraction efficiency of Mg2+ and B3+. The optimization was performed from two approaches. The first, maximizing the extraction of Mg2+ and B3+, resulted in experimental efficiencies of 99.17% of Mg2+, 99.36% of B3+ and 23.54% of Li+; whereas the second, in which lithium co-extraction was minimized, yielded efficiencies of 83.56% Mg2+, 99.22% B3+ and 3.36% Li+, results that demonstrate the high extraction capacity of the system, as well as proving the validity of the statistical model.

A continuum PNP model of double species ion transport between graphene

In this paper, we employ Poisson–Nernst–Planck equations in conjunction with the Navier–Stokes equations and the mean-field theory to investigate the charge transport of double species monovalent ions in double-layered graphene sheets, driven by an external electric field. Unlike most classical models, we develop a simple mechanical model by incorporating the microscopic effects of the physical systems so that the ionic interactions between ions and the host material, and the steric repulsions among ions are considered. Taking Li+-PF6−1 monovalent ions as an example, we find that the transport pattern for the present double species ionic systems and that for the pure lithium ions are dramatically different. Due to the mutual attractive ionic forces between ions and their counter-ions, such double species systems turn out to be more stable than that of the single species systems. In addition, the storage patterns of the former systems are richer, which depend heavily on initial ionic states, however less on the strength of applied electric fields and external temperatures when the graphene separation is not too large. The fluid flows, the electric conductivities and the stability of such double species systems are subsequently scrutinized. The current study could form a theoretical basis to help designing high-performance lithium batteries and explaining ion transport in biological channels.

In‐plane Defect Engineering Enabling Ultra‐stable Graphene Paper‐based Hosts for Lithium Metal Anodes

AbstractGraphene papers are widely studied as stable hosts to suppress lithium dendrite growth and accommodate the volumetric expansion for lithium metal anodes. Designing and constructing flexible graphene‐based films with unique structures as stable hosts in large scales for lithium metal anodes is challenging in terms of their realistic applications. Herein, scalable three‐dimensional (3D) holey reduced graphene oxide (HrGO) films with abundant as‐tailored oxygen functional groups on hole defects of graphene nanosheets are successfully constructed as stable hosts for lithium metal anodes. The as‐designed anodes deliver a stable voltage of 11 mV for 1900 h at a current density of 0.2 mA cm−2. The achieved cycling times of the optimized Li‐HrGO‐4 film anodes are over 1000 and 800 h at current densities of 0.5 and 1.0 mA cm−2, respectively. Simultaneously, the Li‐HrGO‐4 composite film anodes also exhibit superior rate performance as compared to pure lithium and Li‐rGO film anodes when utilized in symmetric cells. The as‐assembled LiFePO4/Li‐HrGO‐4 full cells show superior rate performance and retain capacity after 300 cycles at the rate of 1 C. Furthermore, first‐principles calculations indicate that C−O and O−C=O groups on defects of HrGO surfaces lead to excellent lithium affinity and uniform deposition. Above all, the unique 3D holey structure with as‐tailored oxygen defects and its design strategy holds a significant potential for the development of high energy‐dense and stable metal batteries.

Performance of a double-slope solar still for the concentration of lithium rich brines with concomitant fresh water recovery

Lithium recovery from brines has become a hot topic. The current evaporitic technology is slow, and serious environmental concern has been raised regarding the large volumes of water used, relating both to brine concentration through evaporation, and intensive pumping of fresh water needed in the fine chemical processing to produce high purity lithium carbonate.In this work, an experimental and theoretical analysis of brine desalination using a double-slope Solar Still was carried out. The Solar Still was installed right next to an existing lithium mining facility in northwest Argentina, and was tested with native high salinity lithium rich brine for a continuous year under the typical weather conditions of lithium deposits: high altitude, large thermal amplitude between day and night, strong winds, and high solar radiation. The performance of the solar still as an evaporator was compared with that of a PAN evaporimeter class A, and correlated to experimentally determined weather parameters. While the performance of the Solar Still for brine concentration was below that of open air evaporation, the Solar Still allowed for the production of an average of 2 L day−1 m−2 of distilled water, in marked contrast with current practice. Numerical simulations allowed us to quantify heat exchanges in both the Solar Still and the open air system.

Importance of Interlayers on Li Solid-State Batteries Using Ceramic Electrolytes

Recently, all solid-state Li ion batteries have received great attention due to its better safety feature. Among several types of inorganic solid electrolyte, Garnet-structured Li6.5La3Zr1.5Ta0.5O12 (LLZTO) is found to exhibit high ionic conductivity with adequate stability especially directly connecting to pure lithium foil as anode. However, it is difficult for inorganic solid electrolyte to have full contact with lithium anode, the high interface polarization and poor wetting ability between solid electrolyte and anode has been a major concern in all state Li ion batteries. Therefore, interface engineering between solid electrolyte and electrodes has been shown to exhibit low interface polarization. In this study, the objective is to investigate the effects of metallic interlayer on reduction of the surface polarization between LLZTO and Li using thin film gold (Au) interlayer. The surface impedance has reduced to less 200ohm/cm2which was demonstrated by EIS measurement and Li stripping/plating tests using a symmetrical cell. The battery behavior was observed by LiCoO2/Ta-LLZO/Li battery, which discharge capacity > 125mAh/g for the first cycle.

Optimization of Magnesium-Doped Lithium Metal Anode for Lithium Metal Batteries: Simulation and Experiment

To further improve the energy density of the current lithium ion batteries, tremendous effort has been made on the development of anode materials with higher capacities than the widely commercialized graphite. Lithium metal is considered as the most attractive anode candidate for lithium batteries because of its ultrahigh specific capacity (3860 mAh g-1) and extremely low redox potential (-3.040 V vs. standard hydrogen electrode). While the uncontrolled lithium dendrite growth and the interfacial instability, leading to low Coulombic efficiency, are two big problems for pure lithium metal anodes. Lithium-magnesium alloy has been considered as a potential alternative anode material. There have been some studies of magnesium amount on lithium-magnesium alloy anode with a wide range. It is found that even a marginal amount of magnesium can improve the battery performance. However, the optimum content of magnesium in lithium-magnesium alloy anode and the mechanism on cell performance are still not well understood. Quantum chemistry and molecular dynamics simulation methods have been widely used in advanced electrode materials design to accelerate the material discovery and development. Computational and experimental approaches are combined to optimize the amount of magnesium in lithium-magnesium alloy anode materials and investigate the cell performance. This work focuses on lithium-magnesium alloy with limited magnesium amount. The density functional theory calculation is employed to investigate the effect of doping magnesium amount in lithium-magnesium alloy anode. Simulation results show that the additional magnesium atom in lithium-magnesium alloy can control the plating/stripping of lithium atoms on the alloy anode surface. Moreover, an optimum ratio of magnesium in lithium-magnesium alloy is found when calculating the absorption energy of lithium atom on lithium-magnesium alloy surface. Electrochemical experiments further demonstrate that the alloy anode material with the optimal ratio of magnesium exhibits the best cycling stability in lithium metal batteries with high nickel layered oxide cathode. This work provides an effective approach to identify optimal alloying-type lithium metal anodes for improving long-term cycling stability of high-energy-density lithium metal batteries. More details will be discussed at the presentation.

Boron Influence on Defect Structure and Properties of Lithium Niobate Crystals

Defect structure of nominally pure lithium niobate crystals grown from a boron doped charge have been studied by Raman and optical spectroscopy, laser conoscopy, and photoinduced light scattering. An influence of boron dopant on optical uniformity, photoelectrical fields values, and band gap have been also studied by these methods in LiNbO3 crystals. Despite a high concentration of boron in the charge (up to 2 mol%), content in the crystal does not exceed 10−4 wt%. We have calculated that boron incorporates only into tetrahedral voids of crystal structure as a part of groups [BO3]3−, which changes O–O bonds lengths in O6 octahedra. At this oxygen–metal clusters MeO6 (Me: Li, Nb) change their polarizability. The clusters determine optically nonlinear and ferroelectric properties of a crystal. Chemical interactions in the system Li2O–Nb2O5–B2O3 have been considered. Boron, being an active element, structures lithium niobate melt, which significantly influences defect structure and physical properties of a crystal grown from such a melt. At the same time, amount of defects NbLi and concentration of OH groups in LiNbO3:B is close to that in stoichiometric crystals; photorefractive effect, optical, and compositional uniformity on the contrary is higher.

Dispersion stability and thermophysical properties of microencapsulated phase change material slurry for liquid desiccant dehumidification

The dispersion stability and the thermophysical properties of the microencapsulated phase change material slurry (MPCMS) for liquid desiccant dehumidification were investigated experimentally. The results show that, the dispersion stability of the MPCMS can be improved greatly by adding surfactant. The maximum absorbency of MPCMS with polyoxyethylene sorbitan monooleate (Tween80) is 4.1 times that of MPCMS with cetyltrimethyl ammonium bromide (CTAB). The monolayer adsorption model is suitable for predicting the optimal mass content of surfactant with the maximum relative error of 13.3%. The thermal conductivity of MPCMS is lower than that of the base fluid and decreases with the increasing MicroPCMs concentration, when the mass fraction of MicroPCMs increases from 0% to 2.0% at the temperature of 20 °C and 40 °C, the thermal conductivity decreases by 25% and 14.8%, respectively. When the mass concentration of MicroPCMs is lower than 1.0%, the thermal conductivity of MPCMS keeps increase with the temperature rise. While the mass concentration of MicroPCMs ranges from 1.0% to 2.0%, the thermal conductivity of MPCMS increases firstly and then declines gradually. Moreover, an improved interfacial layer based thermal conductivity calculation correlation was proposed, in which the influence of temperature and concentration of MPCMS were considered, the maximum deviation and mean deviation between the calculated value and the experimental one are 5.62% and 1.85%, respectively. In the range of phase transformation temperature, the specific heat capacity of the slurry can be significantly improved by the MicroPCMs, the maximum specific heat capacity of the MPCMS reaches 2.3 times that of the pure lithium chloride aqueous solution. In addition, the effect of the mass concentration of MicroPCMs on the specific heat capacity is much greater than that of the temperature and the mass concentration of LiCl. The findings provide experimental foundation and guidance for the practical application of MPCMS in liquid desiccant dehumidification.

Physical Background, Computations and Practical Issues of the Magnetohydrodynamic Pressure Drop in a Fusion Liquid Metal Blanket

In blankets of a fusion power reactor, liquid metal (LM) breeders, such as pure lithium or lead-lithium alloy, circulate in complex shape blanket conduits for power conversion and tritium breeding in the presence of a strong plasma-confining magnetic field. The interaction of the magnetic field with induced electric currents in the breeder results in various magnetohydrodynamic (MHD) effects on the flow. Of them, high MHD pressure losses in the LM breeder flows is one of the most important feasibility issues. To design new feasible LM breeding blankets or to improve the existing blanket concepts and designs, one needs to identify and characterize sources of high MHD pressure drop, to understand the underlying physics of MHD flows and to eventually define ways of mitigating high MHD pressure drop in the entire blanket and its sub-components. This article is a comprehensive review of earlier and recent studies of MHD pressure drop in LM blankets with a special focus on: (1) physics of LM MHD flows in typical blanket configurations, (2) development and testing of computational tools for LM MHD flows, (3) practical aspects associated with pumping of a conducting liquid breeder through a strong magnetic field, and (4) approaches to mitigation of the MHD pressure drop in a LM blanket.

Large-deformation plasticity and fracture behavior of pure lithium under various stress states

Although lithium-metal anodes are being extensively examined in research projects aiming at pushing the energy density of lithium batteries to its limit, the knowledge about the mechanical properties of pure lithium is insufficient in two aspects. First, most of the available data focuses either on nano- and micro-scale single-crystalline lithium or on macro-scale bulk material. Second, those tests were commonly performed via uniaxial tests in which the stress states were simple or nanoindentation. This work aims at bridging these gaps by performing a systematic experimental program under various stress states on small-sized specimens and by developing a plasticity model that can capture the important characteristics. Based on these experimental and computational findings, the added value on the understanding of the deformation and failure mechanisms of lithium under various stress states and a first quantitative description on the plasticity anisotropy on lithium is provided. In order to manufacture the required complex-shaped specimens for the five different stress states (uniaxial tension, notched tension with two different radii, central hole tension, and simple shear), a method which allows safe laser cutting of thick lithium foil in argon atmosphere is developed. The tensile tests are conducted in pure argon as well as in air to quantify the effect of oxidation on the strength of lithium. By means of post-mortem microstructural examinations, two active slip systems and cross-slip are observed. Lithium fractures in a perfectly ductile manner when the specimen thickness is reduced to zero due to localized necking. Digital image correlation analysis shows that the lithium foil is highly anisotropic in the through-thickness direction although it is in-plane isotropic. By using a rate-dependent transverse isotropic model, a satisfactory prediction of the five experiments is provided.

Thermoelectric properties in multifaceted Bi/lithium cobaltate composites

Thermoelectricity is one of the most appealing way to convert waste heat into electrical energy. Lithium cobaltate was synthesized without water and surfactants (WOWS) by sol–gel method. Composites of phase pure lithium cobaltate were prepared with different weight percent (5%, 10%, 15%) of bismuth. Structural analysis was done by using X-ray diffraction (XRD) technique. XRD of all samples confirmed the rhombohedral structure. Crystallite size of as-prepared sample was found in the range of 10–27 nm and that of sintered composites was found in the range of 29–47 nm. DC electrical properties as a function of temperature was measured by using four-probe method, in the temperature range of 300–413 K. Thermal transport properties of all samples were done by using advantageous transient plane source method. Thermal conductivity, thermal diffusivity, and volumetric heat capacity were measured as a function of temperature in the temperature range of 300–413 K. As expected, it was observed that thermal conductivity of composites with 15% Bi i.e., 1.0866 W/m K at 413 K was very much less than that of lithium cobaltate. Seebeck coefficient was measured as a function of temperature and these were also in line with the electrical and thermal transport data. Variation in Seebeck coefficient is observed both with respect to temperature and the maximum value is obtained with 5% bismuth i.e., 703.89 μV/K.