bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corrosion of Metallic Materials in 3LiCl-2KCl and 3LiCl-2KCl-UCl3
Authors: Alimgulov Ruslan , Trubcheninova Anastasia I. , Abramov Aleksandr , Zhilyakov Arkadiy Yu. , Belikov Sergey V. , Rebrin Oleg I. , Polovov Ilya B. 
Published: December 2020

High-temperature molten salts are widely used in production and refining of non-ferrous and rare metals, in nuclear technology and solar storage systems. However, application of such technologies is limited by the problem of finding suitable corrosion resistant materials capable of withstanding a prolonged contact with molten salts.Current study is focused on the corrosion of metallic materials in 3LiCl-2KCl-based melts.
Metallic tantalum and molybdenum, nickel-chromium-molybdenum alloys (VDM Alloy C-4, Hastelloy G-35 and specially designed KhN62M alloy) were chosen as the objects of the investigation. Corrosion tests were performed in 3LiCl-2KCl and 3LiCl-2KCl-UCl3 (5 wt. % U) melts. The corrosion tests run for 100 h, and the temperature was varied from 450 to 750 °C. The corrosion rates were determined by both gravimetric technique and chemical analysis of quenched melts. The last technique is very useful in case of alloys formation on the surface of tested samples.
It was found that all the above metallic materials can be used in 3LiCl-2KCl melts at 450 and 550 °C. Increasing working temperature led to intensification of corrosion processes. This effect was more pronounced for nickel-based alloys where increasing temperature to 650 °C also resulted in changing character of the corrosion. The undesirable intergranuluar corrosion was noticed for the nickel-based alloys at 750 °C and this was induced by the formation of secondary phases at the grain boundaries.
Metallic tantalum and molybdenum were subjected to only gradual etching even at 750 °C. Their corrosion rates did not exceed 0.01 mm/year and these materials can be recommended for the application in contact with molten chlorides at 750 °C.
Addition of uranium(III) chloride to the melt led to increasing corrosion rate for all the materials studied. The corrosion mechanism, however, did not change much with temperature. The presence of oxidant (U3+) resulted in acceleration of corrosion etching. The rate of the exchange reaction between uranium chlorides and components of the materials can be accelerated by the formation of U-Ni alloys. Formation of metallic uranium-containing layers on the surface of nickel-based samples deserves a separate attention as an element of possible currentless protection coatings.
The corrosion resistance of tantalum and molybdenum is also sufficient at 750 °C in 3LiCl-2KCl-UCl3 (5 wt. % U). However, it should be remembered that their mechanical properties, weldability, and high-temperature resistance in air are noticeably worse compare to the nickel-based alloys.
Kinetics of Reaction of Oxygen with Uranium(IV) Chloride in Alkali Chloride Melts
Authors: Volkovich Vladimir A. , Ivanov Alexander B. , Ryzhov Alexander A. , Maltsev Dmitry , Griffiths Trevor R. 
Published: December 2020

Alkali chloride melts have numerous potential applications in nuclear fuel cycle including pyrochemical reprocessing of spent nuclear fuels, uranium electrowinning and electrorefining. Oxygen is a common technological impurity that can affect uranium speciation and behavior in fused salts. The present work was devoted to studying the reactions of oxygen with solutions of uranium tetrachloride in molten alkali chlorides. The experiments were performed in LiCl–KCl, NaCl–KCl–CsCl and NaCl–CsCl eutectic based melts at 450–750 oC. Pure oxygen and argon–oxygen mixtures (containing ca. 1 and 10 % O2) were used. Amount of oxygen passed through the melt varied from less than one to over 100 moles per mole of uranium present. Effect of moisture (0.4–2.5 % H2O) presence in oxygen or Ar–O2 mixtures was also investigated. The course of the reaction was followed by in situ electronic absorption spectroscopy measurements with the spectra recorded at the certain time intervals.
Depending on temperature, cationic melt composition and oxygen-to-uranium molar ration the reaction resulted in oxidation of uranium(IV) to soluble uranyl chloride and/or precipitation of uranium dioxide. Analysis of the spectra provided the information on kinetics of U(IV) concentration change. Increasing temperature, O2 : U(IV) molar ratio or decreasing mean radius of alkali cations of the solvent melt resulted in faster decrease of U(IV) concentration in the melt.
Under certain conditions U(IV) can be oxidized to UO2Cl4
2– without precipitation of UO2. Therefore sparging the melt with oxygen can be used as a way of separating uranium from certain fission products, for example rare earth elements. Rare earth chlorides react with oxygen yielding oxychlorides or oxides insoluble in alkali chloride melts. Interaction of oxygen with melts containing a mixture of uranium and rare earth chlorides was therefore also investigated and an example of the spectra recorded in LiCl–KCl–UCl4–NdCl3 melt is shown in Fig.
Fig. Spectra recorded in the course of reaction of O2 with LiCl–KCl–UCl4–NdCl3 melt at 550 oC. Arrows show the direction spectra changed.

Figure 1
Utilizing X-Ray Absorption Spectroscopy to Investigate Solute-Solvent Interactions in Molten Salt Environments
Authors: Dias Elaine , Gill Simerjeet , Huang Jiahao , Mausz Julia , Gakhar Ruchi , Roy Santanu , Topsakal Mehmet , Phillips William C. , Layne Bobby H. , Mahurin Shannon , Halstenberg Philip , Dai Sheng , Wishart James F. , Bryantsev Vyacheslav , Frenkel Anatoly 
Published: December 2020

Molten Salt Reactors (MSRs) are the leading candidates out of the six-generation IV advanced nuclear power reactor designs chosen for deployment for nuclear energy in US. MSR technology is particularly attractive due to better passive safety, operation at atmospheric pressure, high thermal efficiency, lower spent fuel per unit energy and increased solubility of fission products in molten salts.
To facilitate robust and economical design of such systems, accurate knowledge and fundamental understanding of the structure and speciation of salts and metals in and near molten salt environments is necessary. Speciation of solutes is important because it determines how chemical behavior in solution and complex speciation from fission and corrosion products impact kinetic, thermodynamic, and transport properties of the molten salt systems. Investigating effects of radiation on metallic species and radiation-induced nucleation and growth of metallic nanoparticles under ionizing radiation is crucial for predicting the stability and reactivity of molten salts.
Molten Salts in Extreme Environments (MSEE) EFRC aims to investigate speciation of metals and radiation-induced reactions in molten salt systems by utilizing synchrotron based XAS methods. In our work, Extended X-ray Absorption Fine Structure (EXAFS) and X-Ray Absorption Near Edge structure (XANES) are used to investigate local coordination environment and chemical structure of metal species such as Nickel in Zinc Chloride based molten salt systems. In addition, the effect of metal concentration and temperature on changes in local and chemical structure of metal is studied. XAS studies are complemented by optical ultra-violet spectroscopy studies of molten salts, enabling a direct correspondence between UV-Vis peak shape and coordination geometry and number, determined by EXAFS. Such knowledge of speciation of metals and radiation-induced nanoparticles in molten salt environments will provide critical understanding needed to predict and control the physical and chemical properties of molten salts and corrosion mechanisms in molten salt systems. This work was supported as part of the Molten Salts in Extreme Environments, Energy Frontier Research Center, funded by the U.S. Department of Energy Office of Science.
Corrosion of Metallic Materials in the Molten FLiNaK
Authors: Polovov Ilya B. , Abramov Aleksandr , Alimgulov Ruslan , Zolotarev Daniil A. , Trubcheninova Anastasiya I. , Gibadullina Alfiya F. , Volkovich Vladimir A. , Zhilyakov Arkadiy Yu. , Khotinov Vladislav A. , Belikov Sergey V. 
Published: December 2020

Molten ﬂuoride salts can be used as the fuel and coolant for molten salt reactors (MSR) and electrolytes for spent nuclear fuel (SNF) reprocessing. 46.5%LiF-11.5%NaF-42%KF (FLiNaK) melt is the prospective media for these purposes due to their desirable thermophysical and nuclear properties. Finding construction materials with sufficient corrosion and mechanical resistance is the most challenging task for practical implementation of MSR concept.
In the present study the corrosion and mechanical properties of different types of construction materials were investigated. The materials included various low carbon Ni-Cr-Fe-Mo, Ni-Cr-Mo, and Ni-Mo alloys, and metals with relatively positive electrode potentials.
The corrosion experiments were performed in FLiNaK melt at different temperatures (from 550 to 750 °C) in the specially designed stainless steel cells under high-purity argon atmosphere. Corrosion properties of studied materials were investigated under static conditions, and the duration of each test was 100 h to enable the comparison of the experimental data. In a special series of experiments fluorides of typical fissile nuclides and fission products were added to the salt electrolyte to estimate the influence of the red-ox potential on the corrosion resistance of the materials.
Corrosion rates were determined from the weight loss measurements and chemical analysis of quenched melts. Surface and microstructure of corroded samples was examined by various microscopic techniques. Mechanical properties of investigated materials were also studied at the ambient temperature and at 600 °C.
Advantages and limitations of different types of construction materials were evaluated on the basis of data obtained. The effect of temperature on corrosion and mechanical properties of the studied materials were determined. Possible mechanisms of corrosion of various materials in fluoride melts were proposed.
The alloys based on Ni-Cr-Mo and Ni-Mo systems, and molybdenum and its alloys were selected for further long-time tests under dynamic conditions to determine the resource of materials in contact with molten fluorides for MSR and SNF recycling technologies.
(Invited) Evolution of Structural, Transport and Electrical Properties of Binary Ionic Liquids in the Presence of Graphite
Authors: Shah Jindal 
Published: December 2020

The flexibility to manipulate various interactions in ionic liquids by changing the cation, anion, or the various functional groups on the ions has drawn researchers to design tailor-made ionic liquids for a given application. Another approach that is gaining importance in tuning the properties of ionic liquids is to form binary, ternary, and reciprocal ionic liquid mixtures. Results from molecular simulations conducted in our research group have demonstrated that the binary ionic liquid mixtures in which two anions are combined in different molar ratios for a given cation can lead to either native or non-native structures in the bulk depending on the difference between the hydrogen bonding ability of the participating anions. The non-native structures differ markedly from those for the pure ionic liquid analogues and impact the physical dissolution mechanism for gases such as CO2.
Given the importance of ionic liquids as electrolytes in the next-generation of batteries, it is likely that such ionic liquid mixtures will increasingly be investigated for their ability to transport ions to and from charged surfaces. However, very little is currently known regarding how the presence of a surface or an interface affects the local and long-range structures of binary ionic liquids. In this talk, we will present our findings from molecular simulation studies by examining the structural response of binary ionic liquid mixtures comprised of a single cation in combination with two anions when presented with a graphite surface. We will compare and contrast these structures to those obtained when binary ionic liquid mixtures are formed with a single anion and two cations and a graphite surface is introduced. Additionally, we will elucidate the influence of graphite on the transport and electrical properties of binary ionic liquids.
Advancing Low Temperature Molten Sodium Batteries By Interfacial Engineering of Ceramic Electrolytes
Authors: Gross Martha , Peretti Amanda , Small Leo J. , Percival Stephen , Rodriguez Mark , Spoerke Erik D. 
Published: December 2020

Molten sodium batteries show remarkable promise as large-scale energy storage systems, but their widespread deployment has been limited by high operating temperatures (~300°C), which impacts their lifetime, cost, and reliability. Lowering the battery operating temperature promises substantial improvements in these areas, but the lower temperature introduces new challenges to the battery chemistry, especially related to the solid state ion-conducting separators used in these batteries. Traditionally, the high temperature operation has been required to not only maintain high Na+-ion conductivity of solid electrolytes, such as β”-Al2O3 or NaSICON, but also to improve the liquid-solid interfacial wetting of molten sodium on the solid electrolyte. We are focused on drastically reducing the operating temperature to near the melting temperature of sodium (97.8oC), which leads to poor interfacial wetting of the molten sodium. Poor wetting and ineffective charge transfer can dominate battery resistances resulting in a cell-limiting interface. Here, we will describe the rational design of engineered coatings to improve wetting of the molten sodium on NaSICON at low temperatures near 100°C, and therefore improve charge transfer across this critical interface. Enhanced mating of the separator-sodium interface by means of engineered coatings is demonstrated to result in lower interfacial resistance and higher battery performance at increased current densities. This strategy promises substantial advances in the operation of molten sodium batteries at low temperatures and opportunities to expand the utility of these batteries to meet emerging grid-scale needs.
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
(Invited) Interface Stability in All-Solid-State Batteries
Authors: Battaglia Corsin 
Published: December 2020

All-solid-state batteries combining an alkali metal anode and a high-voltage cathode have the potential to achieve high energy density. However, interface stability remains a major challenge. On the anode side, dendrite formation limits the maximum plating current density and prevents fast charging, while on the cathode side the limited oxidative stability of most solid electrolytes is a major challenge, especially when the battery is charged beyond 4 V.
Here we demonstrate that the critical current density for dendrite formation in the archetypical ceramic solid electrolyte Na-β”-alumina is ten times higher than that measured on a garnet-type Li7La3Zr2O12 electrolyte under equivalent conditions and reaches up to 12 mA/cm2 at room temperature [1]. Further, we show that above the melting temperature of sodium, a cumulative capacity of >10 Ah of sodium can be plated and stripped at an enormous current density of 1000 mA/cm2 without dendrite formation [2].
On the cathode side, we have been developing hydroborate solid electrolytes reaching ionic conductivities >1 mS/cm at room temperature [3]. We already demonstrated the integration of these electrolytes with a 3 V class cathode [4, 5], but recently managed to obtain stable cycling with a 4 V class cathode through the formation of a passivating interface [6]. Combined with their low gravimetric density <1.2 g/cm3, low toxicity, high thermal and chemical stability, stability vs lithium and sodium metal anodes, soft mechanical properties enabling cold pressing [4], compatibility with solution infiltration [7], and potential for low cost [8, 9], hydroborate electrolytes represent a promising option for a competitive future all-solid-state battery.
[1] M.-C. Bay, M. Wang, R. Grissa, M. V. F. Heinz, J. Sakamoto, C. Battaglia, Adv. Energy Mater. 2019, 201902889
[2] D. Landmann, G. Graeber, M. V. F. Heinz, S. Haussener, C. Battaglia, submitted
[3] L. Duchêne, A. Remhof, H. Hagemann, C. Battaglia, Energy Storage Mater. 2020, 25, 782
[4] L. Duchêne, R.-S. Kühnel, E. Stilp, E. Cuervo Reyes, A. Remhof, H. Hagemann, C. Battaglia, Energy Environ. Science 2017, 10, 2609
[5] R. Asakura, L. Duchêne, R.-S. Kühnel, A. Remhof, C. Battaglia, ACS Appl. Energy Mater. 2019, 2, 6924
[6] R. Asakura, D. Reber, L. Duchêne, A. Remhof, H. Hagemann, C. Battaglia, submitted
[7] L. Duchêne, D. H. Kim, Y. B. Song, S. Jun, R. Moury, A. Remhof, H. Hagemann, Y. S. Jung, C. Battaglia, Energy Storage Mater., 2020, 26, 543
[8] A. Gigante, L. Duchêne, R. Moury, M. Pupier, A. Remhof, H. Hagemann, ChemSusChem 2019, 12, 4832
[9] S. Payandeh, R. Asakura, P. Avramidou, D. Rentsch, Z. Lodziana, R. Cerny, A. Remhof, C. Battaglia, Chem. Mater. 2020, 32, 1101
Integrated Modeling Framework for Investigating Multiscale Microstructural Impacts on the Ionic Conductivity of Garnet Solid Electrolytes
Authors: Heo Tae Wook , Grieder Andrew , Akhade Sneha A , Wan Liwen , Adelstein Nicole , Wood Brandon C. 
Published: December 2020

Although recent years have seen the emergence of several solid electrolyte candidates with intrinsically high ionic conductivities for all-solid-state batteries, practical processing and synthesis routes often generate grain boundaries and other interfaces that can perturb primary conduction channels. In this talk, we will present our development of a multiscale modeling framework for predicting the effective ionic conductivity through a solid electrolyte with a complex polycrystalline microstructure, which allows us to address challenges associated with directly probing these effects. We first demonstrate an efficient mesoscopic computational method for predicting the effective ionic conductivity through a solid electrolyte with a complex polycrystalline microstructure. By considering the interplay between concurrent grain boundary and bulk conduction modes, this method surpasses simplified circuit descriptions to account for realistic, nontrivial networks of conduction channels. Using the Li7-x
La3Zr2O12 (LLZO) garnet solid electrolyte as a technologically relevant model system, we then parameterize our simulation framework using a multiscale approach that connects synthetic microstructures from phase-field simulations with diffusivity tensors from molecular dynamics simulations of ordered and disordered systems. Systematically designed simulations of the effective ionic conductivity of polycrystalline LLZO are applied to elucidate the relationship between relevant microstructural features and overall ionic transport properties, with a focus on topological features of grains and grain boundary networks. In particular, we will discuss atomistic and mesoscopic tunability of grain boundary and microstructure, respectively, controlling mass transport in LLZO. We identify specific instances in which competition between conduction modes results in a high sensitivity to microstructural features, highlighting the need to account for the detailed microstructural information when assessing mass transport in LLZO and related solid electrolyte materials, while simultaneously offering design guidance for achieving desired ionic transport properties in processed polycrystalline LLZO.
This work of was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
(Keynote) Transport and Mechanical Property Targets for Enabling Solid State Batteries
Authors: Barai Pallab , Kim Hong-Keun , Srinivasan Venkat 
Published: December 2020

Solid state batteries have become a popular topic of research in the past few years, driven by recent discoveries of solid ion conductors with high ionic conductivity. With these developments, the old problems of dendrite growth and the new problems related to interface delamination between the cathode and the solid electrolyte have become a focus of the research. While new materials are being researched that show promise, they suffer from a combination of low ionic transport properties to provide the necessary rate capability and/or from insufficient mechanical strength to prevent dendrites.
Over the past several years, we have been developing mathematical methods that combine electrochemical effects (kinetics, mass transfer and ohmic) with mechanical interactions (elastic deformation, plastic deformation, and fracture) to understanding the role of material properties and operating conditions on the chemo-mechanics at the interface of both Li-metal anode and of the oxide cathode. These models have provided deep insights into the present status of polymers when used in electric vehicle applications and the targets to achieve the necessary energy and power requirements. In addition, these models have helped understand the reason for the formation of dendrites and interface delamination on the cathode/solid electrolyte interface and the targets to prevent these detrimental phenomena. Studies provide insights into the role of soft and hard materials, impact of cell pressure, and the importance of transference number on cell behavior.
In this talk, we will summarize the research efforts around solid state batteries and call attention to the controlling factors that need to be the focus of future material innovations.
Quantifying the Influence of the Electrode Porous Structure on Lithium-Ion Battery Performance
Authors: Gulsoy Begum , Atalay Selcuk 
Published: December 2020

The growing demand of lithium-ion batteries (LIBs) on portable electronics, electric vehicles urgently requires higher energy density, longer cycling life, and better safety to satisfy the needs of environmental factors and economics. In order to have higher energy density, simply increasing the volume of the single electrodes of LIB results in poor capacity due to inefficient mass transport of Li ions through the irregular microstructure of the electrode. Since understanding the influence of geometrical properties electrodes is of considerable significance to battery performance, we investigate two basic cells: (i) an irregular microstructure intercalation host and (ii) a periodically aligned microchannel intercalation hosts. Our in-house developed simulation tool solves Nernst-Planck and electron conduction equations with proper interfacial reactions by considering experimentally verified ageing mechanism (2-layered SEI and lithium-plating) into account and compute the associated characteristic voltage vs. state of charge curves under various geometric and design parameters. The proposed model is parameterized and optimised for mass transport based on fresh cell and validated against experimental results available on the literature. We show that the nanostructured electrode design yields better battery performance because the uniformity of electrodes yields elimating the nonuniform intercalation and side reactions on active material electrode surface. This work presents a design concept for higher energy and power densities that are not limited to LIBs.
*This work has been supported by The Warwick Research Development Fund, UK, through the Grant No. RDF19035.

Figure 1