bluuebunny/crossref_metadata_2025_split huggingface dataset:
Operando Gassing Studies of All-Solid-State Battery Cells
Authors: Teo Jun Hao , Strauss Florian , Janek Jürgen , Brezesinski Torsten 
Published: December 2020

All-solid-state batteries (SSBs) are considered as next-generation energy storage technology with the possibility of higher energy and power densities as well as safety compared to conventional lithium-ion batteries [1]. SSBs with sulfidic solid electrolytes (SEs) as a component are thought to be the closest towards practical implementation [2] despite widely reported side reactions at the cathode active material (CAM)/SE interface. Advances in coating technology have helped suppress these detrimental reactions to a certain extent [3]. We demonstrate the use of differential electrochemical mass spectrometry (DEMS) on evaluating the stability of a protective surface coating [4]. Analysis of the gas evolved provides insights into possible reaction mechanisms at the CAM/SE interface. DEMS was also used to investigate the practical safety performance of sulfide-based SSBs with respect to possible harmful gas evolution such as H2S and SO2 [5].

Key Words: All-solid-state battery, differential electrochemical mass spectrometry, electrochemical energy storage
References

Janek, W. Zeier, Nat. Energy, 1 (2016) 16141.

J. Nam, D. Y. Oh, S. H. Jung, Y. S. Jung, J. Power Sources, 375 (2018) 93–101.

-Y. Kim, F. Strauss, T. Bartsch, J. H. Teo, T. Hatsukade, A. Mazilkin, J. Janek, P. Hartmann, T. Brezesinski, Chem. Mater., 31 (2019) 9664 – 9672.

Bartsch, F. Strauss, T. Hatsukade, A. Schiele, A-Y. Kim, P. Hartmann, J. Janek, T. Brezesinski, ACS Energy Lett., 3 (2018) 2539–2543.

Strauss, J. H. Teo, A. Schiele, T. Bartsch, T. Hatsukade, P. Hartmann, J. Janek, T. Brezesinski, ACS Appl. Mater. Interfaces, 12 (2020), 20462–20468.
(Invited) All-Solid-State Batteries Using Li7La3Zr2O12 Garnet Electrolyte Framework
Authors: Doeff Marca M , Yi Eongyu 
Published: December 2020

All-solid-state batteries (ASSB) using LLZO (variants of Li7La3Zr2O12) garnet solid electrolyte with lithium metal anode potentially offer higher energy density and improved safety. Rational design of cell architecture as well as manufacturing scalability are key aspects to consider as the technology readiness level advances. A thick composite cathode layer attached to a thin solid electrolyte layer is desirable to obtain superior energy densities. Furthermore, the architecture within the composite cathode may be engineered to contain directional conduction paths of lithium ions or electrons for enhanced rate capabilities.
Here, we demonstrate a functioning bulk-type LLZO based all-solid-state battery with a practical form factor incorporating the above described design concepts. Freeze-tape-casting (FTC), a scalable and environmentally friendly ceramic processing method, is used to construct 3D porous LLZO scaffolds composed of vertical arrays of LLZO walls. The thin solid-electrolyte layer is fabricated by tape-casting (TC). By sintering the stacks of FTC and TC green tapes, porous/dense bilayers and porous/dense/porous trilayers of LLZO frameworks are obtained. An ASSB was constructed using a porous/dense bilayer by infiltrating LiNi0.6Mn0.2Co0.2O2 cathode powder and carbon black into the porous layer and adhering lithium metal foil to the dense side. We find it crucial to introduce a plastic crystal based soft solid electrolyte to the porous layer to electrochemically connect all cathode components, obviating the need for co-sintering to establish contact. The soft nature of the plastic crystal based solid-electrolyte may be able to accommodate the volume change of the cathode material as it cycles. In this device, which contained no liquid component, the initial discharge capacities were similar to those observed in a lithium ion battery configuration using the same cathode powder at C/10 rates.
Effect of Excess Na Contents in Precursor on the Property of Na2Zn2TeO6 Ceramic Solid Electrolyte
Authors: Inada Ryoji , Itaya Akihiro , Sakurai Yoji 
Published: December 2020

P2-type layered sodium (Na) ion conducting oxide Na2M2TeO6 (M = Mg, Zn, etc.) have attracted much attention for the application to all-solid-state Na-based batteries with high safety and lower cost, because of the high ionic conductivity above 10-4 S/cm at room temperature range and excellent chemical and electrochemical stability [1, 2]. Generally, Na in precursor materials is easy to volatilize in high temperature processing, so that the excess Na in precursors must be added to compensate the Na loss and suppress the composition shift in final products and undesired secondary phase formation. In this work, we investigated the effect of excess Na contents in precursor on the property of Na2Zn2TeO6 (NZTO) solid electrolyte synthesized via a conventional solid state reaction method.
Na2CO3, ZnO and Te2O3 were used as precursor materials and the excess Na contents were adjusted to 3, 7 and 10% over the stoichiometric composition. They were pulverized and mixed for 3 hours by planetary ball milling and then calcined at 850ºC for 6 hours in air using a SiC crucible. Calcined powders were ground again and then pelletized by cold isostatic pressing at 300 MPa. Finally, the pellets with different excess Na contents were sintered at 850ºC for 12 hours in air using a SiC crucible.
From XRD analysis, P2-type layered NZTO phase were mainly confirmed in all sintered samples, but only the sample with 3% excess Na in precursor contained small amount of secondary phases, which is attributed to the Na volatilization during high temperature processing. From SEM observation, it was confirmed that all sintered samples have porous structures. The relative densities were in the range from 80 to 83% and nearly independent of the excess Na contents.
Au film was formed on both the end surfaces of each sintered NZTO sample as an ion-blocking electrode and electrochemical impedance was measured at 27-202ºC to investigate the ionic conducting property. As results, the ionic conductivity of NZTO samples strongly depends on the excess Na contents in precursor. The sample with 3% excess Na showed the lowest total (grain + grain boudary) conductivity of 0.5 x 10-4 S/cm at room temperature, while the conductivity for the samples with 7 and 10% excess Na was well above 10-4 S/cm. In our experiment, 7% excess Na in precursor is the best and the highest total conductivity of 3.8 x 10-4 S/cm at room temperature and low activation energy of 0.27 eV were obtained. Since the relative density of our NZTO samples are not so high and the contribution of grain-boudary resistance is large at present, the total conductivity could be improved further by densification via optimizing sintering processing.
This work was partly supported by Iketani Science and Technology Foundation.
[1] Y. Li, et al., Chem. Eur. J. 24, 1057-1061 (2018).
[2] Y. Li, et al., ACS Appl. Mater. Interfaces 10, 15760−15766 (2018).

Figure 1
Noble Metal “Shell” Formation on the Surface of Acoustically-Levitated Solvent Droplets
Authors: Abbuhl Kyla , McCardle Harley , Davis James H. , Duranty Edward R. 
Published: December 2020

In the past few years, more and more attention has been focused on processes occurring in small volumes such as microdroplets and thin films due to the increases in reaction rates and other phenomena recently reported in the literature. Our group has primarily investigated the thermodynamics of physical and chemical changes taking place in acoustically-levitated droplets ranging in volume from five to 10 microliters in size. Levitating a droplet using a standing acoustic wave allows for convenient study of reactions occurring within the droplet or any process reliant on the droplet’s surface using visualization techniques such as microphotography and infrared imaging. We have used this technique in the past to study the evaporation process of levitated solvent droplets, including those of ionic liquids, as well as the neutralization thermodynamics of strong acids and bases within a levitated droplet.
In this work we present the initial characterization of droplet “shells” formed on the surface of levitated solvent droplets which contain a noble metal salt and a small piece of transition metal wire. In these experiments silver nitrate or a gold (III) salt was dissolved in a levitated solvent droplet (either in deionized water, silver bis(trifluoromethanesulfonyl)imide ionic liquid, or a DMF/water solution) after which a small (~0.5cm) section of zinc or copper wire was dropped into the levitated drop. The resulting reduction of the noble metal salt to the noble metal solid was observed for each solvent/noble/transition metal combination using a DSLR camera equipped with a close-up lens. In many cases a dark precipitate formed on the surface of the wire, indicating the formation of metal solid much in the same fashion as the silver “tree” general chemistry experiment. However, in the case of the silver nitrate/DI water/copper and gold(III)/DI water/zinc combinations, a metallic solid ( shiny, silver-colored for silver nitrate and black for gold(III)) formed a shell at the droplet/air interface. More study of the shell structures is planned including examination using SEM. While specific applications of these structures is not immediately clear, we envision they may be of interest as high surface area catalysts.

Figure 1
Corrosion of Ceramic and Carbon-Based Materials in FLiNaK
Authors: Polovov Ilya B. , Abramov Aleksandr , Alimgulov Ruslan , Zolotarev Daniil A. , Gibadullina Alfiya F. , Trubcheninova Anastasiya I. , Volkovich Vladimir A. , Khotinov Vladislav A. , Zhilyakov Arkadiy Yu. , Belikov Sergey V. 
Published: December 2020

Molten salt nuclear fast nuclear reactor (MSNFR) is one of the prospective design in frame of Generation IV concept. This technology is also required for reprocessing of spent nuclear fuel (SNF) in molten salts to extract valuable components. Recycling SNF consists of extraction uranium and plutonium with the disposal of minor actinides and fission products. These stages need the materials that retain their corrosion and mechanical properties for long time under the influence of high temperatures, radiation fields and contact with molten salts. Various steels and alloys were widely studied to assess their use under such extreme conditions. Alternative materials include ceramics, composite and carbon materials, which have high corrosion resistance in various media and can be used up to 1000 °C.
In the present work the corrosion and mechanical properties of nitride ceramics (Si3N4 and BN) and carbon-based materials (carbon-carbon composite material (C/C) and high-density carbon) were studied in a molten mixture of lithium, sodium, and potassium fluorides (FLiNaK) in the temperature range of 550–750 °C under inert atmosphere. Corrosion tests were performed under static conditions, and the duration of each test was 100 h to enable the comparison of the experimental data.
It was found that carbon-containing materials (C/C and high-density carbon) showed high corrosion resistance in the melt. C/C samples had lower corrosion rates (less than 0,1 mm/year in the entire temperature range), while the high-density carbon showed better mechanical properties. The main disadvantage of these materials is their impregnation by molten salt due to relative high porosity. However, C/C composite and high-density carbon are promising structural materials for salt media based on FLiNaK in the selected temperature range.
Tested nitride ceramics (BN, Si4N3) demonstrated relatively low corrosion resistance in fluoride systems compare to carbon-containing and metallic materials. The corrosion rates of these materials in FLiNaK exceeded the value of 1 mm/year. The plastic properties of nitride ceramics were also poor. Possible application of such materials for MSNFR and SNF reprocessing is under further investigation.
A Method of Producing Al–REE Master Alloys Using Exchange Reduction Reaction
Authors: Maksimtsev Konstantin V. , Mukhamadeev Andrey S. , Fofanov Grigoriy L. , Rebrin Oleg I. , Polovov Ilya B. 
Published: December 2020

Modern aerospace engineering relies on Al-based alloys with enhanced high-temperature strength properties and oxidation resistance. These requirements can be fulfilled by modifying alloys’ structure employing rare earths metal doping. Direct addition of metallic rare earths to aluminium is complicated due to high chemical activity of molten rare-earth metals and significant vapor pressure of aluminium at elevated temperatures. To overcome these drawbacks, lanthanide-containing master alloys with relatively low REE content can be employed instead of pure scandium.
Currently there are three methods for preparing aluminium-based alloys containing rare earths, i.e. direct fusing, molten salt electrolysis and exchange or metallothermic reduction reactions. In the last case, Al–Gd and Al–Sc master alloy can be prepared by aluminothermic reduction of GdF3 or ScF3 in a molten binary NaF–KCl salt mixture at 800–1050 °С.
In the present work we suggest the modification of the above mentioned method for aluminium–cerium and aluminium–neodymium master alloy production with a lanthanide concentration of 1 to 7 wt. %. Based on thermodynamic calculations we proposed that the high-temperature exchange reaction between metallic aluminum and corresponding fluoride containing salt electrolyte should be carried out at temperatures from 740 to 780 ° C to provide the higher recovery of REE. The influence of the time of the exchange reaction and «aluminium–salt» ratio on the process to obtain ligatures of various compositions is analyzed. The yield higher than 85 % is achieved.
The microstructure of the alloys represents a metal matrix of aluminum in which intermetallic compounds of Ln3Al11 compositions are distributed In the case of an exchange reaction between aluminum and cerium fluoride, the formation of a new phase, presumably related to the Al4Ce intermetallic compound, is found.
Kinetic and Thermodynamic Properties of Samarium Chlorides Dissolved in Alkali Chloride Melts Obtained by Electrochemical Transient Techniques
Authors: Kuznetsov Sergey , Stulov Yuri , Gaune-Escard Marcelle 
Published: December 2020

Lanthanide elements, which are present in spent fuel from fast nuclear reactors can be converted into molten salts by anodic dissolution. The lanthanide elements are the most difficult fission products to separate from actinides due to their similar chemical properties. Thus a knowledge of the electrochemistry and thermodynamics of lanthanide compounds in molten salt systems is very useful for the understanding the recycling of spent nuclear fuel.
The electroreduction of SmCl3 in alkali chloride melts (NaCl-KCl, KCl, CsCl) was studied in the temperature range 973-1173 K by different electrochemical methods. The diffusion coefficients (D) for Sm(III) and Sm(II) were determined by linear sweep voltammetry, chronopotentiometry and chronoamperometry methods showing that D decreases with increase of samarium oxidation state, while the activation energy for diffusion increases. Decreasing values of D were also obtained when the cation in the second coordination sphere changed from Na to Cs. It was shown that such changes are due to the decreasing of counter polarizing effect of cations with increasing cationic radius.
The standard rate constants of charge transfer (k
s) for the Sm(III)/Sm(II) redox couple were calculated on the basis of cyclic voltammetry data using Nicholson’s equation. The following row of the standard rate constants of charge transfer has been experimentally determined: k
s (KCl) < k
s (CsCl) < k
s (NaCl-KCl). The nature of working electrode on the rate of charge transfer for the Sm(III)/Sm(II) redox couple was studied. It was found that the values of k
s determined at a molybdenum electrode were higher than those at a glassy carbon electrode.
The formal redox potentials E*

Sm(III)/Sm(II) were obtained in alkali chlorides melts from the linear sweep voltammetry data. From the values of the formal redox potentials were calculated the Gibbs energies and equilibrium constants for the reaction:
SmCl2(sol.) +1/2 Cl2(g.)
« SmCl3(sol.) (1)
It was determined the increasing of the formal entropy for the reaction (1) in transition from NaCl-KCl to CsCl melt that associated with a greater degree of ordering of the reaction products due to the complex formation.
Application of Phosphate Precipitation for Removing Strontium and Barium from Alkali Chloride Based Melts
Authors: Ivanov Alexander B. , Byzova Elizaveta D. , Volkovich Vladimir A. , Chukin Andrey V. , Griffiths Trevor R. 
Published: December 2020

Alkali chloride based melts can be used as working electrolytes in prospective technologies of pyrochemical reprocessing of spent nuclear fuels. After extracting fissile materials the melts contain ions fission product elements having more negative electrode potentials than uranium and plutonium. These include rare earth, alkaline earth and alkali metals. One of possible methods for removing rare earths from alkali chloride based melts is phosphate precipitation. Alkaline earth metals also form sparingly phosphates and therefore phosphate precipitation can be potentially used for removing strontium and barium from molten electrolytes.
The present work was aimed at studying the reaction of solutions of strontium or barium chloride in alkali chloride based melts with sodium orthophosphate. The experiments were conducted in LiCl–KCl and NaCl–KCl–CsCl eutectic based melts at 550 oC, and in NaCl–KCl equimolar mixture at 750 oC.
To determine the conditions required for complete removal of strontium and barium, the initial phosphate-to-barium molar ratio in the melt was set at 0.5; 1; 2; 4; 6 and 8. Residual alkaline earth content in the melt was determined by chemical analysis. Precipitated strontium and barium phosphates were subjected to X-ray powder diffraction analysis.
Selecting a possible method of separating solid precipitate from molten salt requires information on size of particles forming the solid phase. Particle size was determined by laser diffraction and examples of particle size distribution curves for precipitates formed in LiCl–KCl–BaCl2 melts are shown in Fig. The precipitates consisted of particles ranging from 0.5 to 100 microns. Increasing the initial PO4
3– : Ba2+ molar ratio resulted in increasing particle size but even at the molar ratio of six over 50 % particles were less than 10 μm.
Fig. Particle size distribution curves for barium phosphate precipitated from LiCl–KCl eutectic based melts at 550 oC. Initial PO4
3– : Ba2+ mole ratio was 0.5 (line 1); 1.0 (2); 2.0 (3); 4.0 (4) and 6.0 (5).

Figure 1
Electrochemical Bechaviour of Cobalt and Tungsten Oxides in Molten Carbamide
Authors: Devyatkin Sergei Vladimirovich , Kochetova Svetlana , Pisanenko Alexandr Dmitrievich , Bogdanovich Ludmila Vasilevna , Bykov Valeriy 
Published: December 2020

The electrodepositions of tungsten and its alloys has been of considerable interest because of usual properties of the metal and alloys. The electrodepositions of W and Co from water solutions and Na2WO4-WO3-CoO at 1023 K were investigated in more works. The possibility of electrodeposition of W-Co alloys from carbamide melts at 408 K has been examined. When studying the electrochemical behaviour of cobalt and tungsten oxides and its compounds (WO3, Li2WO4, Na2WO4, K2WO4) in molten carbamide, it can be concluded that maximum limiting currents are typical of the system (NH2)2CO-Li2WO4. Cyclic voltammograms showed the potentials of deposition of tungsten and cobalt. Layered Co-W coatings on nickel cathodes have been obtained by the electrolysis of the molten system (NH2)2CO-CoO- Li2WO4 at current densities of 5-10 mA/cm2. The cathodic products were analyzed by XRD and JEM-2100F SEM.
Fig. SEM of the surface morphology of W-Co coating deposited by electrolysis from (NH2)2CO-CoO- Li2WO4 melt.

Figure 1
Electrochemical Behavior of Titanium Complexes in the KCl-KF Melt with Additions of Alkaline Earth Metal Cations
Authors: Vetrova Daria A. , Kuznetsov Sergey 
Published: December 2020

The goal of the present investigation was to study of Mg2+, Ca2+, Sr2+ and Ва2+ strongly polarizing cations influence on the standard rate constants of charge transfer (ks
) for the redox couple Ti(IV)/Ti(III) in the KCl-KF(10 wt.%)-K2TiF6 melt.
Electrochemical studies were carried out in the temperature range of 1073-1173 K by cyclic voltammetry. Voltammetric curves were recorded at a glassy carbon electrode vs. a glassy carbon quasi-reference electrode. The sweep rate (v) varied from 0.1 up to 2.0 V s-1. The electrochemical redox process Ti(IV)+e-↔Ti(III) was classified as quasi-reversible at a sweep rate 1.0 V s-1≤ν≤2.0 V s-1.
The values of k
s were calculated by using the Nicholson’s method [1]. It was shown that k
s increase with increasing the temperature. It is due to the number of particles capable of overcoming the potential barrier increases [2].
Addition of alkaline earth metal cations resulted in increasing of ks
up to the certain ratio of Me2+/Ti(IV) for all alkaline earth metal cations. It was determined the linear dependence of ks
on ionic potential of alkaline earth metal cations.
The activation energies of the charge transfer in the case of strongly polarizing cations addition were calculated. It was shown that values of the activation energy for molten systems with strongly polarizing cations are considerably less than activation energy of the initial melt and decrease with increasing of ionic potential.
It was determined that the k
s for the redox couple Ti(IV)/Ti(III) in the KCl-KF(10 wt.%)-K2TiF6 melt (for all systems) are less than k
s in the NaCl-KCl based melt [3].
References:
[1] R.S. Nicholson, J. Anal. Chem., 1965. Vol. 37 (1965), 1351.
[2] B.B. Damaskin, O.A. Petriy, Introduction of electrochemical kinetics, Vysshaya Shkola Publ., Moscow, 1975 (in Russian).
[3] D.A.Vetrova, S.A. Kuznetsov, Proceedings of the Kola Science Center RAS, 2015. P. 214.