Rapid Crystallization and Kinetic Freezing of Site-Disorder in the Lithium Superionic Argyrodite Li6PS5Br

Lithium argyrodite superionic conductors are currently being investigated as solid electrolytes for all-solid-state batteries. Recently, in the lithium argyrodite Li6PS5X (X = Cl, Br, I), a site-disorder between the anionsS2–and X–has been observed, which strongly affects the ionic transport and appears to be a function of the halide present. In this work, we show how such disorder in Li6PS5Br can be engineered viathe synthesis method. By comparing fast cooling (i.e. quenching) to more slowly cooled samples, we find that anion site-disorder is higher at elevated temperatures, and that fast cooling can be used to kinetically trap the desired disorder, leading to higher ionic conductivities as shown by impedance spectroscopy in combination with ab-initiomolecular dynamics. Furthermore, we observe that after milling, a crystalline lithium argyrodite can be obtained within one minute of heat treatment. This rapid crystallization highlights the reactive nature of mechanical milling and shows that long reaction times with high energy consumption are not needed in this class of materials. The fact that site-disorder induced viaquenching is beneficial for ionic transport provides an additional approach for the optimization and design of lithium superionic conductors.

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A Lattice Dynamical Approach for Finding the Lithium Superionic Conductor Li3ErI6

10.26434/chemrxiv.11627451 ◽

2020 ◽

Author(s):

Roman Schlem ◽

Tim Bernges ◽

Cheng Li ◽

Marvin Kraft ◽

Nicolo Minafra ◽

...

Keyword(s):

Lattice Dynamics ◽

Ionic Conductivities ◽

Ionic Transport ◽

Superionic Conductors ◽

Material System ◽

Ionic Conductors ◽

Anion Sublattice ◽

Temperature Dependent ◽

Solid State Batteries ◽

Debye Frequency

Driven by the increasing attention that the superionic conductors Li3MX6 (M = Y, Er, In, La; X = Cl, Br, I) have gained recently for the use of solid-state batteries, and the idea that a softer, more polarizable anion sublattice is beneficial for ionic transport, here we report Li3ErI6, the first experimentally-obtained iodine-based compound within this material system of ionic conductors. Using a combination of synchrotron and neutron diffraction, we elucidate the structure, the lithium positions and possible diffusion pathways of Li3ErI6. Temperature-dependent impedance spectroscopy shows low activation energies of 0.37 and 0.38 eV alongside promising ionic conductivities of 0.65 mS·cm-1 and 0.39 mS·cm-1directly after ball milling and the subsequently annealed Li3ErI6, respectively. Speed of sound measurements are used to determine the Debye frequency of the lattice as a descriptor of the lattice dynamics and overall lattice softness, and Li3ErI6 is compared to the known material Li3ErCl6. The softer, more polarizable framework from the iodide anion leads to improved ionic transport, showing that the idea of softer lattices holds up in this class of materials. This work provides Li3ErI6 as an interesting novel framework for optimization in the class of halide-based ionic conductors.

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Mechanochemical Synthesis: A Tool to Tune Cation Site Disorder and Ionic Transport Properties of Li 3 MCl 6 (M = Y, Er) Superionic Conductors

Advanced Energy Materials ◽

10.1002/aenm.201903719 ◽

2019 ◽

Vol 10 (6) ◽

pp. 1903719 ◽

Cited By ~ 23

Author(s):

Roman Schlem ◽

Sokseiha Muy ◽

Nils Prinz ◽

Ananya Banik ◽

Yang Shao‐Horn ◽

...

Keyword(s):

Transport Properties ◽

Mechanochemical Synthesis ◽

Ionic Transport ◽

Superionic Conductors ◽

Cation Site ◽

Site Disorder

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Diffuson-mediated thermal and ionic transport in superionic conductors

10.33774/chemrxiv-2021-3zxh4 ◽

2021 ◽

Author(s):

Tim Bernges ◽

Riley Hanus ◽

Bjoern Wankmiller ◽

Kazuki Imasato ◽

Siqi Lin ◽

...

Keyword(s):

Thermal Conductivity ◽

Solid State ◽

Thermal Transport ◽

Ionic Conductivities ◽

Ionic Transport ◽

Superionic Conductors ◽

Design Strategies ◽

Dynamics Modeling ◽

Physical Relationship ◽

Low Thermal Conductivity

Ultra-low lattice thermal conductivity as often found in superionic compounds is greatly beneficial for thermoelectric performance, however, a high ionic conductivity can lead to device degradation. Conversely, high ionic conductivities are searched for materials in solid-state battery applications. It is commonly thought that ionic transport induces low thermal conductivity and that ion and thermal transport are not completely independent properties of a material. However, no direct comparison or underlying physical relationship has been shown between the two. Here we establish that ionic transport can be varied independent of thermal transport in Ag+ superionic conductors, even though both phenomena arise from atomic vibrations. Thermal conductivity measurements, in conjunction with two-channel lattice dynamics modeling, reveals that the vast majority of Ag+ vibrations have non-propagating diffuson-like character, which provides a rational for how these two transport properties can be independent. Our results provide conceptually novel lattice dynamical insights to ionic transport and confirm that ion transport is not a requirement for ultra-low thermal conductivity. Consequently, this work bridges the fields of solid state ionics and thermal transport, thus providing design strategies for functional ionic conducting materials from a vibrational perspective.

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A Lattice Dynamical Approach for Finding the Lithium Superionic Conductor Li3ErI6

10.26434/chemrxiv.11627451.v1 ◽

2020 ◽

Author(s):

Roman Schlem ◽

Tim Bernges ◽

Cheng Li ◽

Marvin Kraft ◽

Nicolo Minafra ◽

...

Keyword(s):

Lattice Dynamics ◽

Ionic Conductivities ◽

Ionic Transport ◽

Superionic Conductors ◽

Material System ◽

Ionic Conductors ◽

Anion Sublattice ◽

Temperature Dependent ◽

Solid State Batteries ◽

Debye Frequency

Driven by the increasing attention that the superionic conductors Li3MX6 (M = Y, Er, In, La; X = Cl, Br, I) have gained recently for the use of solid-state batteries, and the idea that a softer, more polarizable anion sublattice is beneficial for ionic transport, here we report Li3ErI6, the first experimentally-obtained iodine-based compound within this material system of ionic conductors. Using a combination of synchrotron and neutron diffraction, we elucidate the structure, the lithium positions and possible diffusion pathways of Li3ErI6. Temperature-dependent impedance spectroscopy shows low activation energies of 0.37 and 0.38 eV alongside promising ionic conductivities of 0.65 mS·cm-1 and 0.39 mS·cm-1directly after ball milling and the subsequently annealed Li3ErI6, respectively. Speed of sound measurements are used to determine the Debye frequency of the lattice as a descriptor of the lattice dynamics and overall lattice softness, and Li3ErI6 is compared to the known material Li3ErCl6. The softer, more polarizable framework from the iodide anion leads to improved ionic transport, showing that the idea of softer lattices holds up in this class of materials. This work provides Li3ErI6 as an interesting novel framework for optimization in the class of halide-based ionic conductors.

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Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100155232 ◽

1989 ◽

Vol 47 ◽

pp. 652-653

Author(s):

Charles W. Allen ◽

Robert C. Birtcher

Keyword(s):

Elevated Temperatures ◽

Ion Irradiation ◽

Ion Beam ◽

National Laboratory ◽

Argonne National Laboratory ◽

Heavy Ion ◽

High Energy ◽

Mechanical Twinning ◽

In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

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Mechanochemical Synthesis and Nitrogenation of the Nd1.1Fe10CoTi Alloy for Permanent Magnet

Molecules ◽

10.3390/molecules26133854 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3854

Author(s):

Hugo Martínez Sánchez ◽

George Hadjipanayis ◽

Germán Antonio Pérez Alcázar ◽

Ligia Edith Zamora Alfonso ◽

Juan Sebastián Trujillo Hernández

Keyword(s):

Mechanochemical Synthesis ◽

Applied Field ◽

Volume Fraction ◽

Synthesis Method ◽

High Energy ◽

Direction Parallel ◽

Best Value ◽

Heat Treated ◽

Bcc Phase ◽

First Time

In this work, the mechanochemical synthesis method was used for the first time to produce powders of the nanocrystalline Nd1.1Fe10CoTi compound from Nd2O3, Fe2O3, Co and TiO2. High-energy-milled powders were heat treated at 1000 °C for 10 min to obtain the ThMn12-type structure. Volume fraction of the 1:12 phase was found to be as high as 95.7% with 4.3% of a bcc phase also present. The nitrogenation process of the sample was carried out at 350 °C during 3, 6, 9 and 12 h using a static pressure of 80 kPa of N2. The magnetic properties Mr, µ0Hc, and (BH)max were enhanced after nitrogenation, despite finding some residual nitrogen-free 1:12 phase. The magnetic values of a nitrogenated sample after 3 h were Mr = 75 Am2 kg–1, µ0Hc = 0.500 T and (BH)max = 58 kJ·m–3. Samples were aligned under an applied field of 2 T after washing and were measured in a direction parallel to the applied field. The best value of (BH)max~114 kJ·m–3 was obtained for 3 h and the highest µ0Hc = 0.518 T for 6 h nitrogenation. SEM characterization revealed that the particles have a mean particle size around 360 nm and a rounded shape.

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Bridging the Gap Between Simulated and Experimental Ionic Conductivities in Lithium Superionic Conductors

Materials Today Physics ◽

10.1016/j.mtphys.2021.100463 ◽

2021 ◽

pp. 100463

Author(s):

Ji Qi ◽

Swastika Banerjee ◽

Yunxing Zuo ◽

Chi Chen ◽

Zhuoying Zhu ◽

...

Keyword(s):

Ionic Conductivities ◽

Superionic Conductors

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Monocarborane cluster as a stable fluorine-free calcium battery electrolyte

Scientific Reports ◽

10.1038/s41598-021-86938-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kazuaki Kisu ◽

Sangryun Kim ◽

Takara Shinohara ◽

Kun Zhao ◽

Andreas Züttel ◽

...

Keyword(s):

Room Temperature ◽

Coulombic Efficiency ◽

Low Cost ◽

Ionic Conductivities ◽

High Energy ◽

High Energy Density ◽

Free Calcium ◽

Energy Storage Devices ◽

Storage Devices ◽

Battery Electrolyte

AbstractHigh-energy-density and low-cost calcium (Ca) batteries have been proposed as ‘beyond-Li-ion’ electrochemical energy storage devices. However, they have seen limited progress due to challenges associated with developing electrolytes showing reductive/oxidative stabilities and high ionic conductivities. This paper describes a calcium monocarborane cluster salt in a mixed solvent as a Ca-battery electrolyte with high anodic stability (up to 4 V vs. Ca2+/Ca), high ionic conductivity (4 mS cm−1), and high Coulombic efficiency for Ca plating/stripping at room temperature. The developed electrolyte is a promising candidate for use in room-temperature rechargeable Ca batteries.

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Residual Stress Evolution during Decomposition of Ti(1-x)Al(x)N Coatings Using High-Energy X-Rays

Materials Science Forum ◽

10.4028/www.scientific.net/msf.524-525.619 ◽

2006 ◽

Vol 524-525 ◽

pp. 619-624 ◽

Cited By ~ 2

Author(s):

Mark R. Terner ◽

Peter Hedström ◽

Jonathan Almer ◽

J. Ilavsky ◽

Magnus Odén

Keyword(s):

Residual Stress ◽

Phase Separation ◽

Elevated Temperatures ◽

High Energy ◽

Film Plane ◽

X Rays ◽

X Ray Diffraction ◽

Synchrotron Source ◽

Simultaneous Acquisition ◽

Initial Stage

Residual stresses and microstructural changes during phase separation in Ti33Al67N coatings were examined using microfocused high energy x-rays from a synchrotron source. The transmission geometry allowed simultaneous acquisition of x-ray diffraction data over 360° and revealed that the decomposition at elevated temperatures occurred anisotropically, initiating preferentially along the film plane. The as-deposited compressive residual stress in the film plane first relaxed with annealing, before dramatically increasing concurrently with the initial stage of phase separation where metastable, nm-scale c-AlN platelets precipitated along the film direction. These findings were further supported from SAXS analyses.

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