On the Local Charge Inhomogeneity and Lithium Distribution in the Superionic Argyrodites Li6PS5X (X = Cl, Br, I)

The lithium-argyrodites Li6PS5X (X = Cl, Br, I) exhibit high lithium-ion conductivities, making them promising candidates for use in solid-state batteries. These solid electrolytes can show considerable substitutional X−/S2− anion-disorder, with greater disorder typically correlated with higher lithium-ion conductivities. The atomic-scale effects of this anion site-disorder within the host lattice—in particular how lattice disorder modulates the lithium substructure—are not well understood. Here, we characterize the lithium substructure in Li6PS5X (X = Cl, Br, I) as a function of temperature and anion site-disorder, using Rietveld refinements against temperature-dependent neutron diffraction data. Analysis of these high-resolution diffraction data reveals an additional lithium position previously unreported for Li6PS5Xargyrodites, suggesting that the lithium conduction pathway in these materials differs from the most common model proposed in earlier studies. Analysis of the Li+ positions and their radial distributions reveals that greater inhomogeneityof the local anionic charge, due to X−/S2− site-disorder, is associated with more spatially-diffuse lithium distributions. This observed coupling of site-disorder and lithium distribution provides a possible explanation for the enhanced lithium transport in anion-disordered lithium argyrodites, and highlights the complex interplay between anion configuration and lithium substructure in this family of superionic conductors.

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On the Local Charge Inhomogeneity and Lithium Distribution in the Superionic Argyrodites Li6PS5X (X = Cl, Br, I)

10.26434/chemrxiv.12360722.v1 ◽

2020 ◽

Author(s):

Nicolo Minafra ◽

Marvin Kraft ◽

Tim Bernges ◽

Cheng Li ◽

Roman Schlem ◽

...

Keyword(s):

Diffraction Data ◽

Scale Effects ◽

Lithium Ion ◽

Host Lattice ◽

Atomic Scale ◽

Superionic Conductors ◽

Ion Conductivities ◽

Conduction Pathway ◽

Site Disorder ◽

Anion Site

The lithium-argyrodites Li6PS5X (X = Cl, Br, I) exhibit high lithium-ion conductivities, making them promising candidates for use in solid-state batteries. These solid electrolytes can show considerable substitutional X−/S2− anion-disorder, with greater disorder typically correlated with higher lithium-ion conductivities. The atomic-scale effects of this anion site-disorder within the host lattice—in particular how lattice disorder modulates the lithium substructure—are not well understood. Here, we characterize the lithium substructure in Li6PS5X (X = Cl, Br, I) as a function of temperature and anion site-disorder, using Rietveld refinements against temperature-dependent neutron diffraction data. Analysis of these high-resolution diffraction data reveals an additional lithium position previously unreported for Li6PS5Xargyrodites, suggesting that the lithium conduction pathway in these materials differs from the most common model proposed in earlier studies. Analysis of the Li+ positions and their radial distributions reveals that greater inhomogeneityof the local anionic charge, due to X−/S2− site-disorder, is associated with more spatially-diffuse lithium distributions. This observed coupling of site-disorder and lithium distribution provides a possible explanation for the enhanced lithium transport in anion-disordered lithium argyrodites, and highlights the complex interplay between anion configuration and lithium substructure in this family of superionic conductors.

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Synergistic O2-/Li+ Dual Ion Transportation at Atomic Scale

Research ◽

10.34133/2019/9087386 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

F. Q. Meng ◽

Q. H. Zhang ◽

A. Gao ◽

X. Z. Liu ◽

J. N. Zhang ◽

...

Keyword(s):

Lithium Ion ◽

Vertical Displacement ◽

Host Lattice ◽

Electrochemical Process ◽

Atomic Scale ◽

Ion Migration ◽

Transmission Electron ◽

Oxygen Anions ◽

Lithium Ion Conductors ◽

Electrical Bias

The ion migration during electrochemical process is a fundamental scientific issue for phase transition behavior and of technical importance for various functional devices, where cations or anions are active under electrical bias. Usually only one type of functional ion, O2- or Li+, is activated due to their different migration energy barriers, cooperated by the valence change of other immobile ions in the host lattice matrix, e.g., Co2+/Co3+ and Mn3+/Mn4+ redox couples, owing to the charge neutralization. Here we select spinel Li4Ti5O12 as anode and construct an all-solid-state battery under a transmission electron microscope; a synergistic transportation of O2- and Li+ driven by an electrical bias was directly observed at the atomic scale. A small amount of oxygen anions was extracted firstly as a result of its lowest vacancy formation energy under 2.2 V, leading to the vertical displacement of oxygen. Up to 2.7 V, an ordered phase with both Li- and O- deficiency formed. The Li+ and O2- ions are simultaneously extracted out from the [LiO4] tetrahedra due to the electroneutrality principle. The migration paths of O and Li have been proposed and verified by first-principles calculations. These results reveal a brand new synergistic ion migration manner and may provide up-to-date insights on the transportation process of lithium ion conductors.

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Synergistic O2-/Li+ Dual Ion Transportation at Atomic Scale

Research ◽

10.1155/2019/9087386 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

F. Q. Meng ◽

Q. H. Zhang ◽

A. Gao ◽

X. Z. Liu ◽

J. N. Zhang ◽

...

Keyword(s):

Lithium Ion ◽

Vertical Displacement ◽

Host Lattice ◽

Electrochemical Process ◽

Atomic Scale ◽

Ion Migration ◽

Transmission Electron ◽

Oxygen Anions ◽

Lithium Ion Conductors ◽

Electrical Bias

The ion migration during electrochemical process is a fundamental scientific issue for phase transition behavior and of technical importance for various functional devices, where cations or anions are active under electrical bias. Usually only one type of functional ion, O2- or Li+, is activated due to their different migration energy barriers, cooperated by the valence change of other immobile ions in the host lattice matrix, e.g., Co2+/Co3+ and Mn3+/Mn4+ redox couples, owing to the charge neutralization. Here we select spinel Li4Ti5O12 as anode and construct an all-solid-state battery under a transmission electron microscope; a synergistic transportation of O2- and Li+ driven by an electrical bias was directly observed at the atomic scale. A small amount of oxygen anions was extracted firstly as a result of its lowest vacancy formation energy under 2.2 V, leading to the vertical displacement of oxygen. Up to 2.7 V, an ordered phase with both Li- and O- deficiency formed. The Li+ and O2- ions are simultaneously extracted out from the [LiO4] tetrahedra due to the electroneutrality principle. The migration paths of O and Li have been proposed and verified by first-principles calculations. These results reveal a brand new synergistic ion migration manner and may provide up-to-date insights on the transportation process of lithium ion conductors.

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

10.26434/chemrxiv.9794588 ◽

2019 ◽

Author(s):

Ajay Gautam ◽

Marcel Sadowski ◽

Nils Prinz ◽

Henrik Eickhoff ◽

Nicolo Minafra ◽

...

Keyword(s):

Elevated Temperatures ◽

Synthesis Method ◽

Reaction Times ◽

Ionic Conductivities ◽

Ionic Transport ◽

High Energy ◽

Superionic Conductors ◽

Rapid Crystallization ◽

Site Disorder ◽

Fast Cooling

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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Resolving atomic-scale phase transformation and oxygen loss mechanism in ultrahigh-nickel layered cathodes for cobalt-free lithium-ion batteries

Matter ◽

10.1016/j.matt.2021.03.012 ◽

2021 ◽

Author(s):

Chunyang Wang ◽

Lili Han ◽

Rui Zhang ◽

Hao Cheng ◽

Linqin Mu ◽

...

Keyword(s):

Phase Transformation ◽

Lithium Ion Batteries ◽

Lithium Ion ◽

Atomic Scale ◽

Loss Mechanism ◽

Oxygen Loss ◽

Layered Cathodes

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Atomic scale effects of zirconium and hafnium incorporation at a model silicon/silicate interface by first principles calculations

IEEE Electron Device Letters ◽

10.1109/55.892429 ◽

2001 ◽

Vol 22 (1) ◽

pp. 14-16 ◽

Cited By ~ 45

Author(s):

A. Kawamoto ◽

J. Jameson ◽

P. Griffin ◽

Kyeongjae Cho ◽

R. Dutton

Keyword(s):

First Principles ◽

Scale Effects ◽

Atomic Scale ◽

First Principles Calculations

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Spin dependent recombination study of the atomic-scale effects of fluorine on the negative bias temperature instability

2009 IEEE International Reliability Physics Symposium ◽

10.1109/irps.2009.5173396 ◽

2009 ◽

Cited By ~ 2

Author(s):

J.T. Ryan ◽

P.M. Lenahan ◽

A.T. Krishnan ◽

S. Krishnan ◽

J.P. Campbell

Keyword(s):

Scale Effects ◽

Atomic Scale ◽

Negative Bias ◽

Negative Bias Temperature Instability ◽

Temperature Instability ◽

Bias Temperature Instability

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Ionic Conduction Through Reaction Products at the Electrolyte/electrode Interface in All-Solid-State Li⁺ Batteries

10.26434/chemrxiv.13003952.v1 ◽

2020 ◽

Author(s):

Chuhong Wang ◽

Koutarou Aoyagi ◽

Muratahan Aykol ◽

Tim Mueller

Keyword(s):

Solid State ◽

Lithium Ion Batteries ◽

Ionic Conduction ◽

Lithium Ion ◽

Interatomic Potentials ◽

Reaction Products ◽

Ion Diffusion ◽

Ion Conductivities ◽

Common Electrode ◽

Growth Limits

The development of all-solid-state lithium ion batteries has been hindered by the formation of a poorly conductive interphase at the interface between electrode and electrolyte materials. In the manuscript, we shed light on this problem by computationally evaluating potential lithium ion diffusion pathways through metastable arrangements of product phases that can form at 56 interfaces between common electrode and electrolyte materials. The evaluation of lithium-ion conductivities in the product phases is made possible by the use of machine-learned interatomic potentials trained on the fly. We identify likely reasons for the degradation of solid-state battery performance and discuss how these problems could be mitigated. These results provide enhanced understanding of how interface impedance growth limits the performance of all-solid-state lithium-ion batteries.

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