Nonlinear material and ionic transport through membrane nanotubes

Sulfidic sodium ion conductors are currently investigated for the possible use in all-solid-state sodium ion batteries. The design of high performing electrolytes in terms of temperature-dependent ionic transport is based upon the fundamental understanding of structure – transport relationships within the given structural phase boundaries inherent to the investigated materials class. In this work, the Na+ superionic structural family of Na11Sn2PS12 is explored by using the systematic antimony substitution with phosphorous in Na11+xSn2+x(Sb1-yPy)1-xS12. A combination of Rietveld refinements against X-ray synchrotron diffraction data with electrochemical impedance spectroscopy is used to monitor the changes in the anionic framework, the Na+ substructure and the ionic transport. A new simplified descriptor for the average Na+ diffusion pathways, the average Na+ polyhedral volume is introduced, which is used to correlate the contraction of the overall lattice and the found activation barriers in the system. This study exemplifies how substitution affects diffusion pathways in ionic conductors and widens the knowledge about the related structural motifs and their influence on the ionic transport in this novel class of ionic conductors.

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Changing the Static and Dynamic Lattice Effects for the Improvement of the Ionic Transport Properties Within the Argyrodite Li6PS5-xSexI

10.26434/chemrxiv.9807770.v1 ◽

2019 ◽

Author(s):

Roman Schlem ◽

Michael Ghidiu ◽

Sean Culver ◽

Anna-Lena Hansen ◽

Wolfgang Zeier

Keyword(s):

Ionic Conductivity ◽

Activation Barrier ◽

Parent Compound ◽

Ionic Transport ◽

X Ray Diffraction ◽

X Ray ◽

Lattice Effects ◽

Solid State Batteries ◽

All Solid State Batteries ◽

Pulse Echo

The lithium argyrodites Li6PS5X (X = Cl, Br, I) have been gaining momentum as candidates for electrolytes in all-solid-state batteries. While these materials have been well-characterized structurally, the influences of the static and dynamic lattice properties are not fully understood. Recent improvements to the ionic conductivity of Li6PS5I (which as a parent compound is a poor ionic conductor) via elemental substitutions have shown that a multitude of influences affect the ionic transport in the lithium argyrodites, and that even poor conductors in this class have room left for improvement.Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li6PS5-xSexI. Using a combination of X-ray diffraction, impedance spectroscopy, Raman spectroscopy, and pulse-echo speed of sound measurements,we explore the influence of the static and dynamic lattice on the ionic transport. The substitution of S2-with Se2- broadens the diffusion pathways and structural bottlenecks, as well as leading to a softer more polarizable lattice, all of which lower the activation barrier and lead to an increase in the ionic conductivity. This work sheds light on ways to systematically understand and improve the functional properties of this exciting material family.

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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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Ionic Transport, Defects and Electrooptical Response of Perovskite Solar Cells

10.29363/nanoge.fallmeeting.2018.059 ◽

2018 ◽

Author(s):

Juan Bisquert

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Ionic Transport ◽

Electrooptical Response

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Faculty Opinions recommendation of Membrane nanotubes physically connect T cells over long distances presenting a novel route for HIV-1 transmission.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1101195.557198 ◽

2008 ◽

Author(s):

Volker Haucke

Keyword(s):

T Cells ◽

Membrane Nanotubes ◽

Hiv 1

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Failure Analysis of Apennine Masonry Churches Severely Damaged during the 2016 Central Italy Seismic Sequence

Buildings ◽

10.3390/buildings11020058 ◽

2021 ◽

Vol 11 (2) ◽

pp. 58 ◽

Cited By ~ 2

Author(s):

Francesco Clementi

Keyword(s):

Case Studies ◽

Central Italy ◽

Numerical Data ◽

Sensitivity Study ◽

Nonlinear Material ◽

Seismic Sequence ◽

Nonlinear Approach ◽

Nonlinear Static ◽

Masonry Churches ◽

Global And Local

This paper presents a detailed study of the damages and collapses suffered by various masonry churches in the aftermath of the seismic sequence of Central Italy in 2016. The damages will first be analyzed and then compared with the numerical data obtained through 3D simulations with eigenfrequency and then nonlinear static analyses (i.e., pushover). The main purposes of this study are: (i) to create an adequately consistent sensitivity study on several definite case studies to obtain an insight into the role played by geometry—which is always unique when referred to churches—and by irregularities; (ii) validate or address the applicability limits of the more widespread nonlinear approach, widely recommended by the Italian Technical Regulations. Pushover analyses are conducted assuming that the masonry behaves as a nonlinear material with different tensile and compressive strengths. The consistent number of case studies investigated will show how conventional static approaches can identify, albeit in a qualitative way, the most critical macro-elements that usually trigger both global and local collapses, underlining once again how the phenomena are affected by the geometry of stones and bricks, the texture of the wall face, and irregularities in the plan and elevation and in addition to hypotheses made on the continuity between orthogonal walls.

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Vibrations of Nonlinear Elastic Structure Excited by Compressible Flow

Applied Sciences ◽

10.3390/app11114748 ◽

2021 ◽

Vol 11 (11) ◽

pp. 4748

Author(s):

Monika Balázsová ◽

Miloslav Feistauer ◽

Jaromír Horáček ◽

Adam Kosík

Keyword(s):

Compressible Flow ◽

Nonlinear Elasticity ◽

Vocal Tract ◽

Stokes Equations ◽

Vocal Folds ◽

Nonlinear Material ◽

Navier Stokes ◽

Arbitrary Lagrangian Eulerian ◽

Navier Stokes Equations ◽

Reliable Solution

This study deals with the development of an accurate, efficient and robust method for the numerical solution of the interaction of compressible flow and nonlinear dynamic elasticity. This problem requires the reliable solution of flow in time-dependent domains and the solution of deformations of elastic bodies formed by several materials with complicated geometry depending on time. In this paper, the fluid–structure interaction (FSI) problem is solved numerically by the space-time discontinuous Galerkin method (STDGM). In the case of compressible flow, we use the compressible Navier–Stokes equations formulated by the arbitrary Lagrangian–Eulerian (ALE) method. The elasticity problem uses the non-stationary formulation of the dynamic system using the St. Venant–Kirchhoff and neo-Hookean models. The STDGM for the nonlinear elasticity is tested on the Hron–Turek benchmark. The main novelty of the study is the numerical simulation of the nonlinear vocal fold vibrations excited by the compressible airflow coming from the trachea to the simplified model of the vocal tract. The computations show that the nonlinear elasticity model of the vocal folds is needed in order to obtain substantially higher accuracy of the computed vocal folds deformation than for the linear elasticity model. Moreover, the numerical simulations showed that the differences between the two considered nonlinear material models are very small.

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