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

Author(s):  
Roman Schlem ◽  
Michael Ghidiu ◽  
Sean Culver ◽  
Anna-Lena Hansen ◽  
Wolfgang Zeier

<p>The lithium argyrodites Li<sub>6</sub>PS<sub>5</sub>X (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 Li<sub>6</sub>PS<sub>5</sub>I (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.</p><p>Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li<sub>6</sub>PS<sub>5-<i>x</i></sub>Se<i><sub>x</sub></i>I. 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 S<sup>2-</sup>with Se<sup>2- </sup>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. </p>

2019 ◽  
Author(s):  
Roman Schlem ◽  
Michael Ghidiu ◽  
Sean Culver ◽  
Anna-Lena Hansen ◽  
Wolfgang Zeier

<p>The lithium argyrodites Li<sub>6</sub>PS<sub>5</sub>X (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 Li<sub>6</sub>PS<sub>5</sub>I (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.</p><p>Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li<sub>6</sub>PS<sub>5-<i>x</i></sub>Se<i><sub>x</sub></i>I. 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 S<sup>2-</sup>with Se<sup>2- </sup>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. </p>


2019 ◽  
Author(s):  
Roman Schlem ◽  
Michael Ghidiu ◽  
Sean Culver ◽  
Anna-Lena Hansen ◽  
Wolfgang Zeier

<p>The lithium argyrodites Li<sub>6</sub>PS<sub>5</sub>X (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 Li<sub>6</sub>PS<sub>5</sub>I (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.</p><p>Here we explore the influence of isoelectronic substitution of sulfur with selenium in Li<sub>6</sub>PS<sub>5-<i>x</i></sub>Se<i><sub>x</sub></i>I. 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 S<sup>2-</sup>with Se<sup>2- </sup>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. </p>


2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>


2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>


2016 ◽  
Vol 698 ◽  
pp. 8-12 ◽  
Author(s):  
Shinichi Furusawa ◽  
Yohei Minami

In this study, KAlSi3O8 was synthesized by a solid-phase reaction at 900, 1000 and 1100 °C, using K2CO3, Al2O3 and SiO2 as the starting materials. The powder X-ray diffraction profile of the compound thus prepared was confirmed to contain a mixture of crystalline and glass phases. In addition, a higher sintering temperature of greater than 1000 °C possibly led to the decrease in the crystalline phase. From the temperature dependence of dc conductivity, activation energies for ionic transport were estimated to be 0.79–0.84 eV. The frequency-dependence of the real part of electrical conductivity suggests that the mechanism of ionic transport in the dispersion region possibly depends on the crystallinity of KAlSi3O8.


2019 ◽  
Author(s):  
Till Fuchs ◽  
Sean Culver ◽  
Paul Till ◽  
Wolfgang Zeier

<p>The sodium-ion conducting family of Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, with <i>Pn</i> = P, Sb, have gained interest for the use in solid-state batteries due to their high ionic conductivity. However, significant improvements to the conductivity have been hampered by the lack of aliovalent dopants that can introduce vacancies into the structure. Inspired by the need for vacancy introduction into Na<sub>3</sub><i>Pn</i>S<sub>4</sub>, the solid solutions with WS<sub>4</sub><sup>2-</sup> introduction are explored. The influence of the substitution with WS<sub>4</sub><sup>2-</sup> for PS<sub>4</sub><sup>3-</sup> and SbS<sub>4</sub><sup>3-</sup>, respectively, is monitored using a combination of X-ray diffraction, Raman and impedance spectroscopy. With increasing vacancy concentration improvements resulting in a very high ionic conductivity of 13 ± 3 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>P<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> and 41 ± 8 mS·cm<sup>-1</sup> for Na<sub>2.9</sub>Sb<sub>0.9</sub>W<sub>0.1</sub>S<sub>4</sub> can be observed. This work acts as a stepping-stone towards further engineering of ionic conductors using vacancy-injection via aliovalent substituents.</p>


2019 ◽  
Vol 55 (75) ◽  
pp. 11223-11226 ◽  
Author(s):  
Timo Bartsch ◽  
A-Young Kim ◽  
Florian Strauss ◽  
Lea de Biasi ◽  
Jun Hao Teo ◽  
...  

Ex situ and operando X-ray diffraction allows determining the state-of-charge of all-solid-state batteries in an indirect manner.


2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 724
Author(s):  
Sara Massardo ◽  
Alessandro Cingolani ◽  
Cristina Artini

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2949
Author(s):  
Marzieh Rabiei ◽  
Arvydas Palevicius ◽  
Amir Dashti ◽  
Sohrab Nasiri ◽  
Ahmad Monshi ◽  
...  

Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffraction; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is performed for the validation of the novelty assumptions.


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