Search

Your search keyword '"Sakuda, Atsushi"' showing total 525 results
Start Over Author "Sakuda, Atsushi"
525 results on '"Sakuda, Atsushi"'

111. Unique Li deposition behavior in Li3PS4 solid electrolyte observed via operando X-ray computed tomography.

Author

Park, Jaehee, Watanabe, Toshiki, Yamamoto, Kentaro, Uchiyama, Tomoki, Takami, Tsuyoshi, Sakuda, Atsushi, Hayashi, Akitoshi, Tatsumisago, Masahiro, and Uchimoto, Yoshiharu

Subjects
COMPUTED tomography, SOLID electrolytes, SUPERIONIC conductors, IONIC conductivity, LITHIUM, X-rays
Abstract

The problem of lithium dendrites must be addressed for practical lithium metal all-solid-state batteries. Herein, three-dimensional morphological changes within Li3PS4 electrolyte away from the anode were observed using operando X-ray computed tomography. We revealed that the electronic conduction of decomposition and the electrolyte/void interface cause the lithium deposition within the Li3PS4. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

113. Twinned single crystal structure of Li4P2S6.

Author

Ben Yahia, Hamdi, Motohashi, Kota, Mori, Shigeo, Sakuda, Atsushi, and Hayashi, Akitoshi

Subjects
CRYSTAL structure, SINGLE crystals, SPACE groups, UNIT cell, TWINNING (Crystallography)
Abstract

Yellow needles-like single crystals of Li4P2S6 were obtained serendipitously during the preparation of Li7P3S10O. The twinned crystal structure of Li4P2S6 was determined from single-crystal X-ray diffraction data [wR(F2) = 0.069, 716 reflections, 40 variables]. Li4P2S6 crystallizes in the trigonal system, space group P 3 ‾ m 1 (N° 164), a = 10.5042(8) Å, c = 6.5837(6) Å, V = 629.11(9) Å3 and Z = 2. The lithium octahedra form a [Li4S6]8− honeycomb-like structure within which diphosphate units are located. The comparison of our crystal structure to those of P63/mcm-, P 3 ‾ 1 m -, and P321-Li4P2S6 demonstrated group-subgroup relationships and associated the disorder or order of the phosphorus atoms within the identical [Li4S6]8− 3d-frameworks to the choice of the unit cell (the subcell with a ∼ 6.07 Å vs. the supercell with a ∼ 10.5 Å). [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

115. Mechanochemical Synthesis and Characterization of K2+xZr1–xYxCl6: Potassium-Ion-Conducting Chloride

Author

Okada, Yuya, Nasu, Akira, Kimura, Takuya, Tsukasaki, Hirofumi, Mori, Shigeo, Ben Yahia, Hamdi, Motohashi, Kota, Sakuda, Atsushi, and Hayashi, Akitoshi

Abstract

K-ion batteries are attracting attention as rechargeable batteries following Li-ion and Na-ion batteries. However, their safety is of concern owing to the use of organic electrolytes. The use of solid electrolytes instead of organic electrolytes can resolve this problem. Chloride solid electrolytes have attracted attention in recent years as Li- and Na-ion conductors, but reports on chloride K-ion conductors have been scarce. In this study, new K-ion-conducting chlorides, K2+xZr1–xYxCl6(x= 0–1), were prepared by a mechanochemical method. The X-ray powder diffraction (XRPD) patterns of the prepared solid electrolytes exhibited broad Bragg peaks, and the high-resolution transmission electron microscopy observations revealed the presence of nanocrystals dispersed in amorphous matrixes. New crystalline phases, closely related to monoclinic K2TeCl6, were precipitated in the K2+xZr1–xYxCl6matrixes at x= 0–0.4. The Rietveld refinements of the XRPD patterns for the new phases revealed that the excess of K, introduced by Y substitution, occupied the vacant B′ octahedral site of the cation-deficient double perovskite A2BB′X6structure. The conductivity at 25 °C of the K2+xZr1–xYxCl6chlorides exceeded 10–7S cm–1at x= 0–0.4, and a maximum conductivity of 9.2 × 10–7S cm–1was achieved at x= 0.3. Heat treatment above 400 °C of the K2+xZr1–xYxCl6electrolyte with x= 0.3 resulted in crystallization of the amorphous components, decomposition of the phase into a mixture of K2ZrCl6and K3YCl6, and a decrease of the ionic conductivity. In addition to the K concentration and crystalline phase in the electrolytes, the amorphous components also play a key role in the high ionic conductivity of the K2+xZr1–xYxCl6chlorides.

Published
2023
Full Text
View/download PDF

116. Mechanochemical Synthesis and Structure of the Alkali Metal Magnesium Chalcogenide Na6MgS4

Author

Ben Yahia, Hamdi, Motohashi, Kota, Sakuda, Atsushi, and Hayashi, Akitoshi

Abstract

The new binary sodium magnesium sulfide was prepared by the mechanochemical synthesis route from Na2S and MgS as starting materials. Na6MgS4is extremely sensitive and partially decomposes in the presence of oxygen traces. With the use of an excess of MgS in the milling process, the molar ratio of the impurities was successfully decreased from 38% (Na2S + MgO) to 13% MgO. The crystal structure and properties were characterized by X-ray powder diffraction, thermogravimetry/differential thermal analysis, scanning electron microscopy–energy-dispersive X-ray spectroscopy, and electrochemical impedance spectroscopy. The Rietveld refinement confirmed that Na6MgS4is isostructural to Na6ZnO4. The compound crystallized in the hexagonal system in the non-centro-symmetric space group P63mc(No. 186) with a= 9.0265(1), c= 6.9524(1) Å, V= 490.58(1) Å3, and Z= 2. The structure consisted of a wurtzite-like 3D framework built up of corner-sharing MgS4and NaS4tetrahedra, with 3/4 of the tunnels, parallel to the caxis, filled with octahedrally coordinated sodium atoms. The ionic conductivity of the composite material (87% Na6MgS4+ 13% MgO) being low (4.4 × 10–8S cm–1with Ea= 0.56 eV), indium-doped samples Na6–x□xMg1–xInxS4(x= 0.05, 0.1) were prepared by the mechanochemical synthesis route. These samples also contained 13% MgO. Their ionic conductivities of 9.3 × 10–8S cm–1(Ea= 0.51 eV) and 2.5 × 10–7S cm–1(Ea= 0.49 eV) at 25 °C for x= 0.05 and 0.1, respectively, were higher than the ionic conductivity of the undoped sample.

Published
2023
Full Text
View/download PDF

125. AC Impedance Analysis of the Degeneration and Recovery of Argyrodite Sulfide-Based Solid Electrolytes under Dry-Room-Simulated Condition

Author

SANO, Hikaru, primary, MORINO, Yusuke, additional, YABUKI, Akinori, additional, SATO, Shimpei, additional, ITAYAMA, Naohiko, additional, MATSUMURA, Yasuyuki, additional, IWASAKI, Masahiro, additional, TAKEHARA, Masahiro, additional, ABE, Takeshi, additional, ISHIGURO, Yasuo, additional, TAKAHASHI, Tsukasa, additional, MIYASHITA, Norihiko, additional, SAKUDA, Atsushi, additional, and HAYASHI, Akitoshi, additional

Published
2022
Full Text
View/download PDF

128. Synthesis of an AlI3-doped Li2S positive electrode with superior performance in all-solid-state batteries

Author

Gamo, Hirotada, primary, Maeda, Takaki, additional, Hikima, Kazuhiro, additional, Deguchi, Minako, additional, Fujita, Yushi, additional, Kawasaki, Yusuke, additional, Sakuda, Atsushi, additional, Muto, Hiroyuki, additional, Phuc, Nguyen Huu Huy, additional, Hayashi, Akitoshi, additional, Tatsumisago, Masahiro, additional, and Matsuda, Atsunori, additional

Published
2022
Full Text
View/download PDF

129. Tin Interlayer at the Li/Li3PS4Interface for Improved Li Stripping/Plating Performance

Author

Inaoka, Takeaki, Asakura, Taichi, Otoyama, Misae, Motohashi, Kota, Sakuda, Atsushi, Tatsumisago, Masahiro, and Hayashi, Akitoshi

Abstract

Li metal is a promising negative electrode material for the development of all-solid-state batteries with high energy densities. However, the short-circuiting of batteries owing to Li dendrite formation is challenging. To solve this issue, it is crucial to form a suitable interface between the Li metal and solid electrolyte. This study demonstrates that the incorporation of a Sn interlayer at the interface between the Li metal and Li3PS4(LPS) electrolyte improved the Li stripping/plating performance of all-solid-state Li symmetrical cells. The cycling performance was further enhanced by replacing pure Li metal with a Li–Mg alloy. Galvanostatic cycling tests were conducted on a symmetrical cell of Li–Mg/Sn/LPS/Sn/Li–Mg at a current density of 1.0 mA cm–2and a temperature of 100 °C. The operation of the cell was stable for 5000 h without short-circuiting. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that Sn film incorporation into the Li or Li–Mg/LPS interface suppressed the reductive LPS decomposition and maintained a stable interface. These findings will facilitate the development of interfacial modifications between Li metal and sulfide solid electrolytes to enhance the cycling performance of all-solid-state Li metal batteries.

Published
2023
Full Text
View/download PDF

134. Crystallization behaviors in superionic conductor Na3PS4

Author

Nakajima, Hiroshi, primary, Tsukasaki, Hirofumi, additional, Ding, Jiong, additional, Kimura, Takuya, additional, Nakano, Takumi, additional, Nasu, Akira, additional, Hirata, Akihiko, additional, Sakuda, Atsushi, additional, Hayashi, Akitoshi, additional, and Mori, Shigeo, additional

Published
2021
Full Text
View/download PDF

136. Crystalline precursor derived from Li3PS4 and ethylenediamine for ionic conductors.

Author

Kimura, Takuya, Ito, Akane, Nakano, Takumi, Hotehama, Chie, Kowada, Hiroe, Sakuda, Atsushi, Tatsumisago, Masahiro, and Hayashi, Akitoshi

Abstract

Liquid-phase syntheses of sulfide materials are attractive for the mass production of solid electrolytes for all-solid-state batteries. In liquid-phase synthesis, the precursor of the solid electrolyte is obtained. The precursors are important for producing electrolytes of the same quality because they decompose into electrolytes by heat treatment. However, only a few studies have focused on the formation mechanism and structure of precursors. This study proposes a formation mechanism for Li3PS4 during liquid-phase synthesis using ethylenediamine (EDA) as a solvent and clarifies the crystal structure of Li3PS4·NH2CH2CH2NH2 (Li3PS4·EDA). Raman spectroscopy and nuclear magnetic resonance revealed that intermediate P2S62− units were generated in the EDA solution. Crystal structure analysis of Li3PS4·EDA showed that the terminal nitrogen atom of EDA coordinates with two lithium atoms. Ionic conductivity of Li3PS4·EDA was 2.8 × 10−9 S cm−1 at 25 °C. The analysis of precursors of solid electrolytes provides insight into the behavior of solvent molecules as ligands in the synthesis of sulfide electrolytes. Highlights: β-Li3PS4 is prepared using a precursor obtained from Li3PS4 and ethylenediamine. Intermediate P2S62− units are generated in the ethylenediamine solution. Tetrahedra of PS4 and LiS4 form a framework in the precursor. Ethylenediamine molecules coordinate to two lithium cations in the precursor. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

147. Hydration and Dehydration Behavior of Li4SnS4for Applications as a Moisture-Resistant All-Solid-State Battery Electrolyte

Author

Kimura, Takuya, Nakano, Takumi, Sakuda, Atsushi, Tatsumisago, Masahiro, and Hayashi, Akitoshi

Abstract

All-solid-state batteries are promising energy storage devices owing to their high safety and energy density. Sulfide-based solid electrolytes have high ionic conductivities and are ductile. Although sulfide electrolytes are candidates for all-solid-state batteries, they are moisture-sensitive. Li4SnS4electrolytes can overcome some of these weaknesses and show the suppressed evolution of H2S gas in a humid environment. However, the suppression mechanism is unclear, making the design of moisture-resistant sulfide electrolytes challenging. Therefore, we investigated the structural changes of Li4SnS4in humid N2. X-ray structural analysis revealed that Li4SnS4was hydrated to Li4SnS4·4H2O without generating H2S gas. Furthermore, the hydrate could be reversibly dehydrated by heat treatment to the original sulfide, suggesting that the formation of stable hydrates suppresses the generation of H2S gas. These findings will aid in the design of moisture-resistant sulfide materials.

Published
2023
Full Text
View/download PDF

150. Investigation of the Suppression of Dendritic Lithium Growth with a Lithium-Iodide-Containing Solid Electrolyte

Author

Takahashi, Masakuni, primary, Watanabe, Toshiki, additional, Yamamoto, Kentaro, additional, Ohara, Koji, additional, Sakuda, Atsushi, additional, Kimura, Takuya, additional, Yang, Seunghoon, additional, Nakanishi, Koji, additional, Uchiyama, Tomoki, additional, Kimura, Masao, additional, Hayashi, Akitoshi, additional, Tatsumisago, Masahiro, additional, and Uchimoto, Yoshiharu, additional

Published
2021
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results