The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Masahiro Tatsumisago - One of the best experts on this subject based on the ideXlab platform.
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evaluation of mechanical properties of na2s p2s5 Sulfide Glass electrolytes
Journal of Materials Chemistry, 2015Co-Authors: Masashi Nose, Akitoshi Hayashi, Atsutaka Kato, Atsushi Sakuda, Masahiro TatsumisagoAbstract:Mechanical properties such as formability and elastic moduli of solid electrolytes are important for the fabrication of all-solid-state batteries and retention of their charge–discharge capacities. In this paper, xNa2S·(100 − x)P2S5 (mol%) Sulfide Glass electrolytes (x = 50, 67, and 75) were prepared and their formability and elastic moduli were evaluated by an ultrasonic pulse-echo technique and a compression test under uniaxial pressing. The Glasses were better densified and showed lower Young's moduli (15–19 GPa) than the Li2S–P2S5 Glasses.
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Sulfide Glass ceramic electrolytes for all solid state lithium and sodium batteries
International Journal of Applied Glass Science, 2014Co-Authors: Masahiro Tatsumisago, Akitoshi HayashiAbstract:Sulfide Glass-ceramic electrolytes with Li+ or Na+ ion conduction have been developed in last decade. High-temperature phases of Li7P3S11 and cubic Na3PS4 are precipitated from mother Glasses, and the obtained Glass-ceramics show higher conductivity than the mother Glasses. It is difficult to synthesize those high-temperature phases by conventional solid-state reaction, and Glass electrolytes are thus important as a precursor for forming high-temperature phases. The highest conductivities at 25°C of 1.1 × 10−2 S/cm for Li+ ion conductor (Li7P3S11) and 7.4 × 10−4 S/cm for Na+ ion conductor (Na3.06P0.94Si0.06S4) are achieved in Sulfide Glass-ceramic electrolytes. All-solid-state batteries with Sulfide Glass-ceramic electrolytes were fabricated by cold press at room temperature. Sulfide electrolytes have favorable mechanical properties to form favorable solid–solid contacts in solid-state batteries by pressing without heat treatment. All-solid-state Li-In/S and Na-Sn/TiS2 cells using Sulfide Glass-ceramic electrolytes operate as secondary batteries and exhibit good cycle performance at room temperature.
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Invited paper: Recent development of bulk-type solid-state rechargeable lithium batteries with Sulfide Glass-ceramic electrolytes
Electronic Materials Letters, 2012Co-Authors: Akitoshi Hayashi, Masahiro TatsumisagoAbstract:The recent development of bulk-type solid-state rechargeable lithium batteries with Sulfide Glass-ceramics as a solid electrolyte was reviewed. Sulfide Glasses and Glass-ceramics in the system Li2S-P2S5 have an advantage of high conductivity, wide electrochemical window and low grain-boundary resistance. Bulk-type solid-state batteries composed of compressed powder layers of electrode and electrolyte were fabricated with Li2S-P2S5 Glass-ceramic electrolytes. Formation of a favorable solid-solid interface between electrode and electrolyte is a key to achieving excellent performance in solid-state batteries. The mechanochemical preparation of nanocomposite electrodes and surface modification of active materials by softening of the electrolyte, or PLD coating, were useful for increasing the electrode-electrolyte contact area and improving battery performance.
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Development of Sulfide Glass-ceramic electrolytes for all-solid-state lithium rechargeable batteries
Journal of Solid State Electrochemistry, 2010Co-Authors: Akitoshi Hayashi, Keiichi Minami, Masahiro TatsumisagoAbstract:Development of Li_2S–P_2S_5-based Glass-ceramic electrolytes is reviewed. Superionic crystals of Li_7P_3S_11 and Li_3.25P_0.95S_4 were precipitated from the Li_2S–P_2S_5 Glasses at the selected compositions. These high temperature or metastable phases enhanced conductivity of Glass ceramics up to over 10^−3 S cm^−1 at room temperature. The original (or mother) Glass electrolytes itself showed somewhat lower conductivity of 10^−4 S cm^−1 and have important role as a precursor for obtaining the superionic crystals, which were not synthesized by a conventional solid-state reaction. The substitution of P_2O_5 for P_2S_5 at the composition 70Li_2S·30P_2S_5 (mol%) improved both conductivity and electrochemical stability of Glass-ceramic electrolytes. The all-solid-state In/LiCoO_2 cell using the 70Li_2S·27P_2S_5·3P_2O_5 (mol%) Glass-ceramic electrolyte showed initial capacity of 105 mAh g^−1 (gram of LiCoO_2) at the current density of 0.13 mA cm^−2 and exhibited higher electrochemical performance than that using the 70Li_2S·30P_2S_5 Glass-ceramic electrolyte.
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high lithium ion conduction of Sulfide Glass based solid electrolytes and their application to all solid state batteries
Journal of Non-crystalline Solids, 2009Co-Authors: Akitoshi Hayashi, Keiichi Minami, Masahiro TatsumisagoAbstract:Abstract Sulfide Glass-based solid electrolytes prepared by melt quenching and mechanical milling were reviewed. The Sulfide and oxySulfide Glass–ceramic electrolytes in the system Li 2 S–P 2 S 5 –P 2 O 5 with superionic Li 7 P 3 S 11 and Li 3.25 P 0.95 S 4 crystals exhibited high conductivity of over 10 −3 S cm −1 at room temperature and high electrochemical stability. Newly designed all-Sulfide batteries 80SnS·20P 2 S 5 /80Li 2 S·20P 2 S 5 /75Li 2 S·25Cu were successfully fabricated; reversible charge–discharge capacities of more than 400 mAh g −1 were observed after the second to 10th cycles. The operation of those all-Sulfide lithium secondary batteries is a first step for the realization of the all-solid-state monolithic batteries.
Akitoshi Hayashi - One of the best experts on this subject based on the ideXlab platform.
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evaluation of mechanical properties of na2s p2s5 Sulfide Glass electrolytes
Journal of Materials Chemistry, 2015Co-Authors: Masashi Nose, Akitoshi Hayashi, Atsutaka Kato, Atsushi Sakuda, Masahiro TatsumisagoAbstract:Mechanical properties such as formability and elastic moduli of solid electrolytes are important for the fabrication of all-solid-state batteries and retention of their charge–discharge capacities. In this paper, xNa2S·(100 − x)P2S5 (mol%) Sulfide Glass electrolytes (x = 50, 67, and 75) were prepared and their formability and elastic moduli were evaluated by an ultrasonic pulse-echo technique and a compression test under uniaxial pressing. The Glasses were better densified and showed lower Young's moduli (15–19 GPa) than the Li2S–P2S5 Glasses.
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Sulfide Glass ceramic electrolytes for all solid state lithium and sodium batteries
International Journal of Applied Glass Science, 2014Co-Authors: Masahiro Tatsumisago, Akitoshi HayashiAbstract:Sulfide Glass-ceramic electrolytes with Li+ or Na+ ion conduction have been developed in last decade. High-temperature phases of Li7P3S11 and cubic Na3PS4 are precipitated from mother Glasses, and the obtained Glass-ceramics show higher conductivity than the mother Glasses. It is difficult to synthesize those high-temperature phases by conventional solid-state reaction, and Glass electrolytes are thus important as a precursor for forming high-temperature phases. The highest conductivities at 25°C of 1.1 × 10−2 S/cm for Li+ ion conductor (Li7P3S11) and 7.4 × 10−4 S/cm for Na+ ion conductor (Na3.06P0.94Si0.06S4) are achieved in Sulfide Glass-ceramic electrolytes. All-solid-state batteries with Sulfide Glass-ceramic electrolytes were fabricated by cold press at room temperature. Sulfide electrolytes have favorable mechanical properties to form favorable solid–solid contacts in solid-state batteries by pressing without heat treatment. All-solid-state Li-In/S and Na-Sn/TiS2 cells using Sulfide Glass-ceramic electrolytes operate as secondary batteries and exhibit good cycle performance at room temperature.
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Invited paper: Recent development of bulk-type solid-state rechargeable lithium batteries with Sulfide Glass-ceramic electrolytes
Electronic Materials Letters, 2012Co-Authors: Akitoshi Hayashi, Masahiro TatsumisagoAbstract:The recent development of bulk-type solid-state rechargeable lithium batteries with Sulfide Glass-ceramics as a solid electrolyte was reviewed. Sulfide Glasses and Glass-ceramics in the system Li2S-P2S5 have an advantage of high conductivity, wide electrochemical window and low grain-boundary resistance. Bulk-type solid-state batteries composed of compressed powder layers of electrode and electrolyte were fabricated with Li2S-P2S5 Glass-ceramic electrolytes. Formation of a favorable solid-solid interface between electrode and electrolyte is a key to achieving excellent performance in solid-state batteries. The mechanochemical preparation of nanocomposite electrodes and surface modification of active materials by softening of the electrolyte, or PLD coating, were useful for increasing the electrode-electrolyte contact area and improving battery performance.
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Development of Sulfide Glass-ceramic electrolytes for all-solid-state lithium rechargeable batteries
Journal of Solid State Electrochemistry, 2010Co-Authors: Akitoshi Hayashi, Keiichi Minami, Masahiro TatsumisagoAbstract:Development of Li_2S–P_2S_5-based Glass-ceramic electrolytes is reviewed. Superionic crystals of Li_7P_3S_11 and Li_3.25P_0.95S_4 were precipitated from the Li_2S–P_2S_5 Glasses at the selected compositions. These high temperature or metastable phases enhanced conductivity of Glass ceramics up to over 10^−3 S cm^−1 at room temperature. The original (or mother) Glass electrolytes itself showed somewhat lower conductivity of 10^−4 S cm^−1 and have important role as a precursor for obtaining the superionic crystals, which were not synthesized by a conventional solid-state reaction. The substitution of P_2O_5 for P_2S_5 at the composition 70Li_2S·30P_2S_5 (mol%) improved both conductivity and electrochemical stability of Glass-ceramic electrolytes. The all-solid-state In/LiCoO_2 cell using the 70Li_2S·27P_2S_5·3P_2O_5 (mol%) Glass-ceramic electrolyte showed initial capacity of 105 mAh g^−1 (gram of LiCoO_2) at the current density of 0.13 mA cm^−2 and exhibited higher electrochemical performance than that using the 70Li_2S·30P_2S_5 Glass-ceramic electrolyte.
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high lithium ion conduction of Sulfide Glass based solid electrolytes and their application to all solid state batteries
Journal of Non-crystalline Solids, 2009Co-Authors: Akitoshi Hayashi, Keiichi Minami, Masahiro TatsumisagoAbstract:Abstract Sulfide Glass-based solid electrolytes prepared by melt quenching and mechanical milling were reviewed. The Sulfide and oxySulfide Glass–ceramic electrolytes in the system Li 2 S–P 2 S 5 –P 2 O 5 with superionic Li 7 P 3 S 11 and Li 3.25 P 0.95 S 4 crystals exhibited high conductivity of over 10 −3 S cm −1 at room temperature and high electrochemical stability. Newly designed all-Sulfide batteries 80SnS·20P 2 S 5 /80Li 2 S·20P 2 S 5 /75Li 2 S·25Cu were successfully fabricated; reversible charge–discharge capacities of more than 400 mAh g −1 were observed after the second to 10th cycles. The operation of those all-Sulfide lithium secondary batteries is a first step for the realization of the all-solid-state monolithic batteries.
Ishwar D Aggarwal - One of the best experts on this subject based on the ideXlab platform.
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sputtered films of er3 doped gallium lanthanum Sulfide Glass
Materials Letters, 2006Co-Authors: Jesse A Frantz, Jasbinder S Sanghera, L B Shaw, Guillermo Villalobos, Ishwar D Aggarwal, D W HewakAbstract:Thin films of Er3+-doped gallium lanthanum Sulfide (GLS) Glass were prepared by RF magnetron sputtering onto fused silica and BK7 Glass substrates. The films were characterized by use of SEM imaging, X-ray diffractometry, and energy dispersive spectroscopy. They are shown to be Glassy, uniform in composition, and to exhibit an RMS surface roughness of <8A. The fluorescence lifetimes of the 4I11/2 to 4I13/2 and 4I13/2 to 4I15/2 transitions of Er3+ were measured at each processing stage.
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waveguide amplifiers in sputtered films of er3 doped gallium lanthanum Sulfide Glass
Optics Express, 2006Co-Authors: Jesse A Frantz, Jasbinder S Sanghera, L B Shaw, Ishwar D AggarwalAbstract:Waveguide amplifiers fabricated in Er3+-doped gallium lanthanum Sulfide (GLS) Glass are demonstrated. GLS is deposited onto fused silica substrates by RF magnetron sputtering, and waveguides are patterned by use of the lift-off technique. The waveguides exhibit a total internal gain of 6.7 dB (2.8 dB/cm) for a signal with a wavelength of 1.55μm. This experiment is, to the best of our knowledge, the first demonstration of gain in an Er3+-doped chalcogenide Glass waveguide. The fabrication methods we apply, if used with other rare earth dopants, could potentially be employed to produce sources operating in the mid-IR.
D W Hewak - One of the best experts on this subject based on the ideXlab platform.
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sputtered films of er3 doped gallium lanthanum Sulfide Glass
Materials Letters, 2006Co-Authors: Jesse A Frantz, Jasbinder S Sanghera, L B Shaw, Guillermo Villalobos, Ishwar D Aggarwal, D W HewakAbstract:Thin films of Er3+-doped gallium lanthanum Sulfide (GLS) Glass were prepared by RF magnetron sputtering onto fused silica and BK7 Glass substrates. The films were characterized by use of SEM imaging, X-ray diffractometry, and energy dispersive spectroscopy. They are shown to be Glassy, uniform in composition, and to exhibit an RMS surface roughness of <8A. The fluorescence lifetimes of the 4I11/2 to 4I13/2 and 4I13/2 to 4I15/2 transitions of Er3+ were measured at each processing stage.
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spectroscopic properties and energy transfer parameters of tm3 ions in gallium lanthanum Sulfide Glass
Journal of Physics: Condensed Matter, 2002Co-Authors: A S S De Camargo, S L De Oliveira, D F De Sousa, Luiz Antonio De Oliveira Nunes, D W HewakAbstract:This work presents the spectroscopic characterization of Tm3+ doped gallium lanthanum Sulfide (GaLaS) chalcogenide Glass through absorption, fluorescence and lifetime measurements of excited 3H4 and 3F4 states, and a study of Tm3+:Tm3+ energy transfer. The cross relaxation 3H4,3H6 to 3F4,3F4 responsible for the pumping of level 3F4 and the laser transition at 1800 nm (3F4 to 3H6), as well as the energy migration 3H4,3H6 to 3H4,3H6 processes are studied in terms of the microscopic parameters of energy transfer Cda and Cdd obtained by the Kushida model of multipolar interactions and by a rate equation treatment of the dynamics of levels 3F4 and 3H4. From this treatment it was possible to simulate level 3F4 temporal evolution curves for different Tm3+ concentrations, leading to results that are in excellent agreement with experimental ones. All the samples studied in the work present positive optical gain coefficients for excitation densities higher than 12 kW cm-2 indicating the potentiality of GaLaS:Tm3+ Glass as a mid-infrared laser active medium.
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infrared emission and ion ion interactions in thulium and terbium doped gallium lanthanum Sulfide Glass
Journal of The Optical Society of America B-optical Physics, 1999Co-Authors: T Schweizer, D W Hewak, B N Samson, J R Hector, W S Brocklesby, D N PayneAbstract:Infrared emission at 0.7, 0.8, 1.2, 1.5, 1.8, 2.3, 3.8, and 4.8 µm is measured in thulium- (Tm3+) and terbium- (Tb3+) doped gallium lanthanum Sulfide (GLS) Glass. Emission cross sections are calculated from the absorption and emission spectra by use of Judd–Ofelt analysis, the Fuchtbauer–Ladenburg equation, and the theory of McCumber. Fluorescence and lifetime measurements confirm energy transfer from Tm3+ to Tb3+ ions and reveal a number of new cross-relaxation and upconversion processes between Tm3+ ions involving the 3F2,3 and 3H5 levels that can be observed only in low-phonon-energy materials. These processes indicate that the most efficient pump wavelength for the 1.2- and 3.8-µm transitions is 0.7 µm. The Tm3+ fluorescence at 3.8 µm coincides with an atmospheric transmission window, and the Tb3+ fluorescence at 4.8 µm overlaps the fundamental absorption of carbon monoxide, making the Glass a potential fiber laser source for remote-sensing and gas-sensing applications.
Jesse A Frantz - One of the best experts on this subject based on the ideXlab platform.
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sputtered films of er3 doped gallium lanthanum Sulfide Glass
Materials Letters, 2006Co-Authors: Jesse A Frantz, Jasbinder S Sanghera, L B Shaw, Guillermo Villalobos, Ishwar D Aggarwal, D W HewakAbstract:Thin films of Er3+-doped gallium lanthanum Sulfide (GLS) Glass were prepared by RF magnetron sputtering onto fused silica and BK7 Glass substrates. The films were characterized by use of SEM imaging, X-ray diffractometry, and energy dispersive spectroscopy. They are shown to be Glassy, uniform in composition, and to exhibit an RMS surface roughness of <8A. The fluorescence lifetimes of the 4I11/2 to 4I13/2 and 4I13/2 to 4I15/2 transitions of Er3+ were measured at each processing stage.
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waveguide amplifiers in sputtered films of er3 doped gallium lanthanum Sulfide Glass
Optics Express, 2006Co-Authors: Jesse A Frantz, Jasbinder S Sanghera, L B Shaw, Ishwar D AggarwalAbstract:Waveguide amplifiers fabricated in Er3+-doped gallium lanthanum Sulfide (GLS) Glass are demonstrated. GLS is deposited onto fused silica substrates by RF magnetron sputtering, and waveguides are patterned by use of the lift-off technique. The waveguides exhibit a total internal gain of 6.7 dB (2.8 dB/cm) for a signal with a wavelength of 1.55μm. This experiment is, to the best of our knowledge, the first demonstration of gain in an Er3+-doped chalcogenide Glass waveguide. The fabrication methods we apply, if used with other rare earth dopants, could potentially be employed to produce sources operating in the mid-IR.
