A5024318252- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Advanced Battery Technologies Research
- Thermal Expansion and Ionic Conductivity
- Supercapacitor Materials and Fabrication
- Electron and X-Ray Spectroscopy Techniques
- Ferroelectric and Piezoelectric Materials
- X-ray Diffraction in Crystallography
- Extraction and Separation Processes
- Crystallization and Solubility Studies
- Vibration and Dynamic Analysis
- Advanced battery technologies research
- Transition Metal Oxide Nanomaterials
- Thermal Analysis in Power Transmission
- Semiconductor materials and devices
- Microwave Dielectric Ceramics Synthesis
- Solid-state spectroscopy and crystallography
- Chemical Synthesis and Characterization
- Zeolite Catalysis and Synthesis
- X-ray Spectroscopy and Fluorescence Analysis
- Icing and De-icing Technologies
- Catalytic Processes in Materials Science
- Conducting polymers and applications
- Semiconductor materials and interfaces
- Advancements in Solid Oxide Fuel Cells
National Institute of Advanced Industrial Science and Technology
2016-2025
Midorigaoka Hospital
2018-2020
Mie University
2017
Central Research Institute of Electric Power Industry
2017
Nagoya University
2017
Ikeda Municipal Hospital
2016
Ubiquitous Energy (United States)
2014
Kyoto University
1985-2011
Shibaura Institute of Technology
2011
Semiconductor Energy Laboratory (Japan)
2009
Abstract Rechargeable potassium-ion batteries have been gaining traction as not only promising low-cost alternatives to lithium-ion technology, but also high-voltage energy storage systems. However, their development and sustainability are plagued by the lack of suitable electrode materials capable allowing reversible insertion large potassium ions. Here, exploration database for potassium-based has led us discover ion conducting layered honeycomb frameworks. They show capability ions at...
A unique charge/discharge mechanism of amorphous TiS4 is reported. Amorphous transition metal polysulfide electrodes exhibit anomalous performance and should have a mechanism: neither the typical intercalation/deintercalation nor conversion-type one, but mixture two. Analyzing such has been challenge because fewer tools are available to examine "amorphous" structure. It revealed that electrode undergoes two distinct structural changes: (i) deformation formation S–S disulfide bonds (ii)...
Depth-resolved X-ray absorption spectroscopy (DR-XAS) measurements were performed for the direct observation of chemical state and local structure at LiCoO2 electrode–solid electrolyte model interface, which can contribute towards enhancement power density in all solid-state lithium batteries. The charge transfer resistance, measured by AC impedance spectroscopy, interface decreased with introduction a NbO2 interlayer while resistance increased ZrO2 MoO2 interlayers. Using DR-XAS depth...
The use of oxide electrolytes promises the safety Li-ion batteries but complicates fabrication electrochemical interfaces. Herein, we report facile preparation ionic-transferable interfaces between electrode and electrolyte in oxide-based bulk-type all-solid-state lithium-ion (ASS-LIBs) owing to deformability LISICON–Li3BO3 amorphous oxide, which cannot be realized with currently popular crystalline electrolytes. was used assemble an ASS-LIB even without firing. Moreover, low-temperature...
Designing composite electrodes with optimal microstructure, composition, and choice of active material (AM) as well solid electrolyte (SE) is critically important for the development high-performance solid-state batteries (SSBs). To optimize AM loading, which includes loading amount, dispersion state, to maximize utilization in SSB electrodes, we need precisely understand how affects electrochemical reactions taking place electrodes. Here, using computed tomography combined X-ray absorption...
The performances of electrochemical systems such as solid-state batteries (SSBs) can be severely hindered by the three-dimensional (3D) and mesoscopically inhomogeneous reactions that take place in electrodes. However, majority existing methods for analyzing are restricted to one- or two-dimensional observations. Herein, we performed 3D operando imaging reaction a composite SSB electrode using hard X-ray computed-tomography with absorption near edge structure spectroscopy (CT-XANES)....
In light emitting diodes, Y3Al5O12:Ce (YAG:Ce) is used as a yellow phosphor in combination with blue LEDs but lacks red component emission. Therefore, considerable efforts have been directed toward shifting the emission of YAG:Ce to longer wavelengths. this study, Y3Al5O12 (YAG) crystal incorporating high content Ce, (Y1-x Ce x )3Al5O12 (0.006 ≦ 0.21), was successfully prepared by polymerized complex method which low-temperature annealing (650-750 °C) employed prior sintering at 1080 °C....
Complex compositional control is typically required in developing ionic conductors to tune their lattice size and the number of carriers. Moreover, complexity may affect ion-conducting properties. Therefore, this study, lithium superionic (LISICONs) with γ-Li3PO4-type structures were developed quasi-ternary (Li-M-M′-M″-O) systems elucidate multicomponent effects. Among compounds examined, Li3.68(Ge0.6V0.36Ga0.04)O4 Li4GeO4–Li3VO4–Li5GaO4 ternary system exhibited highest conductivity (1.5 ×...
Abstract Investigating local strain distributions is essential for developing long‐life all‐solid‐state batteries (ASSBs) because capacity fading primarily results from cracks and contact loss caused by volume changes in electrode active materials during battery operation. Digital image correlation (DIC) analysis can be used to create distribution maps continuous images of under applied pressure. In this study, DIC operando confocal microscopy an ASSB cross‐section was conducted elucidate...
X-Ray absorption fine structure (XAFS) spectroscopy was carried out on submicron sized TiO2-B, which is one of the promising candidates for negative electrode materials, in order to clarify electronic and local structural changes during its lithium-ion insertion process. From extended X-ray (EXAFS) results lithiated LixTiO2-B, we propose sites electrochemical discharging. The lithium ions are inserted into five-fold coordinated and/or distorted octahedral distributed at vicinity O layers...
Specific charge–discharge properties of Li<sub>5</sub>FeO<sub>4</sub>positive electrodes with regard to bulk and surface structural changes during the first charging process analyzed by synchrotron techniques including XRD, XANES, EXAFS.
The sulfide solid electrolyte Li4SnS4 has gained attention owing to its high moisture durability.In this study, we quantitatively investigated the changes in electrochemical properties and chemical/physical states of resulted from exposure using XRD, Raman spectroscopy, high-frequency impedance spectroscopy (HF-EIS).Li4SnS4 was subjected Ar gas flow at a dew point ranging -20 °C 0 for 1 h, hydrolysis generated only minute amount H2S.The XRD patterns spectra revealed formation Li4SnS4•4H2O...
First-principle calculation was employed to simulate X-ray absorption near-edge structure (XANES) spectroscopy of two typical types lithium cobalt oxides clarify the electronic and local structural changes during lithium-ion de-intercalation. The simulated Co K-edge XANES spectra agreed well with observed spectra. differences in shape symmetry and/or contents were analyzed based on partial density state (PDOS) excited energy level. simulations revealed that PDOS overlapped nearby via oxygen...
Garnet-type Li7La3Zr2O12 (LLZ) has advantages of stability with Li metal and high Li+ ionic conductivity, achieving 1 × 10–3 S cm–1, but it is prone to react electrode active materials during the sintering process. LISICON-type Li3.5Ge0.5V0.5O4 (LGVO) advantage less reactivity material process, its conductivity on order 10–5 cm–1. In this study, these two solid electrolytes are combined as a multilayer electrolyte sheet, where 2 μm thick LGVO films coated LLZ sheets utilize electrolytes....
Conversion-type iron trifluoride (FeF3) has attracted considerable attention as a positive electrode material for lithium secondary batteries due to its high energy density and low cost. However, the conversion process through which FeF3 operates leads it suffer from capacity degradation upon repeated cycling. To improve cycle performance, in this study we investigated mechanism of conversion-type material. Bulk analyses cycling reveal incomplete oxidation Fe3+ concomitant with aggregation...
A technique of two‐wavelength holographic interferometry was applied to simultaneously measure the concentration profiles Cu2+ ion and H+ near a plane vertical cathode placed in an unstirred aqueous solution containing excess . It revealed that measured are approximated with parabolic equations horizontal distance from surface gradient at is larger than same cathodic current density distance. The following matters were also clarified: (i) nondimensional rate ionic mass transfer shown as...
TiO2–B nanowires were prepared by hydrothermal reaction, and the nanosized effect on lithium-ion insertion was investigated using X-ray absorption spectroscopy (XAS). On basis of results O K-edge near-edge structure (XANES) with various particle sizes, it suggested that surface has local electronic structures being different from bulk, band energy lower than bulk. The vended structure, which is called space charge layer (SCL), makes in smooth because SCL maintained during insertion, shown Ti...
In order to investigate lithium ion conduction mechanism of the ion–conducting perovskite oxides, La2/3−xLi3xTiO3 (x = 0.06–0.15) (LLT), their average structure, local structure and conductivity were analyzed. We applied Rietveld analysis with X-ray diffraction for discussing LLT disordered (high temperature phase, HT) ordered (low LT) A-site arrangements along c-axis its orthorhombic lattice. Synchrotron absorption fine (XAFS) was also measured considering structures. Differences migration...
DFT calculation reveals that local structural characteristics in lithium manganese spinel oxides such as ion displacement change due to phase transition can be detected from XANES spectra.