A5047904426- Advancements in Battery Materials
- Advanced Battery Materials and Technologies
- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- Advancements in Solid Oxide Fuel Cells
- Advanced Battery Technologies Research
- Magnetic and transport properties of perovskites and related materials
- Semiconductor materials and devices
- Thermal Expansion and Ionic Conductivity
- Advanced Condensed Matter Physics
- Nuclear materials and radiation effects
- Electron and X-Ray Spectroscopy Techniques
- Advanced Thermoelectric Materials and Devices
- Multiferroics and related materials
- Advanced ceramic materials synthesis
- Microwave Dielectric Ceramics Synthesis
- Extraction and Separation Processes
- Solid-state spectroscopy and crystallography
- High-Temperature Coating Behaviors
- Transition Metal Oxide Nanomaterials
- Gas Sensing Nanomaterials and Sensors
- Catalytic Processes in Materials Science
- Semiconductor materials and interfaces
- Acoustic Wave Resonator Technologies
- ZnO doping and properties
Takeda (United States)
2023-2024
Japan Fine Ceramics Center
2014-2023
Tokyo Institute of Technology
2016-2023
Kumamoto University
2023
Tokyo University of Science
2023
National Institute for Materials Science
2020
Kyushu University
2020
National Institute of Advanced Industrial Science and Technology
2020
National Defense Academy of Japan
2020
Shanxi University
2016
Key issues relating to intrinsic defects, dopant incorporation, and lithium ion migration in the LiFePO4 electrode material have been investigated using well-established atomistic modeling techniques. Our simulation model shows good reproduction of observed olivine-type structure LiFePO4. The most favorable defect is Li−Fe "anti-site" pair which a Li (on M1 site) an Fe M2 are interchanged. This type anti-site or "intersite exchange" has olivine silicates. lowest energy found for pathway...
The defect chemistry, doping behavior, and ion migration in olivine-type materials LiMPO4 (M = Mn, Fe, Co, N) are investigated by atomistic simulation techniques. most favorable intrinsic type is found to be the cation antisite defect, which Li M ions exchange positions. occur preferentially down [010] channels, following a curved trajectory. Defect association or binding energies for pair clusters composed of combinations lithium vacancies, cations, small polaron species investigated....
Electron holography reveals how lithium ions are distributed during the charge/discharge cycle of a battery. A steep potential drop and gradually extended slope (ca. 1.5 μm) due to electrical double layer formed near electrode/electrolyte interface, where resistance ion transfer occurs.
In this article, we try to answer the fundamental question in Na-ion batteries using DFT calculations: why is sodium-intercalated graphite unstable?
A method for efficiently screening a wide compositional and structural phase space of LISICON-type superionic conductors is presented that utilizes machine-learning technique combining theoretical experimental datasets. By iteratively performing systematic sets first-principles calculations focused experiments, it shown how the materials design process can be greatly accelerated, suggesting potentially superior candidate lithium conductors.
Advanced simulation techniques are used to provide atomic-scale insight into the surface structures and crystal morphologies of lithium battery cathode material LiFePO4. Relaxed energies reported for 19 low index planes. The calculated equilibrium morphology takes on a rounded, isometric appearance, with {010}, {201}, {011}, {100} faces prominent. Almost all energy surfaces lithium-deficient relative bulk lattice, requiring Li vacancies at surface. growth exhibits {101} faces, an elongated...
Results of theoretical calculations are reported, examining the effect a coherent twin boundary on electrical properties LiCoO(2) . This study suggests that internal interfaces in strongly affect battery voltage, capacity, and power density this material, which is particular concern if it used all-solid-state Li-ion batteries.
The microstructure of LiNi 0.8 Co 0.15 Al 0.05 O 2 positive electrode material before and after the first cycle was investigated by scanning transmission electron microscopy (STEM) energy loss spectroscopy (EELS). STEM EELS analysis shows that, cycling, there are very thin layers at grain boundaries that contain a small amount transition metal ions (particularly Ni) on Li sites. After cycle, thickness some boundary increases significantly, accompanied formation microcracks boundaries. Also,...
Direct observation of light elements (Li and O) in oxygen-deficient lithium manganese spinel by spherical aberration-corrected scanning transmission electron microscopy is reported. A previously unknown ordered structure was revealed annular dark-field (ADF) imaging oxygen columns, while Li ions are visualized successfully bright-field (ABF) (see picture).
The search for new low-cost and safe cathodes next-generation lithium batteries has led to increasing interest in silicate materials. Here, a systematic comparison of crystal properties, defect chemistry Li-ion migration behaviour four polymorphs Li2MnSiO4 is reported based on the results atomistic simulations. examined have Pmn21, Pmnb, P21/n, Pn symmetry. Lattice energies all are very similar, with only small energy preference two orthorhombic phases over monoclinic phases, which explains...
Lanthanum lithium titanate (LLTO) is one of the most promising electrolyte materials for all-solid-state lithium-ion batteries. Despite numerous studies, detailed crystal structure still open to conjecture because difficulty identifying precisely positions Li atoms and distribution intrinsic cation vacancies. Here we use subangstrom resolution scanning transmission electron microscopy (STEM) imaging methods spatially resolved energy loss spectroscopy (EELS) analysis examine local atomic...
We have developed Tersoff potential parameters for boron in order to simulate cubic carbonitride systems by molecular dynamics. Combined with C and N available from the literature, our are shown reproduce lattice bulk moduli of nitride (C 0.33 (BN) 0.67 ) good accuracy. By simulating several formula x 1- over a wide range carbon contents ( =0 1), we observed same trends deviation ideal mixing as found experimentally. attribute this relatively longer C-N bonds distributed randomly throughout...
Atomic-resolution STEM and EELS analysis provide insights into microscopic mechanisms behind oxygen loss capacity fade in spinel-structured lithium-ion battery cathode material LiMn<sub>2</sub>O<sub>4</sub>.
The possibility of the new class ferroelectric materials wurtzite structure simple chalcogenide was discussed using modern first-principles calculation technique. Ferroelectricity in (P63mc) can be understood by distortion from centrosymmetric P63/mmc relative displacement cation against anion along c-axis. Calculated potential surface these compounds shows typical double well between two polar variants. barriers for polarization switching were estimated to 0.25 eV/f.u. ZnO. It is slightly...
Perovskite-type lanthanum lithium titanate (LLTO) is attracting extensive interest because of its high intrinsic ionic conductivity. The material exhibits a complex microstructure with domains various sizes and orientations that vary the content. Based on systematic examination both Li-poor Li-rich LLTO compounds using state-of-the-art scanning transmission electron microscopy (STEM), we reveal structures composition domain boundaries (DBs) consider their effect Li-ion mobility conductivity,...
Abstract Quantifying the dependence of thermal conductivity on grain boundary (GB) structure is critical for controlling nanoscale transport in many technologically important materials. A major obstacle to determining such a relationship lack robust and physically intuitive descriptor capable distinguishing between disparate GB structures. We demonstrate that microscopic metric, local distortion factor, correlates well with atomically decomposed conductivities obtained from perturbed...