A5035293042- Graphene research and applications
- Advancements in Battery Materials
- Electrochemical Analysis and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Battery Materials and Technologies
- Electrocatalysts for Energy Conversion
- Advanced Battery Technologies Research
- Supercapacitor Materials and Fabrication
- Machine Learning in Materials Science
- Quantum and electron transport phenomena
- Fullerene Chemistry and Applications
- Carbon Nanotubes in Composites
- Surface and Thin Film Phenomena
- Molecular Junctions and Nanostructures
- MXene and MAX Phase Materials
- Fuel Cells and Related Materials
- Surface Roughness and Optical Measurements
- Advanced Memory and Neural Computing
- Optical Coatings and Gratings
- Semiconductor materials and devices
- Boron and Carbon Nanomaterials Research
- 2D Materials and Applications
- High-pressure geophysics and materials
- Electrostatics and Colloid Interactions
- Advancements in Photolithography Techniques
University of Tsukuba
2002-2024
Hyogo University
2023-2024
Kyoto University
2013-2022
National Institute of Advanced Industrial Science and Technology
2013-2022
The University of Tokyo
2001-2021
University of Pittsburgh
2020
Dassault Systèmes (Germany)
2020
National Institute of Standards and Technology
2020
Rensselaer Polytechnic Institute
2020
NTL Institute for Applied Behavioral Science
2020
A new first-principles computational approach to a charged surface/interface is presented. The surface modeled as slab imposed with boundary conditions screen the excess charge. To treat this model, which nonperiodic in normal direction, standard pseudopotential plane-wave scheme modified at Poisson solver part help of Green's function technique. Benchmark calculations are done for $\mathrm{Al}∕\mathrm{Si}(111)$ bias voltage applied between and model scanning tunneling microscopy (STM) tip,...
Abstract In spite of recent progress, there is still a lack reliable organic electrodes for Li storage with high comprehensive performance, especially in terms long‐term cycling stability. Herein, we report an ideal polymer electrode based on anthraquinone, namely, polyanthraquinone (PAQ), or specifically, poly(1,4‐anthraquinone) (P14AQ) and poly(1,5‐anthraquinone) (P15AQ). As lithium‐storage cathode, P14AQ showed exceptional including reversible capacity almost equal to the theoretical...
We present a comparative van der Waals density-functional (vdW-DF) study of graphene adsorbed on (111) surfaces Ni, Cu, Pd, Ag, Au, and Pt, using the second version vdW-DF (vdW-DF2) Lee et al. [Phys. Rev. B 82, 081101(R) (2010)] exchange functional (C09) developed by Cooper 81, 161104(R) (2010)]. show that use vdW-DF2 correlation together with C09 yields most satisfactory results: Adsorption geometries are in good agreement available experiment data, electronic structure varies depending...
In concern of resource sustainability and environmental friendliness, organic electrode materials for rechargeable batteries have attracted increasing attentions in recent years. However, many researchers, the primary impression on cathode is poor cycling stability low energy density, mainly due to unfavorable dissolution redox potential, respectively. Herein, a novel polymer material, namely poly(benzoquinonyl sulfide) (PBQS) reported, either Li or Na battery. Remarkably, PBQS shows high...
Organic electrode materials are promising alternatives to transition-metal based intercalation compounds for the next generation of high-performance and sustainable batteries. Herein, a novel quinone-based organic, lithium salt poly(2,5-dihydroxy-p-benzoquinonyl sulfide) (Li2PDHBQS), was successfully synthesized through simple one-step polycondensation reaction, applied as cathode Li–organic As an oligomeric with average polymerization degree 7, Li2PDHBQS combines advantages O⋯Li⋯O...
Mix transition metal layered oxide materials are much attractive for cathode in lithium ion batteries. However, the disordered arrangement between and ions local regions of these always occurs, seriously affects their electrochemical performance. Here we report experimental first-principles calculations Li+/Ni2+ exchange LiNi0.42Mn0.42Co0.16O2 prepared by solid state reaction co-precipitation methods. The impact on crystal/electronic structure, performance stress investigated detail. results...
Abstract Electric double-layer capacitors are efficient energy storage devices that have the potential to account for uneven power demand in sustainable systems. Earlier attempts improve an unsatisfactory capacitance of electric focused on meso- or nanostructuring increase accessible surface area and minimize distance between adsorbed ions electrode. However, dielectric constant electrolyte solvent embedded electrode surface, which also governs capacitance, has not been previously exploited...
A simulation scheme for performing first-principles molecular dynamics at a constant electrode potential is presented, opening the way more realistic modeling of voltage-driven devices. The system allowed to exchange electrons with reservoir fixed potential, and dynamical equations total electronic charge are derived by using energy extended system. In combination thermostat, this potentiostat reproduces thermal fluctuations correct statistics, implying treatment as control variable....
First-principles total energy calculations are performed to investigate the energetics and electronic structures of graphene adsorbed on both an oxygen-terminated SiO2 (0001) surface a fully hydroxylated surface. We find that there several stable adsorption sites for O-terminated surfaces. The binding in most geometry is found be 15 meV per C atom, indicating weak interaction between also semiconductor irrespective arrangement due variation on-site induced by substrate.
We present two hybrid solvation models for the calculation of structure with model 1 in a confined nanospace bulk materials and 2 at solid/liquid interfaces where an electrode is contact electrolyte membrane immersed into solution. The theory based on reference interaction site method (RISM) solvent region. electronic material, electrode, treated by density functional plane-wave basis pseudopotentials technique. For 1, we use three-dimensional RISM (3D-RISM) imposing 3D periodic boundary...
Using density-functional theory calculations on a variety of model surfaces, we demonstrate that the low theoretical quantum capacitance graphene-based electrodes can be significantly improved by altering local structural and morphological features. Common point defects, dopants, strain, surface rippling are considered, as well differences between locally single-layer multilayer configurations. Local curvature is particularly effective at improving capacitance, inclusion certain defects...
The investigation of electrode dynamics has been a major topic in the field electrochemistry for century. Electrode consist electron transfer reactions that give rise to, or are caused by, bias voltage, and influenced by surface catalysis, electrolyte solution, transport electrons ions. first-principles molecular simulation electrochemical system hampered difficulty to describe voltage complex solution-electrode interface structure. Here we utilize new algorithm called effective screening...
Abstract MXene electrodes in electrochemical capacitors have a distinctive behavior that is both capacitive and pseudocapacitive depending on the electrolyte. In this work, to better understand their mechanism, first‐principles calculations based density functional theory combined with implicit solvation model are used (termed as 3D reference‐interaction‐site model). From viewpoint of electronic states, hydration shell prevents orbital coupling between intercalated ions, which leads...
Abstract In spite of recent progress, there is still a lack reliable organic electrodes for Li storage with high comprehensive performance, especially in terms long‐term cycling stability. Herein, we report an ideal polymer electrode based on anthraquinone, namely, polyanthraquinone (PAQ), or specifically, poly(1,4‐anthraquinone) (P14AQ) and poly(1,5‐anthraquinone) (P15AQ). As lithium‐storage cathode, P14AQ showed exceptional including reversible capacity almost equal to the theoretical...
We present a method that makes it possible to determine an electrode potential in electrode/electrolyte solution system. consider the of standard hydrogen (SHE) reaction...
Abstract Improved understanding of aqueous solutions at graphitic interfaces is critical for energy storage and water desalination. However, many mechanistic details remain unclear, including how interfacial structure response are dictated by intrinsic properties solvated ions under applied voltage. In this work, we combine hybrid first-principles/continuum simulations with electrochemical measurements to investigate adsorption several alkali-metal cations the interface graphene within...
Engineering the electrolyte microenvironment represents an attractive route to tuning selectivity of electrocatalytic reactions beyond catalyst composition and morphology. However, harnessing full potential this approach requires understanding interplay between voltage, composition, adsorbate binding within electrical double layer, which is absent from usual theoretical approaches. In work, we apply a recently developed density functional theory (DFT)-continuum based on effective screening...
Abstract The interplay among magnetism, electronic nematicity, and superconductivity is the key issue in strongly correlated materials including iron-based, cuprate, heavy-fermion superconductors. Magnetic fluctuations have been widely discussed as a pairing mechanism of unconventional superconductivity, but recent theory predicts that quantum nematic order may also promote high-temperature superconductivity. This has studied FeSe 1− x S superconductors exhibiting nonmagnetic...
MXenes are emerging electrode materials intended for electric double-layer capacitors because of their large specific capacitance more than 300 F/g. Recent advances in synthesis methods have enabled a decrease surface functional groups and chemical control design, but the influence on capacitive properties is still unclear. Here, we applied density theory combined with effective screening medium reference interaction site model calculations to systematically investigate atomic-scale...
Ab initio molecular dynamics simulations have been performed on the water/Pt interface. When surface is neutral, water found to form a contact layer directing its O atom toward surface, i.e., O-down configuration. negatively biased, shows significant structural change. The configuration converted mostly H-down As biased more strongly, we find that hydrophobic double formed in layer.
Electron transport in bilayer graphene placed under a perpendicular electric field is revealed experimentally. Steep increase of the resistance observed high field; however, does not diverge even at low temperatures. The temperature dependence conductance consists two contributions: thermally activated (TA) conduction and variable range hopping (VRH) conduction. We find that for measured (0-1.3 V/nm) mobility gap extracted from TA behavior agrees well with theoretical prediction band opening...
Similar to Li–S batteries, Li–organic batteries have also been plagued by the dissolution of active materials and resulting shuttle effect for many years. An effective strategy eliminate is adopting solid electrolytes or Li–ion permselective separators prohibit dissolved electroactive species from migrating Li anode. A polypropylene/Nafion/polypropylene (PNP) sandwich‐type separator reported with advantages in comparison previously LISICON, polymer electrolyte, other Nafion utilization...
The current energy crisis and environmental problems associated with the use of fossil fuels necessitate a transition to clean sustainable carriers like hydrogen produced by electrocatalytic water splitting. Hence, development robust, low-cost, high-performance oxygen evolution reaction (OER) electrocatalysts has attracted considerable attention. Herein, an OER electrocatalyst for in alkaline media is prepared hybridising rhombohedral boron monosulfide graphene provide electronic...
We report total-energy electronic-structure calculations that provide energetics and electronic structures of fullerenes encapsulated in zigzag carbon nanotubes (so-called peapods). It is found the space between nanotube a decisive factor to determine for encapsulation process stability resultant structures. The reaction energies processes exhibit common characteristics depending on inside tube, irrespective their metallic semiconducting properties. also peapods depend they reflect electron...