Taketoshi Minato

Institute for Molecular Science

We investigated the reaction mechanism of the desorption of single hydrogen from a titanium dioxide surface excited by the tip of a scanning tunneling microscope (STM). Analysis of the desorption yield, in combination with theoretical calculations, indicates the crucial role played by the applied electric field. Instead of facilitating desorption b...

The application potential of Li-ion batteries is growing as demand increases in different fields at various stages in energy systems, in addition to their conventional role as power sources for portable devices. In particular, applications in electric vehicles and renewable energy storage are increasing for Li-ion batteries. For these applications,...

Viscosity of the solvation structures is crucial for the development of energy-efficient biochemical and electrochemical devices. Elucidating their subnanoscale distributions can cause the formation of a sustainable energy society. Here, we visualize the three-dimensional damping distribution on a CaCO3 surface composing binary ion species using ul...

我々の住むこの世界は原子分子から構成され，運動（移動），熱，光，電気，反応等のエネルギーが生み出されている．これらのエネルギーを理解し，制御していくことは，我々の生活を便利にするだけでなく，深みや豊かさを与えてくれる．2011 年3 月11 日に我々 が経験した東日本大震災は，そのエネルギーに関する技術のあるべき姿を再考するきっかけとなり，現在，エネルギーの理解と制御に関わる研究は最も注目されるトピックスの一つとなっている．多くのエネルギー技術の中で二次電池を用いてエネルギーを蓄積し，利 用する時，場所，そして量を制御する技術は，多様性を有する社会を築く基盤となり得ることから，その持続的な発展が強く望まれている．二次電池の中で，リチウムイオン二次電池は現在最も広く利用されている．これまでリチ...

Understanding and controlling the mechanism of energy conversion related to the development of a sustainable society not only make our lives more convenient but also make them more meaningful and enrichens us. The physical properties at the interface between solid and liquid (solid/liquid interface) play a significant role in energy conversion. The...

Despite the rapid progresses in the field of organic semiconductors, aided by the development of high-mobility organic materials, their high carrier mobilities are often unipolar, being sufficiently high only for either electrons or holes. Yet, the basic mechanisms underlying such significant mobility asymmetry largely remains elusive. We perform a...

This study investigates the interface between ice and organic solvents using atomic force microscopy (AFM). Atomically flat ice surfaces were prepared and observed by AFM in 1-octanol, 1-hexanol, and 1-butanol. The results show differences in surface roughness influenced by the interaction of ice and alcohols. Young’s modulus of ice was analyzed by...

Recent advancements in computational science and interfacial measurements have sparked interest in microscopic water droplets and their diverse behaviors. A previous study using nonlinear spectroscopy revealed the heterogeneous wetting phenomenon of silica glass in response to humidity. Building on this premise, we employed high-resolution atomic f...

The functionalities of materials are governed by the atom type and arrangement, and perturbations caused by defects and adsorbate interactions often significantly alter the behavior of materials. Scanning probe microscopy (SPM) can capture complex interactions caused by the structures on surfaces. It is, however, difficult to analyze such interacti...

This study particularly compares the surface tensions and contact angles for molten bis(fluorosulfonyl)amide salts of imidazolium, ammonium, and phosphonium cations with the pentyl, ethoxyethyl, or ethylthioethyl group. The examined substrate plates for contact angle measurements include silicate glass, platinum, copper, graphene, and polytetrafluo...

Enantioselectivity of helical aggregation is conventionally directed either by its homochiral ingredients or by introduction of chiral catalysis. The fundamental question, then, is whether helical aggregation that consists only of achiral components can obtain enantioselectivity in the absence of chiral catalysis. Here, by exploiting enantiospecifi...

Chiral molecules have recently received renewed interest as highly efficient sources of spin‐selective charge emission known as chiral‐induced spin selectivity (CISS), which potentially offers a fascinating utilization of organic chiral materials in novel solid‐state spintronic devices. However, a practical use of CISS remains far from completion,...

Fluoride shuttle batteries (FSBs) are promising next‐generation rechargeable batteries. To analyze the detailed local environment in the electrolytes of FSBs, the dynamics of the molecules and ions in an electrolyte, prepared using 2, 4, 6‐trimethoxyboroxine (TMBX)—a liquid‐type anion acceptor, were investigated using nuclear magnetic resonance. Th...

Fluoride shuttle batteries (FSBs) are superior to lithium-ion batteries (LIBs) in terms of high energy density, safety, etc. An electrolyte consisting of tetraglyme (G4) as a solvent molecule and triphenylboroxine (TPhBX) as an anion acceptor to improve the solubility of cesium fluoride (CsF) salt is a candidate of the electrolytes for FSBs. The lo...

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to “the Project”) in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented...

Fluoride shuttle batteries (FSBs), which utilize F– ion migration in electrochemical reactions, have recently advanced in academic research as next-generation rechargeable batteries. Bismuth trifluoride (BiF3) and its relatives are expected to be promising positive electrode materials for FSBs because of their high theoretical capacity. Herein, the...

Rechargeable secondary batteries operating through fluoride-ion shuttling between the positive and negative electrodes, referred to as fluoride shuttle batteries (FSBs), offer a potentially promising solution to overcoming the energy-density limitations of current lithium-ion battery systems. However, there are many technical issues that need to be...

Understanding the subnanoscale solvation structures of ionic liquids is crucial for the development of innovative functional 'devices' across numerous fields. We previously demonstrated the atomic-scale solvation measurements using an ultra-low noise 3D frequency-modulation atomic force microscopy combined with molecular dynamics simulations. Howev...

The potential effects of using lithium bis(oxalato)borate (LiBOB) as an electrolyte additive on the redox reactions of the positive bismuth fluoride (BiF3) electrode were investigated in tetraglyme (G4) containing the anion acceptor (AA) triphenylboroxin (TPhBX). The electrolyte system, containing 0.06 M LiBOB, 0.5 M TPhBX, and saturated cesium flu...

X‐ray total scattering was applied to a series of molecular liquids, including the CsF salt, which is expected to be a promising electrolyte in fluoride shuttle batteries. These electrolytes are composed of solvent molecules and addition agent (AAs), together with CsF. We used tetraglyme (G4) or γ‐butyloractone (GBL) as a solvent molecule, and lith...

An electrolyte for fluoride shuttle battery was composed of bis[2-(2-methoxyethoxy)ethyl]ether, a cesium fluoride, and an anion acceptor (AA; triphenylborane, fluorobis(2,4,6-trimethylphenyl)borane, or triphenylboroxine). The battery performance of bismuth(III) fluoride in the electrolytes with fluorobis(2,4,6-trimethylphenyl)borane and triphenylbo...

We previously developed a fluoride shuttle battery containing a bismuth(III) fluoride (BiF3) electrode; however, the battery exhibited several drawbacks including poor cycling performance and low practical capacity. In this research, to obtain a BiF3 electrode with high cycling performance and practical capacity, an electrolyte containing triphenyl...

The fluoride shuttle batteries (FSBs) represent one of the potentially promising beyond-lithium-ion innovative battery systems, operating with a redox-active fluoride-ion transporting electrolyte. The low-weight, anion-based, multi-electron-transfer reactions at the anode and cathode, with a wide range of options on metals and their fluoride counte...

Solid solution of bismuth(III) fluoride (BiF3) and barium(II) fluoride (BaF2) with a variety of crystal structures was prepared, and their electrochemical performances were evaluated on a fluoride shuttle battery (FSB) system. BiF3‐BaF2 based solid solution (Bi1‐xBaxF3‐x (x=0) with orthorhombic phase, x=0.2 with hexagonal phase, and x=0.4 with cubi...

The electrochemical reaction in a fluoride shuttle battery (FSB) requires an organic solvent containing a supporting electrolyte salt. To dissolve an insoluble inorganic fluoride compound (e.g., cesium fluoride (CsF)) in an organic solvent (e.g., bis[2-(2-methoxyethoxy)ethyl]ether [tetraglyme, G4]), an anion acceptor (AA) (e.g., triphenylborane (TP...

Weight densities obtained by MD simulations, observation mechanism of force profile, consideration of solvation structure on SiO2/Si tip, dependence on ionic concentration (simulations), weight densities of EAN solutions, weight densities of emim-DCA solutions, imaging force dependence of topography, concentration dependence of experimental solvati...

3D force maps of EAN and emim-DCA

MD simulation results

https://www.shokubai.org/jnl/pageview?articlecd=62010004000 Titanium dioxide is a typical transition metal oxide used as catalytic materials. The functionality of titanium dioxide is strongly influenced by defects. To understand the physical nature of the defects, I have been used scanning probe microscopy. In this paper, the summary of my investi...

Room-temperature ionic liquids are useful media for future-generation electrochemical, catalytic, and biological devices due to their various superior characteristics. Since the device performance is often dictated by the solvation structures at solid–liquid interfaces, their atomistic pictures are in great demand. However, there have been no exper...

国家／プラトン著／ 本書で行われている議論の中には、現代の倫理観では受け入れ難い部分も多い。学生の頃にこの本を読んだ私は、その後の哲学に多大な影響を与えたとされるこの本が書かれた時代で、何故このような倫理観が受け入れられたか考えた。そして、その後人類は歴史を経て、当時とは異なる倫理観にどのようにして達したのだろうかと考えた。さらに、この本の中で行われている正義に関する議論の姿勢から、私自身が目指していた研究者にとって、どのように行動していくことが正義となるのかを考え、研究者としての自分の行為の価値基準をどこに置くかということを考える上で大きな参考になった。科学の評価の仕方も時代を経て変化するが、持続的に人々にいいsignalを与える成果を得るためにどうすればいいかを、今でも常に考えている。

Fluoride ion shuttle batteries (FSBs), alternatively referred to as fluoride ion batteries (FIBs), are anion-based rechargeable batteries with fluoride (F ⁻ ) ions as charge transporting and redox active species, and potentially offer a high electrochemical energy storage capability that overwhelms those of the state-of-the-art lithium ion batterie...

二次電池は、近年の環境、エネルギー問題改善に重要な役割を果たすキーデバイスである。我々は、新しい原理に基づき、既存の二次電池の性能を超える理論性能を保有する「フッ化物イオンシャトル二次電池」の開発に取り組み、有機電解液を用いた可逆な脱フッ化、フッ化反応を世界で初めて達成した。さらに、電解液や電極の制御による電極反応の改善、および新規な電極材料、電解液の開発に成功した。これらの成果は、電気自動車や再生可能エネルギーの貯蔵などに用いる二次電池の工業化を目指した研究に進展している。以下に詳細を記載する。

Correction for ‘Effects of LiBOB on salt solubility and BiF 3 electrode electrochemical properties in fluoride shuttle batteries’ by Asuman Celik Kucuk et al. , J. Mater. Chem. A , 2019, 7 , 8559–8567.

Lead fluoride (PbF2) is a promising electrode material for fluoride shuttle batteries (FSBs) owing to its high theoretical capacity (219 mAh g–1). In this study, the discharge and charge capacities of a PbF2 electrode were measured using a bis[2‐(2‐methoxyethoxy)ethyl] ether containing cesium fluoride and triphenylborane as an electrolyte. A high s...

Fluoride shuttle battery (FSB) is a promising next-generation battery candidate. In the FSB, metal fluoride and organic solvent containing supporting electrolyte salt and anion acceptor were used as active material and electrolyte. In this study, using bis[2-(2-methoxyethoxy)ethyl] ether (tetraglyme: G4) containing cesium fluoride (CsF; 0.45 mol dm...

In fluoride shuttle batteries (FSBs), the addition of an anion acceptor (AA) is required to dissolve the supporting electrolyte salt in an organic solvent. Based on theoretical calculations and practical experiments, the effectiveness of triphenylboroxine (TPhBX) as an AA for FSB was verified. Using an electrolyte with TPhBX as an AA, the specific...

Bismuth fluoride (BiF3) is a promising positive electrode material for fluoride shuttle batteries (FSBs) owing to its high theoretical specific capacity (302 mA h g−1). However, it exhibits low practical capacity. The methods for preparing the electrode are known to have significant effects on battery performance. The mixture between BiF3 and carbo...

In this study, lithium bis(oxalato)borate (LiBOB) was used for the first time in a fluoride shuttle battery (FSB) to overcome the solubility problem of fluorine-based salts typically present in organic solvents. For this purpose, tetraglyme (G4) electrolytes containing CsF salt and LiBOB with three different concentrations (LiBOB 0.06 /CsF/G4, LiBO...

We have developed a fluoride shuttle battery (FSB) which is a promising candidate for the next-generation high-energy-density secondary batteries. Using the bis [2-(2-methoxyethoxy) ethyl] ether (tetraglyme: G4) solvent containing 0.45 mol dm⁻³ cesium fluoride (CsF) and 0.5 mol dm⁻³ fluorobis (2,4,6-trimethylphenyl) borane (FBTMPhB) as an electroly...

For liquid-based fluoride shuttle batteries, electrolyte composed of organic solvent and supporting electrolyte salt is developed. To increase the solubility of supporting electrolyte salt in organic solvent, anion acceptors (triphenylboroxine or triphenylborane) are added. The addition of anion acceptor greatly increases the solubility of supporti...

Li-rich type manganese oxides are one of the most promising cathodes for lithium-ion batteries in recent years; thanks to their high energy density. In these cathodes, partial substitution of manganese by other transition metals such as nickel and cobalt has been proposed and shown to be effective in improving the performance; however, the role of...

Recently, the reversible discharge and charge reaction of BiF3 electrode for fluoride shuttle battery (FSB) that can be used as a promising candidate for next-generation battery are observed using a liquid-based electrolyte. In this study, we investigate the electrochemical performance of PbF2 as an active material for the FSB. To increase the elec...

Hydration structures at solid–liquid interfaces mediate between the atomic-level surface structures and macroscopic functionalities in various physical, chemical, and biological processes. Atomic-scale local hydration measurements have been enabled by ultra-low noise 3D frequency-modulation atomic force microscopy. However, for their application to...

In a lithium ion battery, lithiation and delithiation of active materials occur during charging and discharging, and diffusion of Li (or Li vacancy) and related phase transformation in the active material greatly affect battery performance. Evolution and migration of Li-deficient phases at surfaces of single crystals of LiFePO4 (2×3×6 mm in size) d...

To expand the applications of secondary batteries, we have developed a new reserve-type fluoride shuttle battery (FSB) as a promising next-generation secondary battery candidate. For a FSB, a metal fluoride and an organic solvent are applied as the active material and electrolyte, respectively, and the dissolution and deposition of the active mater...

The conversion-based BiF3 is a promising cathode material for lithium-ion batteries due to its high theoretical capacity (302 mAh g⁻¹). Nanocomposites of BiF3 and carbon (BiF3/C) are known to improve the electrochemical performance by increasing the electronic conductivity of the electrode. Here we investigate the electrochemical performance of BiF...

リチウムイオン電池に代表される蓄電池の内部において、電極と電解質の界面（電極／電解質界面）の物性や、そこで起きる化学反応は、電池の性能に大きな影響を与えることが知られている。しかし、その詳細は不明なことが多く、性能改善の妨げとなってきた。湊丈俊氏は表面・界面を解析する技術を駆使することで、電極／電解質界面の物性や化学反応機構を解明し、これまで不明であった新しい蓄電池の設計指針を構築した。これらの成果は蓄電池の発展に寄与すると期待される。

Clarification of the details of the interface structure between liquids and solids is crucial for understanding the fundamental processes of physical functions. Herein, we investigate the structure of the interface between tetraglyme and graphite and propose a model for the interface structure based on the observation of frequency-modulation atomic...

The electrochemical reaction mechanism for Bi1-xBaxF3-x (x=0, 0.1, 0.2, and 0.4) electrode materials, which have several crystal structures, was investigated. As the barium content x increased, the crystal structure changed from orthorhombic (x=0) to hexagonal (x=0.1 and 0.2) and cubic (x=0.4). For x=0.1 and 0.2, the discharge voltage and capacity...

The nanocomposite of BiF3 and carbon (BiF3/C) is a promising cathode material for lithium-ion batteries because of its high capacity. When BiF3/C was charged and discharged within voltage range of 2.0–4.5 V, the BiF3/C exhibited high capacity; however, as the cycle progressed, the discharge-charge capacities decreased and the charge voltage shifted...

Clarification of the interaction between the electrode and the electrolyte is crucial for further improvement of the performance of lithium-ion batteries. We have investigated the structural change at the interface between the surface of a 104-oriented epitaxial thin film of LiCoO2 (LiCoO2(104)), which is one of the stable surfaces of LiCoO2, and a...

LiCoO 2 electrode exhibits severe capacity fading when charged to 4.4 V, although it delivers a higher capacity of over 150 mAh g ⁻¹ at the initial cycles [1]. Surface coating with metal oxides and phosphates has been one of the effective methods to improve cycle performance [1,2]. The coating layer with very small thickness of ca. 0.5−1 nm improve...

1. Introduction Li-rich type (manganese) oxides are one of the most featured cathodes for lithium ion batteries in recent years, owing to their high capacity and cyclability. In these cathodes, partial substitution of manganese by other transition metals such as Ni and Co has been proposed and shown to be effective in improving the performance, [1]...

For the first time H-H dissociation on unsupported nanoporous gold (AuNPore) surface for chemoselective hydrogenation of C≡C, C=C, C=N, C=O bonds under mild conditions (8 atm H2 pressure, 90 oC) is reported. The silver doping in AuNPore, which was inevitable for its preparation through dealloying process of Au-Ag alloy, exhibited a remarkable diffe...

Li2MnO3, an electrode material for Li ion batteries, belongs to the C2/m space group and is known to have a cubic-close-packed (ABC...) layered structure, in which the transition-metal layer is supposed to have an ordered atomic arrangement with Li atoms at the 2b site and Mn atoms at the 4g site. However, recently, it has been reported that this c...

We examined the crystal structures of Li2(NixMn1-x)O3(-δ) (x = 0, 1/10, 1/6, and 1/4) to elucidate the relationship between the structure and electrochemical performance of the compounds using neutron and synchrotron X-ray powder diffraction analyses in combination. Our examination revealed that these crystals contain a large number of stacking fau...

The oxidation/reduction behaviours of lattice oxygen and transition metals in a Li-rich manganese-based layered oxide Li[Li0.25Ni0.20Mn0.55]O1.93 are investigated by using hard X-ray photoelectron spectroscopy (HAX-PES). By making use of its deeper probing depth rather than in-house XPS analyses, we clearly confirm the formation of O− ions as bulk...

The lifetime of a lithium-ion battery is often affected by deterioration of the positive electrode. It is well known that the deterioration of the positive electrode can be reduced by electrolyte additives; however, the mechanism underlying this improvement needs to be clarified. In this study, we investigate the electronic structure at the electro...

Degradation mechanism of surface coating effects at the cathode/electrolyte interface is investigated using thin-film model electrodes combined with operando X-ray absorption spectroscopy (XAS). MgO-coated LiCoO2 thin-film electrodes prepared via pulsed laser deposition at room temperature and high temperature are used as model systems. The MgO coa...

The functionality of solid materials is defined by the type and ordering of the constituent atoms. By introducing defects that perturb the ordered structure, new functionality is created within the solid material. Atomic defects in titanium dioxide, such as oxygen vacancies, atomic hydrogen, and interstitial Ti, typically create new functionality....

A stoichiometric MgFePO4F (MFPF) is synthesised by using a solid-state carbothermal method. Its monoclinic framework, possessing an entire cationic mixing of Mg2+ and Fe2+, is validated via both crystal structure analysis and simulation. Interestingly, MFPF exhibits a relatively high potential ([similar]2.6 V vs. Mg/Mg2+) and good cyclic stability...

Surface coating on lithium-ion battery cathodes improves their durability at high potentials, which is a well-known practical application. However, the mechanism is still unclear because the coating influences the electrode/electrolyte interface at a few nanometer-scale and direct observation of the interface under real operating conditions of a ba...

Rechargeable magnesium batteries are poised to be viable candidates for large-scale energy storage devices in smart grid communities and electric vehicles. However, the energy density of previously proposed rechargeable magnesium batteries is low, limited mainly by the cathode materials. Here, we present new design approaches for the cathode in ord...

Several research groups have reported that the cathode/electrolyte interface plays an essential role for the deterioration of lithium ion batteries [1, 2]. To further enhance the cycle time of lithium-ion batteries, it is important to understand the reactions at the cathode/electrolyte interface. However, the mechanisms of such interface reactions...

1. Introduction Magnesium rechargeable batteries are considered as viable alternatives for next generation large-scale energy storage devices. Magnesium provides two electrons per atom (divalent nature of Mg ²⁺ ), making it an attractive high-energy density battery system over the existing lithium-ion technology. ¹ However, the specific energy dens...

Magnesium rechargeable batteries have paid attention for the next generation battery, because magnesium metal has a higher volumetric specific capacity and higher melting point than these of lithium metal. Electrolyte for magnesium rechargeable batteries has been developed by Aurbach and co-workers [1, 2], in which Grignard reagents (RMgX, where R...