Tomoya Kawaguchi

Materials Scientist

About

photo of me

Hi. I, Tomoya Kawaguchi, Ph.D. is a materials scientist and assistant professor of Institute for Materials Research, Tohoku University in Japan.
See Career for more detail.

My research interests are developing oxide materials for rechargeable batteries such as lithium-ion batteries and magnesium rechargeable batteries based on a concept of nanodomain  microstructure.
See Research for more detail.

Let’s work together.

Research

Develop energy materials

Sustainable society and electric vehicles are facilitated by battery technology; improving battery capacity is one of the social urgent issues today. Transition metal oxide materials are currently used for cathodes of lithium-ion batteries and magnesium rechargeable batteries, facing the intrinsic capacity limit determined by valence change of constituent transition metals. To tackle this problem, I study on strain effect yielded by a nano-domain microstructure in the oxide electrodes, which is expected to unlock large capacity delivered by anionic (e.g., oxygen and sulfur) reduction/oxidation (redox) reaction as well as the conventional cationic reaction.

Unveil subtle difference in “colors” of atoms

“Colors” of an atom in an X-ray region tell us a chemical state of the atom, which is one of the most important clues to understand the origin of materials properties. I have studied on resonant X-ray diffraction spectroscopy, which is a so-called coupling of X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS and also called as XAFS). This technique enables to reveal valence states and local structure of an element at each crystallographic site and phase. I developed a fast measurement technique of diffraction anomalous fine structure (DAFS) and a direct analysis using the logarithmic dispersion relation. This technique was applied to a battery material for the first time, which revealed a degradation mechanism of the first charge/discharge cycle of lithium-ion batteries.

Image material surface and inside

An electrochemical reaction proceeds surface of a material while it also drastically changes inside of the material. Understanding both of them are of great importance to design the material. I developed a direct analysis technique for crystal truncation rod (CTR) analysis, which is so sensitive to the surface that even a single layer change on the surface can be detected. I am also working with Bragg coherent diffraction imaging (BCDI) of an electrode material.

Publication

Journal articles

2021

Accelerated Kinetics Revealing Metastable Pathways of Magnesiation-Induced Transformations in MnO2 Polymorphs

Takuya Hatakeyama, Hongyi Li, Norihiko L. Okamoto, Kohei Shimokawa, Tomoya Kawaguchi, Hiroshi Tanimura, Susumu Imashuku, Maximilian Fichtner, Tetsu Ichitsubo

Accelerated Kinetics Revealing Metastable Pathways of Magnesiation-Induced Transformations in MnO2 Polymorphs Journal Article

Chemistry of Materials, 33 (17), pp. 6983-6996, 2021.

Abstract | Links

Electrochemically Synthesized Liquid-Sulfur/Sulfide Composite Materials for High-rate Magnesium Battery Cathodes

Kohei Shimokawa, Takuya Furuhashi, Tomoya Kawaguchi, Won-Young Park, Takeshi Wada, Hajime Matsumoto, Hidemi Katoa, Tetsu Ichitsubo

Electrochemically Synthesized Liquid-Sulfur/Sulfide Composite Materials for High-rate Magnesium Battery Cathodes Journal Article

Journal of Materials Chemistry A, 9 , pp. 16585-16593, 2021.

Abstract | Links

Electrochemically Induced Strain Evolution in Pt-Ni Alloy Nanoparticles Observed by Bragg Coherent Diffraction Imaging

Tomoya Kawaguchi, Vladimir Komanicky, Vitalii Latyshev, Wonsuk Cha, Evan Maxey, Ross Harder, Tetsu Ichitsubo, Hoydoo You

Electrochemically Induced Strain Evolution in Pt-Ni Alloy Nanoparticles Observed by Bragg Coherent Diffraction Imaging Journal Article

Nano Letters, 21 (14), pp. 5945–5951, 2021.

Abstract | Links

(Review) Relaxation Behavior an Heterogeneous Structure of Metallic Glasses

Hiroshi Tanimura, Tomoki Hayashi, Martin Luckabauer, Tomoya Kawaguchi, Masato Wakeda, Hidemi Kato, Tetsu Ichitsubo

(Review) Relaxation Behavior an Heterogeneous Structure of Metallic Glasses Journal Article

Journal of the Society of Materials, Japan, 70 (5), pp. 374-380, 2021.

Links

pH- and Cation-Dependent Water Oxidation on Rutile RuO2(110)

Reshma R. Rao, Botao Huang, Yu Katayama, Jonathan Hwang, Tomoya Kawaguchi, Jaclyn R. Lunger, Jiayu Peng, Yirui Zhang, Asuka Morinaga, Hua Zhou, Hoydoo You, Yang Shao-Horn

pH- and Cation-Dependent Water Oxidation on Rutile RuO2(110) Journal Article

The Journal of Physical Chemistry C, 125 (15), pp. 8195-8207, 2021.

Abstract | Links

Structure Design of Long-Life Spinel-Oxide Cathode Materials for Magnesium Rechargeable Batteries

Kohei Shimokawa, Taruto Atsumi, Norihiko L. Okamoto, Tomoya Kawaguchi, Susumu Imashuku, Kazuaki Wagatsuma, Masanobu Nakayama, Kiyoshi Kanamura, Tetsu Ichitsubo

Structure Design of Long-Life Spinel-Oxide Cathode Materials for Magnesium Rechargeable Batteries Journal Article

Advanced Materials, 33 (7), pp. 2007539, 2021.

Abstract | Links

2020

In Situ Strain Evolution on Pt Nanoparticles during Hydrogen Peroxide Decomposition

Sungwook Choi, Myungwoo Chung, Dongjin Kim, Sungwon Kim, Kyuseok Yun, Wonsuk Cha, Ross Harder, Tomoya Kawaguchi, Yihua Liu, Andrew Ulvestad, Hoydoo You, Mee Kyung Song, and Hyunjung Kim

In Situ Strain Evolution on Pt Nanoparticles during Hydrogen Peroxide Decomposition Journal Article

Nano Letters, 20 (12), pp. 8541–8548, 2020.

Abstract | Links

Disordered Cubic Spinel Structure in the Delithiated Li2MnO3 Revealed by Difference Pair Distribution Function Analysis

Masatsugu Oishi, Keiji Shimoda, Koji Ohara, Daiki Kabutan, Tomoya Kawaguchi, Yoshiharu Uchimoto

Disordered Cubic Spinel Structure in the Delithiated Li2MnO3 Revealed by Difference Pair Distribution Function Analysis Journal Article

Journal of Physical Chemistry C, 124 , pp. 24081−24089, 2020.

Abstract | Links

In-situ to ex-situ in-plane structure evolution of stern layers on Pt(111) surface: Surface X-ray scattering studies

Tomoya Kawaguchi, Yihua Liua, Evguenia A.Karapetrova, Vladimir Komanicky, Hoydoo You

In-situ to ex-situ in-plane structure evolution of stern layers on Pt(111) surface: Surface X-ray scattering studies Journal Article

Journal of Electroanalytical Chemistry, 875 (15), pp. 114495, 2020.

Abstract | Links

Stern layers on RuO2 (100) and (110) in electrolyte: Surface X-ray scattering studies

Tomoya Kawaguchi, Reshma R. Rao, Jaclyn R. Lunger, Yihua Liu, Donald Walko, Evguenia A. Karapetrova, Vladimir Komanicky, Yang Shao-Horn, Hoydoo You

Stern layers on RuO2 (100) and (110) in electrolyte: Surface X-ray scattering studies Journal Article

Journal of Electroanalytical Chemistry, 875 (15), pp. 114228, 2020.

Abstract | Links

Development of a half-cell for X-ray structural analysis of liquid electrolytes in rechargeable batteries

Koji Kimura, Hisao Kiuchi, Masahito Morita, Tomoya Kawaguchi, Kazuki Yoshii, Hikari Sakaebe, Kouichi Hayashi

Development of a half-cell for X-ray structural analysis of liquid electrolytes in rechargeable batteries Journal Article

Review of Scientific Instruments, 91 , pp. 033907, 2020.

Abstract | Links

Dynamic stability of active sites in hydr(oxy)oxides for the oxygen evolution reaction

Dong Young Chung, Pietro P. Lopes, Pedro Farinazzo Bergamo Dias Martins, Haiying He, Tomoya Kawaguchi, Peter Zapol, Hoydoo You, Dusan Tripkovic, Dusan Strmcnik, Yisi Zhu, Soenke Seifert, Sungsik Lee, Vojislav R. Stamenkovic, Nenad M. Markovic

Dynamic stability of active sites in hydr(oxy)oxides for the oxygen evolution reaction Journal Article

Nature Energy, 5 , pp. 222-230, 2020.

Abstract | Links

Direct observation of elastic softening immediately after femtosecond-laser excitation in a phase-change material

Tomoya Kawaguchi, Kazuya Tokuda, Seiya Okada, Makina Yabashi, Tetsu Ichitsubo, Noboru Yamada, Eiichiro Matsubara

Direct observation of elastic softening immediately after femtosecond-laser excitation in a phase-change material Journal Article

Physical Review B Rapid Communication, 101 , pp. 060302(R), 2020.

Abstract | Links

2019

Gas-induced segregation in Pt-Rh alloy nanoparticles observed by in situ Bragg coherent diffraction imaging

Tomoya Kawaguchi, Thomas F. Keller, Henning Runge, Luca Gelisio, Christoph Seitz, Young Y. Kim, Evan R. Maxey, Wonsuk Cha, Andrew Ulvestad, Stephan O. Hruszkewycz, Ross Harder, Ivan A. Vartanyants, Andreas Stierle, Hoydoo You

Gas-induced segregation in Pt-Rh alloy nanoparticles observed by in situ Bragg coherent diffraction imaging Journal Article

Physical Review Letters, 123 , pp. 246001, 2019.

Abstract | Links

Study of the Internal Compositions of Binary Alloy Pd-Rh Nanoparticles by Using Bragg Coherent Diffraction Imaging

Tomoya Kawaguchi, Wonsuk Cha, Vitalii Latyshev, Serhii Vorobiov, Vladimir Komanicky, Hoydoo You

Study of the Internal Compositions of Binary Alloy Pd-Rh Nanoparticles by Using Bragg Coherent Diffraction Imaging Journal Article

Journal of the Korean Physical Society, 75 (7), pp. 528-533, 2019.

Abstract | Links

High Anionic Conductive Form of PbxSn2–xF4

Miwa Murakami, Yoshiyuki Morita, Masao Yonemura, Keiji Shimoda, Masahiro Mori, Yukinori Koyama, Tomoya Kawaguchi, Katsutoshi Fukuda, Yoshihisa Ishikawa, Takashi Kamiyama, Yoshiharu Uchimoto, Zempachi Ogumi

High Anionic Conductive Form of PbxSn2–xF4 Journal Article

Chemistry of Materials, 31 (18), pp. 7704-7710, 2019.

Abstract | Links

Anomalous Antiferromagnetism in Metallic RuO2 Determined by Resonant X-ray Scattering

Zhihai H. Zhu, Joerg Strempfer, Reshma R. Rao, Connor A. Occhialini, Jonathan Pelliciari, Yongseong Choi, Tomoya Kawaguchi, Hoydoo You, John F. Mitchell, Yang Shao-Horn, and Riccardo Comin

Anomalous Antiferromagnetism in Metallic RuO2 Determined by Resonant X-ray Scattering Journal Article

Phycal Review Letters, 122 , pp. 017202, 2019.

Abstract | Links

Electrochemical phase transformation accompanied with Mg extraction and insertion in a spinel MgMn2O4 cathode material

Takuya Hatakeyama, Norihiko L Okamoto, Kohei Shimokawa, Hongyi Li, Aiko Nakao, Yoshiharu Uchimoto, Hiroshi Tanimura, Tomoya Kawaguchi, Tetsu Ichitsubo

Electrochemical phase transformation accompanied with Mg extraction and insertion in a spinel MgMn2O4 cathode material Journal Article

Phys. Chem. Chem. Phys., 21 , pp. 23749-23757, 2019.

Abstract | Links

Continue reading “Publication”

News&Articles

Complex Refractive Index

Generally, optics based on the electromagnetics is described with the refractive index, while such index does not barely appear in X-ray diffraction (XRD) from the kinematical approach, presumably because of the different historical background; however, it is of great importance to see their relationship to understand the diffraction anomalous fine structure (DAFS) method.
Read More…

Resonant Scattering

The atomic form factor is a Fourier transform of the electron distribution in an atom; therefore, it is a real number and independent of photon energy. In contrast, there exists an absorption edge and a fine structure in an absorption spectrum in the x-ray region. Thus, the absorption term should be included into the scattering length as an imaginary part, which is proportional to the absorption cross-section, by assuming a more elaborated model rather than that of a cloud of free electrons.
Read More…

Calculation of a structure factor

A structure factor is calculated by summing up scattering factors of each atom with multiplying the phases at each atomic position in a unit cell. It is a facile approach to calculate the structure factor; however, the calculation becomes complicated when the unit cell includes the large number of atoms. Thus, the calculation of the structure factor should be carried out based on the crystallographic site in space group, which is more versatile and convenient.
Read More…

Career

Assistant professor
Institute for Materials Research, Tohoku University, Japan,  2018-
Structure-Controlled Functional Materials Laboratory (prof. Tetsu Ichitsubo)

Previously..

Resident associate
Materials Science Division, Argonne National Laboratory, U.S.A., 2017-2019
Synchrotron Studies of Materials Group (supervisor: Hoydoo You)

JSPS overseas research fellow
Japan Society for Promotion of Science (JSPS), Japan, 2017-2019

Research assistant professor
Technical Director (Synchrotron Radiation Study Group) of RISING and RISING2 projects

Office of Society Academia Collaboration for Innovation, Kyoto University, Japan, 2015-2017

JSPS research fellow (DC2), JSPS, Japan, 2013 – 2015

Background

Education

  • Ph.D., Materials Science, Kyoto University, Kyoto, Japan, 2015
  • M.S., Material Science, Kyoto University, Kyoto, Japan, 2012
  • B.S., Engineering Science, Kyoto University, Kyoto, Japan, 2010
  • Science and Mathematics Course, Otemae High School, Osaka, Japan, 2006
  • TOEIC score: 925/990 as of 2019

Awards and Honors

  • Encouraging award, the Japanese Society for Synchrotron Radiation Research (JSSRR), 2016
  • Best student presentation award, annual meeting of JSSRR, 2015
  • Best student presentation award, annual meeting of JSSRR, 2014
  • Best student presentation award, annual meeting of JSSRR, 2013
  • (more…)

Research Experience

Argonne National Laboratory

Structural analysis of the electrochemical double layer using crystal truncation rod (CTR) analysis. Direct determination of the surface structure from CTR. Bragg coherent diffraction imaging of the internal composition of the alloy catalysis particles, Materials Science Division, Argonne National Laboratory, 2017 – 2019

(more…)