Updated on 2022/05/22

写真a

 
KAWAI, Kosuke
 
Affiliation
Faculty of Science and Engineering, Waseda Research Institute for Science and Engineering
Job title
Junior Researcher(Assistant Professor)
Mail Address
メールアドレス

Education

  • 2018.04
    -
    2021.03

    The University of Tokyo   The Graduate School of Engineering   Department of Chemical System Engineering  

  • 2016.04
    -
    2018.03

    The University of Tokyo   The Graduate School of Engineering   Department of Chemical System Engineering  

  • 2012.04
    -
    2016.03

    Kyoto University   Faculty of Engineering   School of Industrial Chemistry  

Degree

  • 2021.03   The University of Tokyo   Doctor

  • 2018.03   The University of Tokyo   Master

  • 2016.03   Kyoto University   Bachelor

Research Experience

  • 2021.07
    -
    Now

    Waseda University   Research Institute for Science and Engineering   Junior researcher

  • 2021.04
    -
    2021.06

    Waseda University   School of Advanced Science and Engineering   JSPS Research Fellowships for Young Scientists PD

  • 2020.04
    -
    2021.03

    The University of Tokyo   The Graduate School of Engineering   JSPS Research Fellowships for Young Scientists PD

  • 2016.10
    -
    2021.03

    The University of Tokyo

Professional Memberships

  • 2019.01
    -
    Now

    公益社団法人 電気化学会

 

Research Areas

  • Inorganic materials and properties   蓄電材料

Papers

  • Kinetic square scheme in oxygen-redox battery electrodes

    Kosuke Kawai, Xiang-Mei Shi, Norio Takenaka, Jeonguk Jang, Benoit Mortemard de Boisse, Akihisa Tsuchimoto, Daisuke Asakura, Jun Kikkawa, Masanobu Nakayama, Masashi Okubo, Atsuo Yamada

    Energy & Environmental Science    2022.05  [Refereed]

    Authorship:Lead author

    DOI

  • Lithium-Rich O2-Type Li0.66[Li0.22Ru0.78]O2 Positive Electrode Material

    Hirohito Umeno, Kosuke Kawai, Shin-ichi Nishimura, Daisuke Asakura, Masashi Okubo, Atsuo Yamada

    Journal of The Electrochemical Society   169 ( 4 ) 040536 - 040536  2022.04  [Refereed]

     View Summary

    Increasing the energy density of lithium-ion batteries is an important step towards flexible electricity supply, which can be achieved by developing large-capacity positive electrodes. Lithium-rich oxides have been a longstanding research target because of their large capacity involving extra oxygen-redox reactions. In this work, we report the synthesis, electrochemical properties, electronic structure, and structural evolution of O2-type lithium-rich layered oxide Li1.22‒xRu0.78O2. A robust Ru‒O layered framework without Ru migration allows for unveiling the solid-state electrochemistry of O2-type lithium-rich layered oxides with possibility of a large yet stable extra capacity for oxygen-redox reaction. Using a combination of X-ray photoelectron spectroscopy, X-ray absorption/emission spectroscopy, and in situ/ex situ X-ray diffraction, we clarified that O2-Li1.22‒xRu0.78O2 delivers a large capacity of 200 mAh g‒1 in association with Ru5+/Ru4+ and Ru4+/Ru3+ two-electron redox reactions under a solid-solution process, but with no contribution from the extra oxygen-redox reaction.

    DOI

  • Oxygen redox versus oxygen evolution in aqueous electrolytes: critical influence of transition metals

    Hirohito Umeno, Kosuke Kawai, Daisuke Asakura, Masashi Okubo, Atsuo Yamada

    Advanced Science     2104907  2022.02  [Refereed]

  • Square-Scheme Electrochemistry in Battery Electrodes

    Masashi Okubo, Kosuke Kawai, Zihan Ma, Atsuo Yamada

    Accounts of Materials Research   3 ( 1 ) 33 - 41  2021.11  [Refereed]  [Invited]

  • 4.7 V Operation of the Cr4+/Cr3+ Redox Couple in Na3Cr2(PO4)2F3

    Kosuke Kawai, Daisuke Asakura, Shin-ichi Nishimura, Atsuo Yamada

    Chemistry of Materials   33 ( 4 ) 1373 - 1379  2021.02  [Refereed]

    Authorship:Lead author

    DOI

  • Nonpolarizing oxygen-redox capacity without O-O dimerization in Na2Mn3O7

    Akihisa Tsuchimoto, Xiang-Mei Shi, Kosuke Kawai, Benoit Mortemard de Boisse, Jun Kikkawa, Daisuke Asakura, Masashi Okubo, Atsuo Yamada

    Nature Communications   12 ( 1 ) 631  2021.01  [Refereed]

     View Summary

    <title>Abstract</title>Reversibility of an electrode reaction is important for energy-efficient rechargeable batteries with a long battery life. Additional oxygen-redox reactions have become an intensive area of research to achieve a larger specific capacity of the positive electrode materials. However, most oxygen-redox electrodes exhibit a large voltage hysteresis &gt;0.5 V upon charge/discharge, and hence possess unacceptably poor energy efficiency. The hysteresis is thought to originate from the formation of peroxide-like O22− dimers during the oxygen-redox reaction. Therefore, avoiding O-O dimer formation is an essential challenge to overcome. Here, we focus on Na2-<italic>x</italic>Mn3O7, which we recently identified to exhibit a large reversible oxygen-redox capacity with an extremely small polarization of 0.04 V. Using spectroscopic and magnetic measurements, the existence of stable O−• was identified in Na2-<italic>x</italic>Mn3O7. Computations reveal that O−• is thermodynamically favorable over the peroxide-like O22− dimer as a result of hole stabilization through a (σ + π) multiorbital Mn-O bond.

    DOI

  • Stabilization of a 4.5 V Cr4+/Cr3+ redox reaction in NASICON-type Na3Cr2(PO4)3 by Ti substitution

    Kosuke Kawai, Daisuke Asakura, Shin-ichi Nishimura, Atsuo Yamada

    Chemical Communications   55 ( 91 ) 13717 - 13720  2019.09  [Refereed]

    Authorship:Lead author

     View Summary

    <p>NASICON-type Na2CrTi(PO4)3 offers a stable redox reaction of Cr4+/Cr3+ at 4.5 V <italic>vs.</italic> Na/Na+.</p>

    DOI

  • High-Voltage Cr4+/Cr3+ Redox Couple in Polyanion Compounds

    Kosuke Kawai, Wenwen Zhao, Shin-ichi Nishimura, Atsuo Yamada

    ACS Applied Energy Materials   1 ( 3 ) 928 - 931  2018.02  [Refereed]

    Authorship:Lead author

    DOI

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Awards

  • 電気化学会第87回大会優秀学生発表賞

    2020.03   公益社団法人 電気化学会