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Chief Scientist Laboratories Solid State Chemistry Laboratory

Chief Scientist: Genki Kobayashi (Ph.D.)

Research Summary


Effective utilization of renewable energy and a shift away from mass consumption of fossil fuels are essential for building a sustainable society, which requires new technologies that enable highly efficient energy and material conversion and high-density energy storage. Based on inorganic solid-state chemistry, we explore outstanding ionics materials, including electrodes and solid electrolytes with innovative functions. We are researching a wide range of topics, from elucidating the mechanisms of physical properties and functions to developing energy storage/conversion and material conversion devices based on new operating principles.

Main Research Fields

  • Chemistry

Related Research Fields

  • Engineering
  • Interdisciplinary Science & Engineering
  • Inorganic Materials Chemistry
  • Energy-related Chemistry
  • Inorganic Materials and properties


  • Solid State Ionics
  • Exploration for New Functional Materials
  • Energy Storage & Conversion
  • Material Conversion
  • Ceramics

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

  • 1. *Takeiri, F., Watanabe, A., Okamoto, K., Bresser, D., Lyonnard, S., Frick, B., Ali, A., Imai, Y., Nishimura, M., Yonemura, M., Saito, T., Ikeda, K., Otomo, T., Kamiyama, T., Kanno, R., Kobayashi, G.:
    "Hydride-Ion-Conducting K2NiF4-Type Ba-Li Oxyhydride Solid Electrolyte"
    Nature Materials 21, 325-330 (2022).
  • 2. *Morgan, H., Yamamoto, T., Nishikubo, T., Ohmi, T., Koike, T., Sakai, Y., Azuma, M., Ishii, H., Kobayashi, G., McGrady, J.:
    "Sequential Pressure-Induced B1-B2 Transitions in the Anion-Ordered Oxyhydride Ba2YHO3"
    Inorg. Chem. 61, 7043-7050 (2022).
  • 3. *Uchimura, T., Takeiri, F., Okamoto, K., Saito, T., Kamiyama, T., Kobayashi, G.:
    "Direct Synthesis of Barium Titanium Oxyhydride for Use as a Hydrogen Permeable Electrode"
    J. Materials Chem. A 9, 20371-20374 (2021).
  • 4. *Matsui, N., Hinuma, Y., Iwasaki, Y., Suzuki, K., Guangzhoung, J., Nawaz H., Imai, Y., Yonemura, M., Hirayama, M., Kobayashi, G., Kanno, R.:
    "The Effect of Cation Size on Hydride-Ion Conduction in LnSrLiH2O2 (Ln = La, Pr, Nd, Sm, Gd) Oxyhydrides"
    J. Mater Chem. A 8, 24685-24694 (2020).
  • 5. *Nawaz, H., Takeiri, F., Kuwabara, A., Yonemura, M., Kobayashi, G.:
    "Synthesis and H Conductivity of New Oxyhydride Ba2YHO3 with Anion-Ordered Rock-Salt Layers"
    Chem. Commun. 56, 10373-10376 (2020).
  • 6. *Takeiri, F., Watanabe, A., Kuwabara, A., Nawaz, H., Ayu, N., Yonemura, M., Kanno, R., Kobayashi, G.:
    "Ba2ScHO3: H Conductive Layered Oxhydride with H Site Selectivity"
    Inorg. Chem. 58, 4431-4436 (2019).
  • 7. *Matsui, N., Kobayashi, G., Suzuki, K., Watanabe, A., Kubota, A., Iwasaki, Y., Yonemura, M., Hirayama, M., Kanno, R.:
    "Ambient Pressure Synthesis of La2LiHO3 as a Solid Electrolyte for a Hydrogen Electrochemical Cell"
    J. Am. Ceram. Soc. 102, 3228-3235 (2019).
  • 8. *Watanabe, A., Kobayashi, G., Matsui, N., Yonemura, M., Kubota, A., Suzuki, K., Hirayama, M., Kanno, R.:
    "Ambient Pressure Synthesis and H Conductivity of LaSrLiH2O2"
    Electrochem. 85(2), 88-92 (2017).
  • 9. *Kobayashi, G., Hinumra, Y., Matsuoka, S., Watanabe, A., Iqbal, M., Hirayama, M., Yonemura, M., Kamiyama, T., Kanno, R.:
    "Pure H Conduction in Oxyhydrides"
    Science 351, 1314-1317 (2016).
  • 10. *Kobayashi, G., Irii, Y., Matsumoto, F., Ito, A., Ohsawa, Y., Yamamoto, S., Cui, Y., Son, J.-Y., Sato, Y.:
    "Improving Cycling Performance of Li-Rich Layered Cathode Materials Through Combination of Al2O3-Based Surface Modification and Stepwise Pre-cycling"
    J. Power Sources 303, 250-256 (2016).

Lab Members

Principal investigator

Genki Kobayashi
Chief Scientist

Contact Information

N505 Chemistry and Materials Physics Building
2-1 Hirosawa, Wako, Saitama 351-0198, Japan
Email: genki.kobayashi [at] riken.jp