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187 results on '"Ikeda, Naohiro"'

10. Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li₃NbO₄–NiO Binary System

Author

Fukuma, Ryutaro, Harada, Maho, Zhao, Wenwen, Sawamura, Miho, Noda, Yusuke, Nakayama, Masanobu, Goto, Masato, Kan, Daisuke, Shimakawa, Yuichi, Yonemura, Masao, Ikeda, Naohiro, Watanuki, Ryuta, Andersen, Henrik L., D’Angelo, Anita M., Sharma, Neeraj, Park, Jiwon, Byon, Hye Ryung, Fukuyama, Sayuri, Han, Zhenji, Fukumitsu, Hitoshi, Schulz-Dobrick, Martin, Yamanaka, Keisuke, Yamagishi, Hirona, Ohta, Toshiaki, and Yabuuchi, Naoaki

Subjects
Ions, Oxygen, Chemical structure, Transition metals, Redox reactions
Abstract

Dependence on lithium-ion batteries for automobile applications is rapidly increasing. The emerging use of anionic redox can boost the energy density of batteries, but the fundamental origin of anionic redox is still under debate. Moreover, to realize anionic redox, many reported electrode materials rely on manganese ions through π-type interactions with oxygen. Here, through a systematic experimental and theoretical study on a binary system of Li₃NbO₄–NiO, we demonstrate for the first time the unexpectedly large contribution of oxygen to charge compensation for electrochemical oxidation in Ni-based materials. In general, for Ni-based materials, e.g., LiNiO₂, charge compensation is achieved mainly by Ni oxidation, with a lower contribution from oxygen. In contrast, for Li₃NbO₄–NiO, oxygen-based charge compensation is triggered by structural disordering and σ-type interactions with nickel ions, which are associated with a unique environment for oxygen, i.e., a linear Ni–O–Ni configuration in the disordered system. Reversible anionic redox with a small hysteretic behavior was achieved for LiNi₂/₃Nb₁/₃O₂ with a cation-disordered Li/Ni arrangement. Further Li enrichment in the structure destabilizes anionic redox and leads to irreversible oxygen loss due to the disappearance of the linear Ni–O–Ni configuration and the formation of unstable Ni ions with high oxidation states. On the basis of these results, we discuss the possibility of using σ-type interactions for anionic redox to design advanced electrode materials for high-energy lithium-ion batteries., 酸素が反応に寄与するニッケル系電池材料 高エネルギー密度リチウム電池実現に期待 --新規不規則岩塩型ニッケル系材料開発と次世代蓄電池への応用--. 京都大学プレスリリース. 2022-05-24.

Published
2022

16. Progression of glaucomatous optic neuropathy associated with chorioretinal microvascular embolism after intranasal injection of a corticosteroid suspension

Author

Nagasato, Daisuke, Ikeda, Naohiro, Masuda, Akiko, Kashimoto, Ryosuke, and Ikeda, Tomohiro

Subjects
Embolism -- Case studies -- Development and progression -- Care and treatment -- Complications and side effects -- Drug therapy, Retinal diseases -- Case studies -- Development and progression -- Care and treatment -- Complications and side effects -- Drug therapy, Betamethasone -- Case studies -- Complications and side effects, Glaucoma -- Case studies -- Drug therapy, Health
Abstract

Byline: Daisuke. Nagasato, Naohiro. Ikeda, Akiko. Masuda, Ryosuke. Kashimoto, Tomohiro. Ikeda A patient with glaucoma developed sudden blurred vision immediately after the nasal mucosal injection of a betamethasone acetate solution [...]

Published
2020

20. Unexpectedly Large Contribution of Oxygen to Charge Compensation Triggered by Structural Disordering: Detailed Experimental and Theoretical Study on a Li3NbO4–NiO Binary System.

Author

Fukuma, Ryutaro, Harada, Maho, Zhao, Wenwen, Sawamura, Miho, Noda, Yusuke, Nakayama, Masanobu, Goto, Masato, Kan, Daisuke, Shimakawa, Yuichi, Yonemura, Masao, Ikeda, Naohiro, Watanuki, Ryuta, Andersen, Henrik L., D'Angelo, Anita M., Sharma, Neeraj, Park, Jiwon, Byon, Hye Ryung, Fukuyama, Sayuri, Han, Zhenji, and Fukumitsu, Hitoshi

Published
2022
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27. Vision

Author

Ishikawa, Hiroto, primary, Ikeda, Naohiro, additional, Kanno, Sanae, additional, Ikeda, Tomohiro, additional, Mimura, Osamu, additional, and Dezawa, Mari, additional

Published
2010
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31. Evaluation of liver and peripheral blood micronucleus assays with 9 chemicals using young rats: A study by the Collaborative Study Group for the Micronucleus Test (CSGMT)/Japanese Environmental Mutagen Society (JEMS)—Mammalian Mutagenicity Study Group (MMS)

Author

Suzuki, Hiroshi, Ikeda, Naohiro, Kobayashi, Kazuo, Terashima, Yukari, Shimada, Yasushi, Suzuki, Takayoshi, Hagiwara, Toshiyuki, Hatakeyama, Shigeki, Nagaoka, Koko, Yoshida, Junichi, Saito, Yukiko, Tanaka, Jin, and Hayashi, Makoto

Published
2005
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35. Why is the O3 to O1 phase transition hindered in LiNiO2 on full delithiation?

Author

Ikeda, Naohiro, Konuma, Itsuki, Rajendra, Hongahally Basappa, Aida, Taira, and Yabuuchi, Naoaki

Abstract

Ni-enriched layered materials are utilized as positive electrode materials of high-energy Li-ion batteries. Because electrode reversibility is gradually lost for stoichiometric LiNiO2 after continuous cycles, Ni ions are partially substituted by other metal ions (Co, Mn, Al etc.). However, the origin of deterioration in stoichiometric LiNiO2 is still not fully understand yet. Moreover, the loss of capacities is observed only in the high voltage region (>4.1 V), which is obviously different from the failure mode observed in other electrode materials. Here, we report for the first time the origin of deterioration, which is revealed by an in situ X-ray diffraction study. For fully charged NiO2, Ni ions migrate from original octahedral sites in NiO2 slabs to face-sharing tetrahedral sites in Li layers, by which the O3 to O1 phase transition is suppresed. Note that Ni migration is a reversible process, and the Ni ions migrate back to the original octahedral sites on discharge. However, after continuous cycles, the reversibility of Ni migration is gradually lost, and Ni ions are partially left at the tetrahedral sites in Li layers. Electrode kinetics are also deteriorated because of the Ni occupation in Li layers, and the accumulation of Ni ions at tetrahedral sites results in the loss of reversible capacities in the high voltage region. This finding opens a new way to design high-capacity Ni-enriched electrode materials, leading to the development of high-energy Li-ion batteries. [ABSTRACT FROM AUTHOR]

Published
2021
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46. Central venous catheter-related blood stream infection with pyomyositis due toStenotrophomonas maltophiliaafter allogeneic bone marrow transplantation in a patient with aplastic anemia

Author

Kodama, Yuichi, primary, Okamoto, Yasuhiro, additional, Tanabe, Takayuki, additional, Nishikawa, Takuro, additional, Abematsu, Takanari, additional, Nakagawa, Shunsuke, additional, Kurauchi, Koichiro, additional, Shinkoda, Yuichi, additional, Ikeda, Naohiro, additional, Seki, Shunji, additional, Wakiguchi, Hiroyuki, additional, Miyazono, Akinori, additional, and Kawano, Yoshifumi, additional

Published
2016
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49. Detection of Asymptomatic Choroiditis by Fundus Examination in Vogt-Koyanagi-Harada Disease.

Author

Ikeda, Naohiro, Ikeda, Tomohiro, and Iwami, Hisashi

Subjects
*CHOROIDITIS, *FUNDUS oculi, *OPHTHALMOSCOPY, *OPTICAL coherence tomography, *VISUAL acuity
Abstract

Purpose: To describe the ophthalmoscopic changes of the choroidal vessels in the posterior pole of Vogt-Koyanagi-Harada disease patients whose choroid is thickened due to asymptomatic choroiditis.Methods: Three patients whose choroidal vessels are indistinct or not visible in the posterior pole by ophthalmoscopy were examined by fundus photography and enhanced-depth imaging optical coherence tomography (EDI-OCT).Results: They did not complain of vision problems, and visual acuity was good. Serous retinal detachment was not observed by ophthalmoscopy or by OCT. However, choroidal thickening was observed in the EDI-OCT, while choroidal vessels became blurred or invisible on ophthalmoscopy. After steroid therapy, choroidal thickness decreased to normal levels and the small and large choroidal vessels previously indiscernible became visible by ophthalmoscopy and fundus photography.Conclusions: Asymptomatic choroiditis not accompanied by serous retinal detachment can be detected and assessed by observing the changes in the choroidal vessels by ophthalmoscopy and fundus photography. [ABSTRACT FROM AUTHOR]

Published
2017
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