HOME > Profile > KUWATA, Naoaki
- Principal Researcher, Battery Interface Control Group, Battery and Cell Materials Field, Research Center for Energy and Environmental Materials (GREEN)
- All Solid State Team, Center for Advanced Battery Collaboration, Research Center for Energy and Environmental Materials (GREEN)
- Battery Research Platform, Research Center for Energy and Environmental Materials (GREEN)
- MOP Assistant Platform Director, Materials Open Platform for All Solid-State Battery, External Collaboration Division
- Address
- 305-0044 1-1 Namiki Tsukuba Ibaraki JAPAN [Access]
External affiliations
Research
Research Outline
Electrochemical devices, such as lithium-ion batteries, operate by the diffusion of ions through a solid. We measure the diffusion coefficients of solid-state battery materials and analyze the ion dynamics in solids/interfaces. We are also developing in-situ measurement techniques to study ion transport mechanisms in solid-state batteries.
Experimental Techniques
Time-of-flight secondary ion mass spectrometry (TOF-SIMS), pulsed field gradient NMR (PFG-NMR), pulsed laser deposition (PLD) Electrochemical methods
Student Recruitment
The NIMS Graduate Research Assistantship is designed for doctoral students who aspire to a career as researchers in materials science. Those students appointed as NIMS Junior Researcher will enable to gain insight into their research career by working on latest research projects. The amount of support is approximately 200,000 yen per month for the doctoral program.
Figure 1: SIMS imaging of lithium isotope distribution. The change in the profile can be used to determine the lithium diffusion coefficient of the battery material. Figure 2: Thin film battery fabricated by pulsed laser deposition and the structural changes observed by in situ Raman spectroscopy.
PublicationsNIMS affiliated publications since 2004.
Research papers
- Naoaki Kuwata, Gen Hasegawa, Daiki Maeda, Norikazu Ishigaki, Takamichi Miyazaki, Junichi Kawamura. Tracer Diffusion Coefficients of Li Ions in LixMn2O4 Thin Films Observed by Isotope Exchange Secondary Ion Mass Spectrometry. The Journal of Physical Chemistry C. 124 [42] (2020) 22981-22992 10.1021/acs.jpcc.0c06375
- Gen Hasegawa, Naoaki Kuwata, Yoshinori Tanaka, Takamichi Miyazaki, Norikazu Ishigaki, Kazunori Takada, Junichi Kawamura. Tracer diffusion coefficients of Li+ ions in c-axis oriented LixCoO2 thin films measured by secondary ion mass spectrometry. Physical Chemistry Chemical Physics. 23 [3] (2021) 2438-2448 10.1039/d0cp04598e
- Naoaki Kuwata, Yasutaka Matsuda, Tatsunori Okawa, Gen Hasegawa, Osamu Kamishima, Junichi Kawamura. Ion dynamics of the Li Mn2O4 cathode in thin-film solid-state batteries revealed by in situ Raman spectroscopy. Solid State Ionics. 380 (2022) 115925 10.1016/j.ssi.2022.115925
Books
- 桑田 直明. 第 4 編 第 6 章 第 6 節 二次電池. (株)エヌ・ティー・エス, 2020
- 桑田 直明, 河村純一. 二次イオン質量分析法による固体電池材料のリチウム拡散係数測定. (株)技術情報協会, 2020
Presentations
- 桑田 直明, 吉田 尚生, 高田 和典. 液相浸透焼結法によるガーネット型酸化物固体電解質の接合. ⽇本化学会第103春季年会(2023)併催シンポジウム「全固体電池のプロセスサイエンス 第2回シンポジウム」. 2023
- 桑田 直明, 長谷川 源, 藤原靖幸, 射場 英紀. PFG-NMRによる固体電解質ニオブ酸ランタンリチウム単結晶の拡散係数測定. 第48回 固体イオニクス討論会. 2022
- 長谷川 佑介, 桑田 直明, 長谷川 源, 松井 広志. K3H(SO4)2の前駆現象におけるプロトンの状態. 第48回固体イオニクス討論会. 2022
Society memberships
The Physical Society of Japan, The Electrochemical Society of Japan, The Solid State Ionics Society of Japan