Systematic Study on Internal Phenomena of All-solid-state Rechargeable Battery using Silver-ion Marker

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02694
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 32020:Functional solid state chemistry-related
• Research Institution: Ritsumeikan University
• Principal Investigator: ORIKASA Yuki 立命館大学, 生命科学部, 教授 (20589733)
• Co-Investigator(Kenkyū-buntansha): 大石 昌嗣 徳島大学, 大学院社会産業理工学研究部(理工学域), 准教授 (30593587)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 二次電池 / 全固体電池 / X線 / 放射光 / CT / イメージング / デンドライト

Outline of Final Research Achievements

In all-solid-state lithium rechargeable batteries, which are expected to be put into practical use, it is very difficult to observe the movement of lithium ion. In this study, we analyzed the reaction inhomogeneity and metal deposition behavior in all-solid-state batteries by X-ray transmission imaging using silver ions (heavy elements), which are known to diffuse fast in the solid, as a marker. In the all-solid-state battery, it was shown that no concentration change of the solid electrolyte occurred during the charge-discharge reaction. However, in a composite electrode, the insertion/deinsertion reaction of carrier ions preferentially proceeds from the electrode-electrolyte interface, which limits the available electrode thickness. In the case of the metal anode, dendrites grow from even the small crack in the solid electrolyte without grain boundaries.

Free Research Field

固体電気化学

Academic Significance and Societal Importance of the Research Achievements

二次電池内部ではイオンが複雑に動くことで充放電反応が進行する。しかしながら、これを直接観察することは難しく、電池開発の必要な情報が不足していた。本研究では、全固体電池内部で発生するイオンの不均一性や金属析出挙動を、充放電反応中で直接観察する手法を確立し、その現象解明を行った。液体電解質を使用するリチウムイオン電池と比較した時の利点を明確にするとともに、現在抱える全固体電池の課題について反応原理に基づいて示すことに成功した。