2025-10-24 東北大学
図1. オペランドX線CT測定の概要。（左）オペランド（電池動作下）計測セルとその内部のSSLSBセルの構造。比較的低エネルギーの高輝度放射光X線と独自開発した計測セルにより、電池動作中の反応分布の測定を実現した。 （右）X線CTによって得られたSSLSBの3次元再構成像。
＜関連情報＞
- https://www.tohoku.ac.jp/japanese/2025/10/press20251027-01-SSLSB.html
- https://www.tohoku.ac.jp/japanese/newimg/pressimg/tohokuuniv-press20251027_01web_SSLSB.pdf
- https://advanced.onlinelibrary.wiley.com/doi/10.1002/aenm.202503863
充放電サイクル中の固体リチウム硫黄電池における非対称マクロ反応ダイナミクスの解明：オペランドX線コンピュータ断層撮影によるイオン輸送限界の可視化 Unraveling Asymmetric Macroscopic Reaction Dynamics in Solid-State Li–S Batteries During Charge–Discharge Cycles: Visualizing Ionic Transport Limitations with Operando X-Ray Computed Tomography
Yuta Kimura, Mai Tanaka, Shiori Kawasaki, Shoma Yanagihara, Jan Huebner, Nozomu Ishiguro, Takashi Nakamura, Oki Sekizawa, Kiyofumi Nitta, Yoshiharu Uchimoto, Koji Amezawa, Saneyuki Ohno
Advanced Energy Materials Published: 23 October 2025
DOI:https://doi.org/10.1002/aenm.202503863
Abstract
By eliminating liquid electrolytes, solid-state Li–S batteries (SSLSBs) deliver emerging high-energy storage solutions with intrinsic safety advantages. However, restricted access to in-battery reaction dynamics has obscured the mechanisms behind critical limitations in rate capability and cyclability. Here, operando X-ray computed tomography is employed to capture the evolving through-thickness sulfur-lithiation distribution within composite SSLSB cathodes during cycling, directly linking macroscopic ion transport to cell performance. The observations not only demonstrate that macroscopic ion transport severely restricts the rate capability of SSLSBs, but also disclose a previously unreported charge–discharge asymmetry in reaction heterogeneity that triggers irreversible Li2S formation. Differential-evolution fitting of the reaction profiles quantified a deterioration in the effective ionic conductivity during charging, which drives the observed asymmetry and likely arises from electrochemical and/or microstructural degradation of the electrolyte. This study establishes a methodology for high-resolution visualization of reaction dynamics within composite cathodes, providing quantitative insights into the macroscopic transport bottleneck based on experimental observations, which are essential for guiding rational electrode design toward enhanced rate capability and cyclability.
