全固体電池の出力低下の原因を探る新手法を開発 ～リチウム固体電解質の電気二重層効果を電界効果トランジスタで定量評価～
土屋 敬志 主幹研究員（NIMS: 公募A04）
【概要】
東京理科大学理学部第一部応用物理学科の樋口透准教授、物質・材料研究機構国際ナノアーキテクトニクス研究拠点(MANA)の土屋敬志主幹研究員、同機構の寺部一弥MANA主任研究者らの研究グループは、電界効果トランジスタの仕組みを応用した新手法を開発し、従来困難だった固体電解質での電気二重層効果の定量評価に成功しました。全固体電池をはじめとする様々な次世代電池の高出力化への活用が期待されます。本研究成果は、2021年8月6日にシュプリンガー・ネイチャーの化学専門誌「Communications Chemistry」にオンライン掲載されました。
Abstract
The electric double layer (EDL) effect at solid electrolyte/electrode interfaces has been a key topic in many energy and nanoelectronics applications (e.g., all-solid-state Li+ batteries and memristors). However, its characterization remains difficult in comparison with liquid electrolytes. Herein, we use a novel method to show that the EDL effect, and its suppression at solid electrolyte/electronic material interfaces, can be characterized on the basis of the electric conduction characteristics of hydrogenated diamond(H-diamond)-based EDL transistors (EDLTs). Whereas H-diamond-based EDLT with a Li-Si-Zr-O Li+ solid electrolyte showed EDL-induced hole density modulation over a range of up to three orders of magnitude, EDLT with a Li-La-Ti-O (LLTO) Li+ solid electrolyte showed negligible enhancement, which indicates strong suppression of the EDL effect. Such suppression is attributed to charge neutralization in the LLTO, which is due to variation in the valence state of the Ti ions present. The method described is useful for quantitatively evaluating the EDL effect in various solid electrolytes.
Takashi Tsuchiya, Makoto Takayanagi, Kazutaka Mitsuishi, Masataka Imura, Shigenori Ueda, Yasuo Koide, Tohru Higuchi, Kazuya Terabe, Commun. Chem. 4, 117 (2021). "The electric double layer effect and its strong suppression at Li+ solid electrolyte/hydrogenated diamond interfaces"
DOI: 10.1038/s42004-021-00554-7
Published on August 06, 2021
