Direct observation of electrode reaction by in-situ STEM technique and the designing of ideal electrodes

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H05967
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Nanomaterials chemistry
• Research Institution: Nagasaki University
• Principal Investigator: URITA Koki 長崎大学, 工学研究科, 准教授 (40567666)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: in-situ 電子顕微鏡観察 / リチウムイオン二次電池 / 電気二重層キャパシタ

Outline of Final Research Achievements

This study dealt with the clarification the details of the electrochemical interfacial reaction between electrodes and electrolyte from a structural viewpoint, and designed an ideal electrode providing high performance in electric double layer capacitors and Li-ion rechargeable batteries. The structures of porous carbon electrode and the composite electrode with active material such as SnO2 and sulfur, was accurately characterized by gas/vapor adsorption isotherm, temperature-programmed desorption, X-ray diffraction and high-resolution scanning transmission electron microscopy. Here ideal structures were proposed by linking the electrochemical performance with the structural information. And also, this study established an in-situ electron microscopy observation under electrochemical measurement in order to trace the electrochemical reaction on the electrode interface.

Free Research Field

ナノ構造解析

Academic Significance and Societal Importance of the Research Achievements

電極活物質界面，電極空間内における局所的な充放電プロセスは，詳細な電極構造と電気化学特性の関係を正確に理解する必要があり，これまでに十分な知見が得られていなかった。本研究では，電極反応場として利用されているナノ空間の構造及び担持した活物質の状態を明らかにし，高容量・高サイクル特性に必要な反応場を提唱した。この様な反応場の提唱はデバイスの高性能化につながる電極材料の設計に直結する。また，電極界面の現象解明に向けた電子顕微鏡による電極反応のその場観察技術の確立を行った。本手法が広く普及することで電極反応だけでなく，液中の状態解明をより高精度に行うことが可能となる。