2018 Fiscal Year Annual Research Report

Investigations of Fundamental Li-O2 Electrochemistry by In Situ Liquid Cell Transmission Electron Microscopy

Research Project

Project/Area Number	18H05939
Research Institution	Tohoku University
Principal Investigator	韓久慧東北大学, 材料科学高等研究所, 助手 (40823092)
Project Period (FY)	2018-08-24 – 2020-03-31
Keywords	液体セル透過電子顕微鏡 / リチウム空気電池 / その場観察
Outline of Annual Research Achievements	Using in situ liquid cell transmission electron microscopy, we have successfully investigated the reaction dynamics of Li-O2 battery in real-time and real-space. The nanoscale reactions at the electrode-electrolyte interfaces, associated with the formation and decomposition of solid Li2O2 phase, were directly visualized. We found that discharge and charge rate can significantly affect the fundamental mechanisms of Li-O2 reactions. At low rates, the Li-O2 reaction proceeds via a solution mechanism with the formation of Li2O2 layers as thick as ~500 nm. While under high overpotential conditions, a very thin Li2O2 layer forms through a surface mechanism with fast passivation of the electrode surfaces. These findings have advanced our understandings of the fundamental Li-O2 electrochemistry.
Research Progress Status	平成30年度が最終年度であるため、記入しない。
Strategy for Future Research Activity	平成30年度が最終年度であるため、記入しない。