Visualization of Electrochemical Reactions in All-Solid-State Li-Ion Batteries by Spatially Resolved Electron Energy-Loss Spectroscopy and Electron Holography
Kazuo Yamamoto, Yasutoshi Iriyama, Tsukasa Hirayama
Lithium-ion rechargeable batteries (LIBs) have become essential for business, industry, and daily life. All-solid-state LIBs with incombustible solid electrolytes are expected as next-generation batteries that are safe, long lasting, and have high energy density. The electrochemical battery reactions commonly occur around the electrode/electrolyte interfaces on a nanometer scale; thus, local-scale analysis and observation are important to improve battery performance. Transmission electron microscopy (TEM) is an appropriate technique for such local-scale analysis inside batteries. Here, we introduce two TEM techniques and explain the results of visualizing the dynamics of electrochemical reactions in all-solid-state LIBs. From the results using ex situ spatially resolved electron energy-loss spectroscopy and in situ electron holography, we reveal how Li-ions move in batteries and how they affect the crystal structures, electronic structures, and electric potential during the charge-discharge reactions.