Visualization of Electric Potential Around Electrode/Solid-Electrolyte Interfaces by Operando Electron Holography

Electron holography is a transmission electron microscopy technique used to quantitatively visualize electric potential distributions in functional materials and devices. In this chapter, we first introduce the observation techniques for application in all-solid-state batteries under operating conditions. Then, we describe the principles of electron holography and the physical significance of potentials used in electrochemistry and electron microscopy, elucidating the physical quantity detected by electron holography. Finally, we show the electric potential distributions around the cathode/solid-electrolyte interfaces and also show how Li-ions move in the batteries during charge and discharge cycles.