Metal Electroplating/Stripping and 4D STEM Analysis Revealed by Liquid Phase Transmission Electron Microscopy

Abstract

Aqueous zinc ion and metal-based batteries have attracted much attention towards the development of an alternative electrochemical energy storage technology beyond lithium ion batteries [1]. There are several advantages of metal-based batteries, including high volumetric capacity (∼8000 mAh/L), low anode potential (∼0.7 V vs. SHE), safety and electrode abundance. However, the problem of metallic dendrite growth during cycling can cause battery short circuit failure, which can result in safety hazards and severely limit the progress and further commercialization [2, 3]. To this end, direct visualization of dendrite evolution under operando conditions is a prerequisite for battery safety and longevity. Among the many operando/in situ techniques, the use of liquid phase transmission electron microscopy (LPTEM) [4] has been very effective in enabling a more detailed understanding of metal plating and stripping, where the ability to locally probe and visualize the key processes governing the dendrite formation. However, it remains challenging to perform high resolution and analytical electron microscopy studies in a liquid cell, especially under liquid flow conditions.