Visualizing the Interfacial Chemistry in Multivalent Metal Anodes by Transmission Electron Microscopy

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Multivalent metal batteries (MMBs) are emerging as promising alternatives to Li-ion batteries due to their potential for high energy density and lower cost.
• A key challenge hindering MMB performance is the instability of the solid electrolyte interphase (SEI) during metal plating and stripping, leading to low Coulombic efficiency and short cycle life.
• Understanding the SEI's chemical and structural properties is critical for developing stable and practical MMBs.

Purpose of the Study:

• To provide a comprehensive overview of the state-of-the-art understanding of interphases in MMBs.
• To highlight the application of transmission electron microscopy (TEM) techniques in characterizing these interphases.
• To elucidate the features of interphases on various multivalent metal anodes and propose future research directions.

Main Methods:

• Utilizing operando and cryogenic transmission electron microscopy (TEM) for high spatial and temporal resolution imaging.
• Analyzing the dynamic visualization of vulnerable chemical structures within interphase layers.
• Scrutinizing the interphases formed on different multivalent metal anodes (e.g., Zn, Ca, Mg).

Main Results:

• TEM methods enable dynamic visualization of the SEI's chemical structures and evolution.
• Distinct interphase features have been identified across different multivalent metal anodes.
• Insights into the interfacial chemistry are gained, crucial for understanding performance limitations.

Conclusions:

• Transmission electron microscopy is a powerful tool for fundamental studies of interphases in MMBs.
• Understanding and regulating interphase chemistry is essential for advancing practical MMB technology.
• Further research is needed to address remaining challenges in interphase analysis and control for MMBs.