Investigating the evolving microstructure of lithium metal electrodes in 3D using X-ray computed tomography

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Electrodeposited lithium microstructures on metallic lithium electrodes hinder rechargeable lithium battery performance and safety.
• Understanding lithium microstructure evolution during battery operation is critical for developing safe and effective lithium-metal batteries.

Purpose of the Study:

• To investigate the morphological evolution of metallic lithium electrode surfaces during battery cycling.
• To characterize the formation of surface pits and mossy lithium deposits.
• To gain insight into microstructural changes and the role of separator architecture.

Main Methods:

• Utilized synchrotron X-ray computed tomography for single cell discharge analysis.
• Employed laboratory X-ray computed tomography for multi-cycle analysis.
• Three-dimensional characterization of lithium electrode microstructures.

Main Results:

• Observed the formation of surface pits on metallic lithium electrodes.
• Characterized the growth of mossy lithium deposits extending through the separator layer.
• Provided 3D insights into microstructural evolution during battery operation.

Conclusions:

• The study elucidates the microstructural evolution of lithium-metal electrodes during rechargeable battery use.
• Findings emphasize the critical role of separator architecture in mitigating lithium dendrite growth.
• This research contributes to the development of safer and more durable lithium-metal batteries.