Using Thermal Interface Resistance for Noninvasive Operando Mapping of Buried Interfacial Lithium Morphology in...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• The lithium metal-solid-state electrolyte interface is vital for solid-state battery performance.
• Direct characterization of this buried interface during operation is challenging due to limited optical access.
• Existing destructive techniques alter the interface, preventing operando monitoring.

Purpose of the Study:

• To develop a noninvasive method for probing the morphology of the lithium metal-solid-state electrolyte interface.
• To enable operando monitoring of interface evolution in solid-state cells.

Main Methods:

• Introduction of thermal wave sensing using modified 3ω (3-omega) sensors.
• Attachment of sensors to the exterior of lithium metal-solid-state cells.
• Measurement of thermal interface resistance to correlate with interface morphology.

Main Results:

• Demonstrated that measured thermal interface resistance directly relates to the physical morphology of the interface.
• Validated the use of 3ω thermal wave sensing for noninvasive operando monitoring.
• Showcased the ability to track morphology evolution of the lithium metal-electrolyte interface over time.

Conclusions:

• Thermal wave sensing offers a noninvasive approach to study solid-state battery interfaces.
• This technique overcomes limitations of optical and destructive methods for operando characterization.
• 3ω thermal wave sensing is a promising tool for understanding and optimizing solid-state battery interface behavior.