Fatigue of Li metal anode in solid-state batteries

Area of Science:

• Materials Science
• Electrochemistry
• Mechanical Engineering

Background:

• Solid-state lithium metal batteries (SSBs) offer high energy density and safety for electric vehicles.
• Lithium dendrite growth during cycling causes short circuits, limiting SSB performance and lifespan.

Purpose of the Study:

• To investigate the underlying failure mechanisms in solid-state lithium metal batteries.
• To identify the role of the lithium metal anode in battery degradation and dendrite formation.

Main Methods:

• Operando scanning electron microscopy (SEM) to observe battery behavior during operation.
• Phase-field simulations to model lithium dendrite growth and interface evolution.

Main Results:

• Battery failure is directly linked to the fatigue of the lithium metal anode.
• Lithium anode fatigue significantly contributes to interface degradation and dendrite propagation.
• The observed fatigue behavior follows the Coffin-Manson equation, indicating an intrinsic material property.

Conclusions:

• Lithium metal anode fatigue is an inherent characteristic driving SSB failure.
• Understanding anode fatigue provides a physical basis for SSB failure mechanisms.
• Addressing anode fatigue is crucial for extending the operational lifespan of solid-state lithium metal batteries.