Role of Interfacial Defects on Electro-Chemo-Mechanical Failure of Solid-State Electrolyte

Area of Science:

• Materials Science
• Electrochemistry
• Mechanical Engineering

Background:

• Mechanical failure of solid-state electrolytes is a critical issue in lithium metal batteries.
• High stress fields at pre-existing defects during lithium electroplating drive crack propagation and potential short circuits.

Purpose of the Study:

• To investigate the role of interfacial defects in the mechanical failure of solid-state electrolytes.
• To model and visualize stress, damage, and crack formation during lithium plating in defects.

Main Methods:

• Development of an electro-chemo-mechanical model.
• Simulation of lithium electroplating within pre-existing interfacial defects.
• Analysis of stress distribution, relative damage, and crack initiation.

Main Results:

• Interfacial defect geometry is a primary factor in local stress field concentration.
• Semi-spherical defects lead to lower initial damage and longer failure times.
• Defect aspect ratio dictates failure mode: low ratios cause surface pulverization, high ratios cause bulk damage.

Conclusions:

• Understanding interfacial defect geometry is crucial for preventing solid-state electrolyte failure.
• Tailoring defect geometry can enhance the mechanical integrity of solid-state electrolytes.
• Findings provide guidelines for designing robust interfaces in solid-state lithium metal batteries.