Self-Healing Lithium Dendrites through Spontaneous Passivating Layer Formation for Stable Solid-State Lithium-Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• All-solid-state lithium-metal batteries offer high energy density and safety.
• Lithium dendrite penetration through solid electrolytes causes short circuits, a critical failure mode.
• Existing mitigation strategies are often ineffective once dendrite formation begins.

Purpose of the Study:

• To propose and investigate a novel self-healing mechanism to suppress lithium-dendrite propagation in solid electrolytes.
• To utilize lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as a self-healing agent within a Li6PS5Cl solid electrolyte.

Main Methods:

• Incorporation of LiTFSI into a Li6PS5Cl solid electrolyte.
• Experimental analysis to verify self-healing properties and dendrite suppression.
• Testing in a full-cell configuration to demonstrate practical application.

Main Results:

• LiTFSI effectively suppresses lithium-dendrite propagation even after initiation under high current densities.
• Self-healing mechanism forms a passivating layer along particle boundaries upon lithium penetration.
• LiTFSI incorporation increases critical current density by reducing electronic conductivity and promoting a LiF-containing solid-electrolyte interphase.

Conclusions:

• The proposed self-healing mechanism effectively mitigates lithium dendrite propagation in solid-state batteries.
• LiTFSI serves as a promising self-healing agent for enhancing the safety and performance of lithium-metal batteries.
• This approach addresses a critical failure mode, paving the way for more reliable solid-state battery technologies.