A Lithium Intrusion-Blocking Interfacial Shield for Wide-Pressure-Range Solid-State Lithium Metal Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Lithium garnets are promising solid-state electrolytes for solid-state Li metal batteries (SSLBs).
• External stack pressure can induce lithium intrusion, leading to premature battery failure.
• Developing methods to mitigate pressure-induced degradation is crucial for SSLB advancement.

Purpose of the Study:

• To develop an in situ constructed interfacial shield to inhibit pressure-induced Li intrusion in SSLBs.
• To investigate the mechanism by which the shield suppresses Li dendrite growth and improves interfacial properties.
• To demonstrate the enhanced performance and high-pressure tolerance of SSLBs protected by the interfacial shield.

Main Methods:

• In situ construction of an interfacial shield comprising metallic Mo nanocrystals and Li2S.
• Theoretical modeling and experimental investigations of shield's effect on Li dendrite growth and interfacial properties.
• Cyclability testing of Li6.4La3Zr1.4Ta0.6O12 (LLZTO)-based SSLBs under various pressures (0.2 MPa to 70 MPa).

Main Results:

• The interfacial shield effectively suppressed pressure-induced Li intrusion and Li dendrite growth.
• Metallic Mo nanocrystals prevented dendrite growth without compromising interfacial contact.
• Li2S component enhanced interfacial wettability and hindered Li dendrite penetration.
• Shield-protected LLZTO-based cells showed significantly enhanced cyclability and stability up to 70 MPa.

Conclusions:

• The in situ constructed interfacial shield is a highly effective strategy to prevent pressure-induced Li intrusion in SSLBs.
• The shield enables robust interfacial stability and superior electrochemical performance under a wide range of pressures.
• This work paves the way for the practical application of SSLBs under demanding operational conditions.