Advanced halide/sulfide all-solid-state lithium metal batteries with fluorinated interface layer.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Interfacial instability between electrolytes and lithium metal anodes hinders solid-state battery development.
• Achieving stable interfaces is crucial for high-performance lithium metal batteries.

Purpose of the Study:

• To develop a stable bilayer solid-state electrolyte with enhanced ionic conductivity.
• To create a robust, artificial solid electrolyte interphase (SEI) on lithium metal anodes.
• To improve the cycling stability and overall performance of all-solid-state lithium metal batteries.

Main Methods:

• Fabrication of a bilayer solid-state electrolyte using Li₃InCl₆ and Li₆PS₅Cl.
• Pre-formation of a LiF-rich SEI on a lithium metal anode using a fluoroethylene carbonate-containing electrolyte.
• Integration of the bilayer electrolyte and pre-treated anode into an all-solid-state lithium metal battery with a LiCoO₂ cathode.

Main Results:

• The bilayer electrolyte exhibited excellent mutual compatibility and high ionic conductivity.
• The pre-formed LiF-rich SEI effectively suppressed interfacial side reactions and ensured stable interfacial contact.
• The assembled all-solid-state lithium metal battery demonstrated exceptional cycling stability, retaining over 85% capacity after 100 cycles at 0.2C.

Conclusions:

• A synergistic strategy combining a compatible bilayer electrolyte and an artificial LiF-rich SEI enables high-performance solid-state lithium metal batteries.
• This dual design significantly enhances interfacial stability, leading to long-lasting and reliable energy storage.
• The findings pave the way for the advancement of safer and more efficient solid-state battery technologies.