Double-Faced Bond Coupling to Induce an Ultrastable Lithium/Li₆PS₅Cl Interface for High-Performance All-Solid-State...

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Sulfide solid electrolytes (SSEs) are promising for all-solid-state lithium metal batteries (ASSLMBs) due to high ionic conductivity and mechanical strength.
• However, poor interfacial stability between lithium anodes and SSEs, along with lithium dendrite growth, hinders commercialization.

Purpose of the Study:

• To introduce a novel amphiphilic solid electrolyte interphase (SEI) layer at the Li/SSE interface.
• To enhance the stability and performance of ASSLMBs by preventing side reactions and dendrite formation.

Main Methods:

• Fabrication of an amphiphilic LiSiO-enriched SEI layer.
• Characterization of interfacial bonding using techniques like in situ microscopy.
• Testing of symmetric cells for cycling performance and interfacial stability.

Main Results:

• The LiSiO-enriched SEI layer forms covalent bonds (Li-S, Li-O-Si, Si-S) with both Li anode and SSEs, termed the 'pincer effect'.
• This interface effectively suppresses side reactions and lithium dendrite growth.
• Symmetric cells demonstrated stable cycling over 2000 hours at 0.2 mA cm⁻² and 500 hours at 0.5 mA cm⁻² without significant resistance increase.

Conclusions:

• The developed artificial SEI layer with the 'pincer effect' significantly improves interfacial stability in ASSLMBs.
• This approach offers a new strategy for the commercialization of high-performance ASSLMBs.