Integrating Lithium Sulfide as a Single Ionic Conductor Interphase for Stable All-Solid-State Lithium-Sulfur...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Lithium 10 germanium phosphorus sulfide (LGPS) is a promising solid-state electrolyte with high ionic conductivity.
• LGPS suffers from self-decomposition and lithium dendrite issues due to incompatibility with lithium metal anodes.
• Interface instability hinders the practical application of LGPS in solid-state batteries.

Purpose of the Study:

• To develop a stable interface between LGPS and lithium metal anodes.
• To enhance the cycle life and performance of all-solid-state lithium-sulfur batteries (ASSLSBs).
• To investigate the role of a Li₂S artificial solid electrolyte interphase (SEI).

Main Methods:

• Facile chemical vapor deposition (CVD) method to create a Li₂S SEI on LGPS.
• Electrochemical characterization including Li plating/stripping tests.
• Performance evaluation of ASSLSBs with the modified interface.

Main Results:

• The Li₂S SEI layer exhibits excellent ionic conductivity and electronic insulation.
• Stable Li plating/stripping was achieved for over 500 hours, demonstrating interface compatibility.
• ASSLSBs with the Li₂S layer showed 90.8% capacity retention after 100 cycles at 0.2 mA cm⁻².
• High reversible capacity (1318.8 mAh g⁻¹) with 88.6% retention was observed at 90 °C after 100 cycles.

Conclusions:

• The Li₂S artificial SEI effectively suppresses self-decomposition and lithium dendrite growth.
• This interface modification strategy significantly improves the stability and cycle life of LGPS-based ASSLSBs.
• The findings offer a new pathway for developing high-performance solid-state batteries.