Improved Ionic Conductivity and Li Dendrite Suppression Capability toward Li₇P₃S₁₁-Based Solid Electrolytes Triggered...

Area of Science:

• Solid-state electrochemistry
• Materials science
• Energy storage

Background:

• Sulfide solid electrolytes face challenges in simultaneously improving ionic conductivity, dendrite suppression, and interfacial compatibility.
• Achieving stable interfaces is crucial for high-performance solid-state batteries.

Purpose of the Study:

• To develop a novel solid electrolyte with enhanced properties for all-solid-state lithium-sulfur batteries.
• To investigate the effect of niobium (Nb) and oxygen (O) cosubstitution on the performance of Li7P3S11-based electrolytes.

Main Methods:

• Synthesis of a novel Li7P2.88Nb0.12S10.7O0.3 solid electrolyte via cosubstitution of glass-ceramic Li7P3S11.
• Characterization of ionic conductivity, critical current density, and interfacial compatibility.
• Fabrication and testing of all-solid-state Li/Li2S batteries.

Main Results:

• The novel electrolyte exhibits high ionic conductivity (3.59 mS cm-1 at 298 K) and improved critical current density (1.16 mA cm-2).
• Excellent interfacial compatibility was observed between the sulfide electrolyte and Li2S active material.
• The interface formed with metallic lithium shows enhanced electrochemical stability due to Nb and Li2O formation, promoting uniform Li deposition.

Conclusions:

• Nb and O cosubstitution effectively enhances the performance of sulfide solid electrolytes.
• The developed solid electrolyte enables all-solid-state Li/Li2S batteries with superior cycling stability and rate performance.
• This work offers a promising strategy for developing next-generation solid-state batteries.