Argyrodite Solid Electrolyte with a Stable Interface and Superior Dendrite Suppression Capability Realized by ZnO...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Sulfide solid electrolytes (SEs) offer high ionic conductivity but suffer from poor interfacial compatibility with lithium metal and oxide cathodes.
• This limitation hinders the development of stable and high-performance all-solid-state lithium-metal batteries.

Purpose of the Study:

• To enhance the chemical and electrochemical performance of sulfide SEs by employing a ZnO co-doping strategy.
• To improve the interfacial stability and lithium dendrite suppression capabilities of argyrodite electrolytes.

Main Methods:

• Co-doping of argyrodite SEs with ZnO.
• In-depth ex situ analyses to investigate interfacial mechanisms.
• Fabrication and testing of all-solid-state batteries with doped and undoped electrolytes.

Main Results:

• ZnO doping significantly enhances interfacial stability between the argyrodite electrolyte and Li metal, attributed to the formation of LiZn and Li3OBr.
• Reduced electronic conductivity and improved air stability were observed in ZnO-doped SEs.
• All-solid-state batteries utilizing ZnO-doped electrolytes demonstrated higher initial Coulombic efficiency and specific capacity compared to ZnO-free counterparts.

Conclusions:

• ZnO co-doping is an effective strategy to overcome the limitations of sulfide SEs, particularly their interfacial instability.
• The enhanced properties of ZnO-doped SEs pave the way for the development of advanced all-solid-state lithium-metal batteries with improved safety and performance.