Quantification and Optimization of Interfacial Ion Transport in Polymer/Ceramic Composite Electrolytes for...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Solid polymer/ceramic composite electrolytes are key for solid-state batteries due to their stability and conductivity.
• The interphase between components significantly impacts ionic conductivity, but its contribution is poorly understood.
• Conventional fillers aggregate, hindering uniform interphase formation and transport parameter determination.

Purpose of the Study:

• To quantitatively determine the interphase conductivity in a model polymer/ceramic composite electrolyte.
• To establish design principles for enhancing interphase conductivity for solid-state battery applications.
• To investigate the role of interphase structure and chemistry on ion transport.

Main Methods:

• Fabrication of 3D Li6.4Al0.1La3Zr1.7Ta0.3O12 porous skeletons as fillers.
• In situ polymerization of 1,3-dioxolane to form a composite model system.
• Advanced characterization techniques to determine transport parameters and model interphase conductivity.

Main Results:

• The interphase exhibited a room-temperature conductivity of 2.5 mS cm-1, 33-fold higher than the bulk.
• Lewis acid-base interactions were identified as enhancing interfacial polymerization and Li-ion conduction.
• Optimized interphase conductivity reached 12 mS cm-1 by using Li6PS5Cl as a coating.

Conclusions:

• This study quantifies the critical role of the interphase in composite electrolytes.
• The findings provide fundamental design principles for engineering high-conductivity interphases.
• The developed composite electrolytes show promise for high-energy solid-state batteries.