Diversifying Ion-Transport Pathways of Composite Solid Electrolytes for High-Performance Solid-State Lithium-Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Solid-state lithium-metal batteries require composite solid electrolytes (CSEs) for enhanced safety and energy density.
• Current CSEs suffer from low ionic conductivity due to limited free lithium ion concentration.
• Improving interfacial interactions in CSEs is crucial for efficient ion transport.

Purpose of the Study:

• To develop an interface design strategy for CSEs to enhance ionic conductivity.
• To improve the compatibility between ceramic fillers and polymer matrices in CSEs.
• To investigate the role of linker structure on lithium salt dissociation and ion transport.

Main Methods:

• Grafting Li$_{7}$La$_{3}$Zr$_{2}$O$_{12}$ (LLZO) ceramic nanofibers onto PVDF-HFP polymer using an amine silane linker.
• Utilizing hydrogen bonding and Lewis acid-base interactions to enhance interfacial properties.
• Systematic study of linker structure's impact on lithium salt dissociation via steric effects.

Main Results:

• Achieved uniform incorporation of 50 wt% LLZO nanofibers into the polymer matrix.
• Enhanced ionic conductivity to 5.8 × 10$^{-4}$ S cm$^{-1}$ through synergistic transport channels.
• Demonstrated improved lithium deposition behavior and regulation in symmetric cells.

Conclusions:

• The proposed interface design strategy effectively enhances CSEs for solid-state lithium-metal batteries.
• The developed CSE exhibits excellent compatibility with LiFePO$_{4}$ and LiNi$_{0.8}$Co$_{0.1}$Mn$_{0.1}$O$_{2}$ cathodes.
• The study provides insights into interface engineering for advanced battery electrolytes.