Li₇La₃Zr₂O₁₂/Polymethacrylate-Based Composite Electrolyte with Hybrid Solid Electrolyte Interphase for Ultra-stable...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Li7La3Zr2O12 (LLZTO)-based electrolytes show promise for solid-state lithium batteries due to their mechanical and electrochemical properties.
• Challenges include poor interfacial contact and uneven lithium deposition, limiting practical applications.

Purpose of the Study:

• To design a flexible composite electrolyte incorporating Ta-doped LLZTO within a polymethacrylate (PMA) matrix.
• To improve interfacial contact and lithium ion transport for high-performance solid-state lithium batteries.

Main Methods:

• Fabrication of a flexible ternary polymethacrylate (PMA) matrix.
• Incorporation of Ta-doped Li7La3Zr2O12 (LLZTO) into the PMA matrix to create LLZTO-PMA composite electrolytes.
• Electrochemical characterization including ionic conductivity measurements and cycling performance in symmetric and full battery cells.

Main Results:

• The LLZTO-PMA composite achieved high ionic conductivity (0.266 mS cm-1 at 20 °C) due to enhanced interfacial contact and fast Li+ pathways.
• A hybrid LiF/Li3N-rich solid electrolyte interphase formed, facilitating rapid Li+ interfacial kinetics.
• Demonstrated an ultra-stable Li anode interphase with >10,000 h lifespan in symmetric cells and >96% capacity retention after 600 cycles in full cells.

Conclusions:

• The LLZTO-PMA composite electrolyte effectively addresses interfacial challenges in solid-state lithium batteries.
• This material offers a breakthrough for developing high-performance and long-lasting solid-state lithium metal batteries.