Long-Life All-Solid-State Batteries Enabled by Cold-Pressed Garnet Composite Electrolytes with Enhanced Li⁺...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Garnet Li7La3Zr2O12 (LLZO) is a promising solid-state electrolyte (SSE) for high-energy-density lithium metal batteries.
• High-temperature sintered LLZO is brittle, while cold-pressed LLZO has low ionic conductivity.
• Developing ductile and conductive SSEs is crucial for practical all-solid-state batteries.

Purpose of the Study:

• To create a ductile and highly conductive cold-pressed solid-state electrolyte.
• To improve the interfacial properties between ceramic and sulfide electrolytes.
• To enhance the performance and safety of lithium metal batteries.

Main Methods:

• Fabrication of cold-pressed tantalum-doped LLZO (Ta-LZ) particles.
• Integration of Ta-LZ with ductile lithium thiophosphate chloride (LPSC) via a Li+ conductive Li-containing Ta-Cl structure.
• Characterization of ionic conductivity, activation energy, and electrochemical performance in Li symmetric cells.

Main Results:

• The composite Ta-LZ/LPSC SSE exhibits a Li+ conductivity of 4.42×10^-4 S/cm and a low activation energy of 0.31 eV.
• The composite demonstrates excellent Li dendrite suppression with a critical current density of 5.0 mA/cm^2.
• Li symmetric cells achieved a cycle life exceeding 600 hours at 1 mA/cm^2.

Conclusions:

• The developed Ta-LZ/LPSC composite offers a promising solution for creating ductile and conductive cold-pressed ceramic electrolytes.
• This approach enhances interfacial Li+ exchange, creating a continuous conduction pathway.
• The findings provide valuable insights for fabricating high-performance all-solid-state batteries.