A High-Performance Garnet-Based All-Solid-State Battery Fabricated Through Room-Temperature Ultrasonic Welding

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Garnet-type Li6.5La3Zr1.5Ta0.5O12 (LLZO) shows promise for Li metal batteries due to high ionic conductivity and Li metal stability.
• Poor interfacial contact and lithium dendrite growth limit LLZO's practical application in solid-state batteries.

Purpose of the Study:

• To develop an efficient strategy to overcome interfacial challenges in LLZO-based solid-state batteries.
• To improve the performance and cycling stability of solid-state batteries using LLZO electrolytes.

Main Methods:

• A novel room-temperature ultrasonic treatment was applied to a LiMg alloy anode.
• Fabrication of symmetrical UW-LiMg/LLZO/UW-LiMg cells and all-solid-state UW-LiMg/LLZO/LiFePO4 batteries.
• Electrochemical characterization including critical current density, cycling stability, and capacity retention measurements.

Main Results:

• The UW-LiMg/LLZO/UW-LiMg cell achieved a low interfacial resistance and a critical current density of 4.45 mA cm⁻².
• Cells demonstrated stable Li plating/stripping for over 1000 h at 1 mA cm⁻² with low overpotential (≈30 mV).
• The all-solid-state battery delivered 153 mAh g⁻¹ at 0.5 C and 90% capacity retention after 200 cycles.

Conclusions:

• Ultrasonic treatment of LiMg alloy anodes enhances ductility and forms a stable interface, significantly improving LLZO-based battery performance.
• This strategy effectively suppresses lithium dendrites and boosts critical current density, paving the way for practical solid-state batteries.