Disorder-driven sintering-free garnet-type solid electrolytes.

Area of Science:

• Materials Science
• Electrochemistry
• Solid-state Chemistry

Background:

• High-temperature processing of oxide ceramic electrolytes for lithium metal batteries can cause material degradation.
• Conventional methods for synthesizing garnet electrolytes require high temperatures (>1100°C), limiting their practical application.

Purpose of the Study:

• To introduce a disorder-driven, sintering-free synthesis route for garnet-type solid electrolytes.
• To enable the fabrication of reliable and thin solid electrolyte membranes for high-energy lithium metal batteries.

Main Methods:

• Creation of an amorphous matrix from disordered base materials.
• Single-step mild heat treatment at 500°C to induce crystallization.
• Characterization of mechanical properties and ionic conductivity.

Main Results:

• Achieved cubic-phase garnet formation at a lowered temperature of 350°C.
• Obtained a Li+ ionic conductivity of 1.8 × 10-4 S/cm at 25°C.
• Demonstrated softened mechanical properties (yield pressure = 359.8 MPa) facilitating dense matrix formation.

Conclusions:

• The disorder-driven garnet solid electrolyte exhibits electrochemical performance comparable to conventionally sintered electrolytes.
• This sintering-free approach overcomes limitations of high-temperature processing, promoting the commercialization of oxide-based lithium metal batteries.
• The method facilitates the production of uniform, thin, and wide solid electrolyte membranes.