Improving Bulk and Interfacial Lithium Transport in Garnet-Type Solid Electrolytes through Microstructure...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Chemistry

Background:

• Garnet-type Li6.4La3Zr1.4Ta0.6O7 (LLZTO) is a promising solid-state electrolyte for lithium batteries.
• Key challenges include interfacial issues due to pores and lithium dendrite growth, hindering commercialization.

Purpose of the Study:

• To develop a method for producing high-quality LLZTO with improved microstructure.
• To enhance ionic conductivity and suppress lithium dendrite penetration.

Main Methods:

• Utilized LiAlO2 (LAO) as a chemical additive during LLZTO synthesis.
• Analyzed microstructural properties including grain size, density, and porosity.
• Evaluated interfacial resistance and lithium dendrite suppression.

Main Results:

• Achieved larger grain size (∼25 μm), high relative density (∼96%), and low porosity (∼3.7%).
• Observed continuous secondary phases in grain boundary regions.
• Demonstrated improved Li-ion conductivity and reduced interfacial resistance with Li metal.
• Successfully suppressed Li dendrite penetration.

Conclusions:

• LiAlO2 additive effectively improves LLZTO microstructure and performance.
• Enhanced LLZTO is a viable candidate for safer, high-performance all-solid-state lithium batteries.