Lithium ion diffusion measurements on a garnet-type solid conductor Li6.6La3Zr1.6Ta0.4O12 by using a pulsed-gradient...

Area of Science:

• Solid-state chemistry
• Materials science
• Electrochemistry

Background:

• Garnet-type solid conductors, such as Li7-xLa3Zr2-xTaxO12, are recognized for their high ionic conductivity.
• These materials are crucial for developing advanced energy storage devices.

Purpose of the Study:

• To synthesize and characterize Li6.6La3Zr1.6Ta0.4O12 (LLZO-Ta) with enhanced ionic conductivity.
• To investigate the dynamics of lithium ion diffusion in LLZO-Ta using advanced NMR techniques.

Main Methods:

• Synthesis of cubic Li6.6La3Zr1.6Ta0.4O12 (LLZO-Ta).
• Characterization using (7)Li Nuclear Magnetic Resonance (NMR) spectroscopy.
• Lithium ion diffusion measurements via pulsed-field spin-echo (PGSE) NMR spectroscopy.

Main Results:

• Achieved high ionic conductivity of 3.7×10(-4)Scm(-1) at room temperature for LLZO-Ta.
• Observed temperature-dependent changes in the (7)Li NMR linewidth, indicating dynamic Li+ ions.
• PGSE NMR revealed lithium diffusion dependent on observation time and pulsed-field gradient strength, distinct from liquid diffusion.

Conclusions:

• Lithium ion migration in LLZO-Ta is complex, exhibiting wide spatial and temporal distributions.
• The findings provide critical insights into ion transport mechanisms in solid electrolytes.
• This research contributes to the development of safer and more efficient solid-state batteries.