Nanometer-scale mapping of irreversible electrochemical nucleation processes on solid Li-ion electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Electrochemical reactions often involve new phase nucleation and growth, crucial for understanding and controlling processes.
• Current methods struggle to link mechanical conditions, microstructure, and ionic profiles to nucleation kinetics.
• Existing techniques can disrupt microstructures, hindering systematic analysis of microstructure-electrochemical reactivity correlations.

Purpose of the Study:

• To investigate the spatial variability of lithium nucleation on Li-ion conductive glass-ceramics at high resolution.
• To elucidate the factors controlling nucleation kinetics at the nanoscale.
• To establish a method for correlating microstructure with local electrochemical reactivity.

Main Methods:

• Utilized high-resolution (~30 nm) techniques to study irreversible nucleation processes of lithium.
• Examined nucleation on the surface of Li-ion conductive glass-ceramics.
• Analyzed the spatial distribution of nucleation events relative to microstructural features.

Main Results:

• Observed significantly increased lithium nucleation rates at the boundaries between crystalline AlPO4 phases and the amorphous matrix.
• Attributed the enhanced nucleation to localized lithium segregation at these interfaces.
• Demonstrated the ability to probe nucleation mechanisms at the scale of single structural defects.

Conclusions:

• The study reveals that microstructural interfaces play a critical role in controlling lithium nucleation kinetics.
• Lithium segregation at phase boundaries is a key factor driving increased nucleation rates.
• This research provides a pathway for detailed nanoscale analysis of electrochemical activity in materials.