F-Center-Mediated Formation of Metallic Li from Solid Electrolyte Interphases under High-Energy Electron-Beam...

Area of Science:

• Materials Science
• Electrochemistry
• Surface Science

Background:

• The solid electrolyte interphase (SEI) is crucial for anode stability and interfacial kinetics in electrochemical systems.
• Understanding SEI structure-property relationships is vital but challenging due to its sensitivity.
• Electron microscopy offers nanoscale structural characterization but SEI's response to electron beams is poorly understood.

Purpose of the Study:

• To investigate the fundamental response of the SEI to high-energy electron-beam exposure.
• To elucidate the chemical dynamics and transformations occurring within the SEI under irradiation.

Main Methods:

• Utilized advanced electron microscopy techniques for nanoscale structural characterization.
• Investigated the effects of electron-beam irradiation on SEI composition and morphology.

Main Results:

• Observed the precipitation of metallic lithium (Li) from the SEI under electron-beam irradiation.
• Identified F-centers in lithium oxide (Li2O), the primary inorganic SEI component, as the driving force for Li precipitation.
• Demonstrated the reversible transformation of Li back into Li2O induced by the electron beam.

Conclusions:

• Electron-beam irradiation induces significant chemical transformations in the SEI, including Li precipitation and reversible conversion.
• F-center accumulation in Li2O is a key mechanism governing electron-beam-induced SEI dynamics.
• These findings provide novel microstructural insights into the electron-beam-induced chemical dynamics of the SEI.