IR Near-Field Study of the Solid Electrolyte Interphase on a Tin Electrode

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Studying the chemical composition of the solid electrolyte interphase (SEI) on lithium-ion (Li-ion) battery electrodes at the nanoscale is challenging due to limitations in current techniques.
• The SEI layer is crucial for Li-ion battery performance and longevity, influencing ion transport and electrode stability.

Purpose of the Study:

• To demonstrate the capability of infrared apertureless near-field scanning optical microscopy (IR aNSOM) for high-resolution chemical imaging of the SEI layer.
• To investigate the chemical heterogeneity and distribution of SEI components on a model tin (Sn) electrode.

Main Methods:

• Utilized infrared apertureless near-field scanning optical microscopy (IR aNSOM) for nanoscale chemical characterization.
• Applied the technique to image the SEI layer formed on a model Sn electrode in a Li-ion battery system.

Main Results:

• IR aNSOM successfully provided chemical contrast variations within the SEI layer, correlating with surface topography.
• The imaging revealed the distribution of key SEI components, including lithium carbonate and lithium ethylene dicarbonate, on the Sn electrode surface.

Conclusions:

• IR aNSOM is a powerful emerging tool for nanoscale chemical analysis of interfacial layers in Li-ion batteries.
• The study provides insights into the chemical composition and spatial distribution of SEI components, aiding in understanding battery degradation mechanisms.