A Simple Approach for Operando Interface Probing for Batteries: Combining Scanning APXPS with Spectroscopic...

Area of Science:

• Electrochemistry
• Surface Science
• Materials Science

Background:

• Probing solid/liquid battery interfaces in situ with APXPS is challenging due to variations in liquid layer properties.
• Accurate interpretation of interfacial spectra requires monitoring the electrochemical and topographical nature of the liquid edge.

Purpose of the Study:

• To develop and validate a methodology combining experimental design and data processing for improved interface probing in batteries.
• To enable accurate characterization of the solid/liquid interface using APXPS.

Main Methods:

• Utilized continuous motion during fixed-mode APXPS measurements to capture the transitional interface.
• Developed two software-based approaches for retrieving interface spectra based on intensity attenuation and peak positions.
• Employed scanning APXPS to extract topographical information and create 3D images of the liquid edge region.

Main Results:

• Identified interface spectra at the edge of intensity transitions and correlated peak energies with chemical features.
• Quantified liquid electrolyte thickness at the interface, revealing a step-jump transition.
• Demonstrated that liquid distribution depends on electrode morphology and chemistry.

Conclusions:

• The developed methodology enhances the understanding of liquid distribution at battery interfaces.
• This approach provides valuable insights into the relationship between liquid distribution and probed interfacial features.
• Validated the functionality of the APXPS setup for in situ interface analysis.