Soutenance de thèse SOLEIL - Federico CAPONE - 05/04/2024-14h00 - Grand Amphi SOLEIL

Investigating the SEI formation in Li-ion batteries using novel in situ XPS-based approaches

Federico CAPONE
(Ligne GALAXIES, Synchrotron SOLEIL, Gif-sur-Yvette)                                      

Vendredi 5 avril 2024 – 14h00 - (Amphithéâtre SOLEIL)             

The solid electrolyte interphase (SEI) formation between the electrode and electrolyte is crucial for Li-ion battery functionality. It expands the electrodes' thermodynamic window, enabling higher voltages and enhancing battery performance. SEI stability prevents electrolyte species decomposition, ensuring extended battery life, improved stability, and enhanced safety. However, the complex processes governing SEI formation remain under investigation.

X-ray photoelectron spectroscopy (XPS) is a suitable technique for studying SEI formation due to its chemical and surface sensitivity. Yet, experimental constraints, such as photoelectron detection and ultra-high vacuum environments, may limit its use with liquid electrolytes and hinder buried interface studies. Innovative XPS approaches, leveraging X-ray synchrotron techniques, offer potential solutions.

This study employs two novel spectroscopic methods:
Near-ambient pressure XPS (NAP-PES) with a Dip & Pull setup to assess electrolyte formulation influences on HIPPIE beamline at MAX-IV.
Development of a tailored in situ cell for high kinetic energy XPS (HAXPES) to study SEI under realistic electrochemical conditions for GALAXIES beamline of SOLEIL