Ultrafast Laser Spectroscopy of Electrode/Electrolyte Interfaces

Direct chemical analysis of electrode/electrolyte interfaces can provide critical information on surface phenomena that currently limit the performance of Libased battery systems [1-5]. In this work we introduce the use of ex situ femtosecond (fs) Laser Induced Breakdown Spectroscopy (LIBS) to probe compositional variations within the Solid Electrolyte Interphase (SEI) layer [6-8]. Nanometer-scale depth resolution was achieved for elemental and molecular depth profiling of SEI layers formed on Highly Oriented Pyrolytic Graphite (HOPG) electrodes in an organic carbonate-based electrolyte. This work demonstrates the use of ultrafast laser spectroscopy as a highly versatile, light element-sensitive technique for direct, real-time chemical analysis of interfacial layers in electrochemical energy storage systems.