As Li-ion batteries (LiBs) have become on one of the most reliable power sources, new electrode materials with higher lithium-retention capacity such as tin and silicon-based anodes as well as high voltage oxide or polyanion-type cathodes materials already stand as promising candidates to address the growing need of inexpensive, efficient energy storage systems for the forthcoming energy transition. Despite their initial promising capacity, continuous cycling ineluctably leads to a fading of their performances. The comprehension of failure mechanisms during operation will pave new routes for the design of battery electrode and electrolytes.

This work focusses on the study of interfacial processes at tin anodes, specifically on the dynamics of formation and composition of the solid electrolyte interphase upon cycling. The strategy proposed herein consists in associating enhanced Raman spectroscopy and advanced electrochemistry techniques derived from electrochemical impedance techniques (Quart crystal microbalance and AC electrogravimetry).

We report the compositional study of the SEI ⁽¹⁾ by SHINERS using the plasmon resonance of gold nanoparticles which enhances the Raman signal of the compounds in close vicinity and compensates for the low Raman scattering cross section of the compounds forming the SEI ⁽²⁾. Using SHINs on tin electrodes, Raman signature of the SEI were successfully extracted ex-situ but also in situ through the electrolyte. Composition data are compared to structural information of the SEI extracted by EQCM ^(3,4). Influence of the electrolyte composition on the SEI properties will be detailed during the presentation.

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