Unraveling the Nanoscale Heterogeneity of Solid Electrolyte Interphase Using Tip-Enhanced Raman Spectroscopy

We employ tip-enhanced Raman spectroscopy (TERS) to study model amorphous silicon (a-Si) thin film anodes galvanostatically cycled for different numbers. For the 1× cycled a-Si, TERS shows good correlation between solid electrolyte interphase (SEI) topography and chemical mapping, corresponding to distribution of lithium ethylene dicarbonate (LEDC) and poly (ethylene oxide) (PEO)-like oligomer species. Subsequent electrochemical cycling makes...