Upon completing both sets of electrochemical experiments, the electrodes were rinsed with a PC solution, using SDC system to remove any residual dried electrolyte. After drying, an ex-situ XPS analysis was performed on the initial experimental set to evaluate the development of the CEI. This analysis identified various species and functional groups, as demonstrated in Figure . 4a across all panels, which presents the spectra from sample 1 (S1) of this set. The C --C peak, representative of the conductive carbon at the electrode surface, was selected as the reference with a relative concentration of 1. All subsequent signals are scaled and normalized to this benchmark.