Figure 3.

In‐situ Raman spectra at selected potentials of the 2nd cycle of modified graphite ‖ AC pouch‐type cells (three‐electrode configuration; RE/QRE: Li metal) between 1200 and 1700 cm⁻¹ with (a) Li‐Pyr (black) and (b) Mg‐Pyr (red) electrolytes at a laser intensity of 1 % (acquisition time: 5×30 s). The corresponding CVs [scan speed: 0.5 mV s⁻¹, cut‐off potentials of 3.4–4.9 V (Li‐ion‐based), respectively 5.0 V vs. Li|Li⁺ (Mg‐ion‐based)] are displayed in Figure S6. At the upper potential of 4.9 V, respectively 5.0 V vs. Li|Li⁺, two spectra recorded before and after a constant potential step of 5 min are shown.