Looking at low-frequency regions in Figure and b, we observe differences in the inclination of the Nyquist plot for the different samples. Contrary to perfect non-faradaic processes, the transition of the Rion region to lower frequencies should be a constant real impedance. This inclination tendency could be due to a small charge-transfer resistance of the anions ClO4 -present in the electrolyte (10 mM TBAClO4 in 1:1 wt% EC:DMC). Nevertheless, EC solvates the anion slugging the intercalation. Abbas et al. reported that anions ClO4 -could intercalate the graphite sheets (capacity = 20 mAh/g) when using a highly concentrated aqueous electrolyte because of Gr defects and lower crystallinity. Calendering impacts the cycling performance in the electrode. Consequently, we evaluated the electrochemical cycling (normalized charge capacity vs. cycle number) for the Si8%/Gr83% and Si15%/Gr76% formulations (see Figure and b, respectively) for the pristine and calendered electrodes. More details on the electrochemical cycling procedure can be found in Methods.