CP was used for charging and discharging a gold WE. The charge profile shows a potential drop at the beginning of the charging process due to the alloy nucleation followed by two plateaus, and the discharge profile includes three plateaus . The capacity loss during the cycling and low coulombic efficiency might be attributed to the loss of active material due to extreme volume changes and SEI formation, which is commonly observed for alloy-type anodes . For the measurement on the unmasked substrate, most of the CP curves have identical shapes. However, some outliers in charged and discharged capacities were observed (Figure ), since the inconsistent contact between the cell and WE, led to the leakage of the electrolyte around the tip and the formation of a meniscus (Figure ). Electrolyte leakage and spreading over the substrate can be explained by the relatively high surface energy of gold metal and lower surface tension of ester electrolyte solvents in comparison with aqueous systems . Optical microscopy images were acquired to investigate the leakage effect and correct the wetted area. Although the majority of the measurement points displayed a reproducible wetted area (Figure and S6), some spots had noticeable electrolyte leakage (Figure and). Areas directly exposed to the electrolyte exhibit different colors from those under sealing contact and the leakage area in the optical micrographs (Figure and). The variation between colors among these three areas might be attributed to the inhomogeneous lithiation and delithiation reactions, as well as SEI formation. The exact determination of the wetted area for some measurement points was a challenging task since the boundary between reacted and non-reacted areas is not pronounced. The specific capacity values, corrected by the wetted area and areal loading, exhibit less variance (Figure ). After the correction, the leaked spots demonstrate lower specific capacity, which could be due to changes in ionic conductivity caused by electrolyte evaporation in a leaked area, and incomplete charge and discharge processes resulting from the separation of leaked and non-leaked area by tip sealing. The coulombic efficiency for the first and second cycles is consistent over all experiments (Figure ). However, even if the wetted area would be measured after the measurement, still the charge or discharge rate (in current per area or mass) would be different between measurement points, leading to additional deviations in the capacity values. OCP procedure was used to equilibrate the electrochemical system after the contract with WE and before EIS. OCP measurement can be used as a quick method for poor contact detection between WE and electrolyte and potential stabilization before the EIS measurement. OCP was stabilized during ca. 1 minute after the cell contact with the substrate and ca. 5 minutes after CP measurement (Figure ). OCP could be also used to detect RE drift (Figure ). The OCP lower than 1.0 V after the end of the second discharge could be attributed to non-complete delithiation (Figure ).