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The following data include various measurements using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD). EIS and galvanostatic electrochemical measurements were conducted using a VMP300 potentiostat from Biologic. All SEM measurements were done using a high-Resolution field-emission instrument (GEMINI SEM 560) from Carl Zeiss Microscopy GmbH. For EDS measurements the same SEM was used, coupled with a X-Max Extreme Silicon drift detector from Oxford Instruments. For EBSD measurements the same SEM was used, the microstructural analysis was conducted using a Symmetry 3 EBSD detector from Oxford Instruments. For further informations, please see the "Methods" section of the manuscript.

All data is structured according to the figures presented in the manuscript.

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The following overview summarizes the uploaded data and is intended to help the reader understand it more easily.

Figure 1.zip: Electrochemical data for lithium electrodeposition with and without interlayer. File format .txt.

Figure 2.zip: EDS and EBSD data acquired at the Li|LPSCl interface after Li electrodeposition on the different interlayer materials. File format .h5oina.

Figure 3.zip: Microstructural evolution results based on Monte Carlo Pots simulations. The influence of layer thickness, secondary particle content and substrate grain size was analyzed. The simulation data is given in the respective sub-folders. File format .csv.

Figure 4.zip: Electrochemical data for lithium electrodeposition with subsequent partial stripping with and without interlayer. File format .txt.

Figure 5.zip: Electrochemical data for lithium cycling using a silver interlayer. File format .txt. EBSD data acquired after lithium cycling. File format .h5oina.

Figure 6.zip: Reference to the data structure. File type .txt. Please note that Figure 6 is a schematic, highlighting and summarizing the main findings of the study. This figure is not based on real data.

Supplementary Information Figure 1: Reference to the data structure. File type .txt. Please note that Figure S1 is a schematic, highlighting the cyclic boundary conditions for the Monte Carlo Potts model. This figure is not based on real data.

Supplementary Information Figure 2: Electrochemical data for Coulometric Titration Time Analysis (CTTA) experiments on steel and titanium current collectors.

Supplementary Information Figure 3: Electrochemical data for lithium electrodeposition with interlayers at lower current densities. File format .txt.

Supplementary Information Figure 4: Electrochemical data for coulometric titration experiments with interlayer. EIS measurements after each titration step are included in the respective data file. File format .txt.

Supplementary Information Figure 5: Reference to the data structure. File type .txt.

Supplementary Information Figure 6: Reference to the data structure. File type .txt.

Supplementary Information Figure 7: EBSD data of lithium electrodeposited onto a pristine titanium foil. File format .h5oina.

Supplementary Information Figure 8: EBSD data of lithium electrodeposited onto a gold interlayer. File format .h5oina.

Supplementary Information Figure 9: Reference to the data structure. File type .txt.

Supplementary Information Figure 10: EBSD data of lithium electrodeposited onto a silver interlayer. File format .h5oina.

Supplementary Information Figure 11: EBSD data of lithium electrodeposited onto a bismuth interlayer. File format .h5oina.

Supplementary Information Figure 12: Reference to the data structure. File type .txt.

Supplementary Information Figure 13: XRD data of an ex-situ prepared Li(Ag) solid solution sample together with lithium foil references. File format .xy.

Supplementary Information Figure 14: Microstructural evolution results based on Monte Carlo Pots simulations. The influence of substrate roughness was analyzed. File format .csv.

Supplementary Information Figure 15: EBSD data of lithium electrodeposited and subsequently partially stripped on a pristine titanium foil. File format .h5oina.

Supplementary Information Figure 16: Reference to the data structure. File type .txt.

Supplementary Information Figure 17: Reference to the data structure. File type .txt.

Supplementary Information Figure 18: Electrochemical data for lithium electrodeposition with and without subsequent partial Stripping on a pristine titanium foil. File format .txt. EBSD data for lithium layers electrodeposited for 5 mAh cm-2 and 10 mAh cm-2. File format .h5oina.

Supplementary Information Figure 19: EBSD data of lithium electrodeposited and subsequently partially stripped on a gold interlayer. File format .h5oina.

Supplementary Information Figure 20: EBSD data of lithium electrodeposited and subsequently partially stripped on a silver interlayer. File format .h5oina.

Supplementary Information Figure 21: EBSD data of lithium electrodeposited and subsequently partially stripped on a silver interlayer at lower areal charges. File format .h5oina.

Supplementary Information Figure 22: EBSD data of lithium electrodeposited and subsequently partially stripped on a bismuth interlayer. File format .h5oina.

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Information about the data file type for EDS and EBSD data

The acquired EDS data are stored in a Oxford Instruments NanoAnalysis HDF5 file format (.h5onia) and can be accessed through Oxford Instruments' AZtec software or compatible third-party software.

For further insights into the file structure, we refer the reader to the following link:

https://github.com/oinanoanalysis/h5oina