Nanoscale Characterization of Energy Materials

We are investigating the microscopic properties of all-solid-state batteries in order to make them ready for use in the future.  In these batteries interfaces are present between a lithium-ion reservoir, a solid electrolyte, and a lithium-ion collector. Our research focuses on the microscopic properties of these interfaces and additional interphases that may form during operation. We apply advanced Scanning Force Microscopy methods on common all-solid-state battery model systems during operation. These methods enable us to determine the chemical composition and mechanical properties of interphases. In addition, we studied charge transport across interfaces by operando Kelvin Probe Force Microscopy (KPFM). We discovered initial aspects of dendritic growth in a Li_6.25Al_0.25La₃Zr₂O₁₂ garnet-type solid electrolyte. Using in operando KPFM, we investigated the Galvani potential distribution across thin-film all-solid-state batteries. Thereby, we measured and followed the space charge layer evolution in a model Li (Lithium)|Li₃PO₄ (lithium phosphate)|LiCoO₂ (lithium cobalt oxide) thin film battery at different states of charge in the voltage range from 3.0 V to 4.3 V vs Li⁺/Li (Figure). 

Advanced Scanning Force Microscopy methods - such as KPFM - are not commonly used in battery research, although these techniques revealed valuable interfacial information on the behavior of all-solid-state batteries in operation. In the future, advanced Scanning Force Microscopy methods can potentially be used to investigate a variety of solid electrolyte-based systems, even with additional interphase formation at interfaces. 

1. Shi, B.X., Weber, F., Yusim, Y., Demuth, T., Vettori, K.,  Münchinger, A., Titvinidze, G., Volz, K., Henss, A., Berger, R., Richter, F.H., Lithiated polymer coating for interface stabilization in Li6PS5Cl-based solid-state batteries with high-nickel NCM, J. Mater. Chem. A, 2025,13, 2600-2614, DOI: 10.1039/D4TA07265K
2. Xiaotang Shi, Andrew Naylor, Till Fuchs-Kühn, Steffen Schröder, Franjo Weber, Hans-Jürgen Butt, Rüdiger Berger, Mechanical Properties of Cathode-Electrolyte Interphase Layers in High-Voltage Lithium-Ion Batteries, submitted 2026. 
3. Weber, F., Zhu, C., Kobayashi, S., Fuchs, T., Hitosugi, T.,  Janek, J. & Berger, R. (2025).  Interpretation of Kelvin Probe Force Measurements in Solid-State Electrochemical Cells, ACS Appl. Mater. Interfaces 2025, 17, 42, 58825–58836. DOI: 10.1021/acsami.5c10182
4. Zhu, C., Fuchs, T., Weber, S.A.L., Richter, F.H., Glasser, G.,  Weber, F., Butt, H.-J.,  Janek, J. & Berger R. (2023). Understanding the evolution of lithium dendrites at Li6.25Al0.25La3Zr2O12 grain boundaries via operando microscopy techniques, Nature Communications 14, 1300 (2023). DOI: 10.1038/s41467-023-36792-7 
5. Zhu, C., Kobayashi, S., Sugisawa, Y., Weber F., Lin, K.-H., Kitamura M., Horiba K., Kumigashira H., Nishio K., Shimizu R., Sekiba D., Hitosugi T. & Berger R. (2025). Space Charge Layer Evolution in All-Solid-State Batteries Probed via Operando Kelvin Probe Force Microscopy and Nuclear Reaction Analysis, ACS Nano 2025, 19, 45, 39062–39075. DOI: 10.1021/acsnano.5c10125