Keynote Speaker
Prof. Dr. Christine Kranz
Scanning electrochemical probe microscopy studies of solid/electrolyte interfaces
Sven Daboss, Salimeh Saleh, Krishnaveni Palanisamy, Christine Kranz
Institute of Analytical and Bioanalytical Chemistry, Ulm University, Germany
Hard carbon is an attractive anode material for alkali-ion batteries, particularly for sodium-ion batteries (SIBs), due to its high storage capacity and the fact that HC can be produced from renewable bioresources¹. Similar to lithium-ion batteries (LIBs), the performance and operational stability of SIBs is dependent on the electrode electrolyte interphase (SEI)². Although the SEI on graphite anodes (LIBs) and HC anodes (SIBs) have similar chemical properties, it has been shown that the SEI formed on HC is less stable and its stability is strongly dependent on the experimental conditions³. For example, we have recently investigated the SEI formation of spray-coated HC composite anodes in half-cell configurations as a function of the electrolyte (ester and ether based including studies in the presence or absence of fluoroethylene carbonate (FEC) as an additive) ⁴'⁵.
In this contribution, the potential of scanning (electrochemical) probe microscopy (SEPM), such as scanning electrochemical microscopy (SECM), atomic force microscopy (AFM) and hybrid AFM-SECM will be discussed for the characterization of the electrochemical and nanomechanical properties of the SEI.⁵'⁶ In particular, nanopipette-based techniques such as scanning electrochemical cell microscopy (SECCM) are of interest, as the SEI layer can be locally formed on the same HC particle under different experimental conditions (e.g., cycle number, electrolyte , etc.). The formed SEI layer can be further investigated by conductive AFM and AFM force spectroscopy providing insight into the dynamic behavior of the SEI, e.g., dissolution or swelling behavior during cycling.
[1] A. Baldinell et al., Green Chem., 20, 1527-1537, 2018.
[2] E. Peled, S. Menkin, J. Electrochem. Soc. 164, A1703-A1719, 2017.
[3] LA Ma, AJ Naylor, L. Nyholm, R. Younesi, Angew. Chem. Int. Ed. 60, 4855–4863, 2021.
[4] K. Palanisamy et al., Batt. & Supercaps 7, e202300482, 2024.
[5] K. Palanisamy et al., Batt. & Supercaps 7, e202300402, 2024.
[6] S. Daboss, T. Philipp, K. Palanisamy, J. Flowers, HS Stein, C. Kranz, Electrochim. Acta 453, 142345, 2023.
Acknowledgement
This work contributes to the research performed at CELEST (Center for Electrochemical Energy Storage Ulm - Karlsruhe) and was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy – EXC 2154 – Project number 390874152 (POLiS Cluster of Excellence).