Regensburg 2025 – wissenschaftliches Programm

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KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 12: Holistic Structural and Safety Assessment of Lithium-ion and Post-Lithium Cells and their Materials (Modelling of Battery Materials and Degradation)

KFM 12.6: Vortrag

Mittwoch, 19. März 2025, 12:30–12:45, H9

Pits and Traps in the Impedance Analysis of Ionic Conductors — •Janis K. Eckhardt — Center for Materials Research (ZfM), Justus Liebig University, Giessen D-35392, Germany

The development of innovative electrochemical storage systems, such as solid-state batteries, is critical for achieving climate neutrality and sustainability goals. Several hurdles must be overcome before such technologies are ready for the market. Impedance spectroscopy is a powerful method for characterizing the electrical transport properties of new materials and for monitoring systems in operation. Although it is an older measurement technique, the interpretation of data for inhomogeneous solid-state systems lacks established concepts for reliable results. Therefore, we use 3D electrical network models for spatially-resolved transport simulations and systematic investigation of the influence of sample microstructure and solid-solid interface morphology. The material-specific transport quantities derived from 1D models (e.g., brick layer model) sometimes exhibit inaccuracies of several orders of magnitude. In addition, the impedance response of the system exhibits geometric signatures that cannot be adequately represented in physically motivated circuit models, e.g., current constriction phenomena.

Keywords: impedance spectroscopy; microstructure; interface morphology; solid-state battery; brick layer model