3D Electrode Microstructure Reconstruction and Modelling

Polarization losses within the electrodes are determined both by material composition and microstructure. Analyzing and modelling of electrode-microstructure can help to understand and improve electrodes. In this initial study, the use of a dual-beam focused ion beam/scanning electron microscope (FIB/SEM) for the reconstruction of a high performance LSCF-cathode will be illustrated. Opportunities that arise from this technology for microstructure modelling and possible sources of error will be discussed. From the obtained reconstruction data, the calculation of microstructural parameters like surface area, volume/porosity fraction or tortuosity is possible. Such parameters can be used to calculate cathode performance via microstructure models found in literature (1-4). However, it would be desirable to use the reconstructed microstructure directly in a model in order to investigate the interaction of microstructure and performance more accurately. A three-dimensional (3D) finite element method (FEM) model (5) is presented that allows the analysis and prediction of cathode performance. The model has already been validated, and we will show how to overcome simplifications concerning the microstructure by an extension of the model enabling a direct use of 3D FIB/SEM-data.