Multi-scale microstructure characterization on inert supported solid oxide fuel cells
The solid oxide fuel cell (SOFC) offers a great potential for stationary energy conversion applications because of its high combined heat and power efficiency. It is of significant interest to understand performance relevant aspects of both material selection and manufacturing optimization. A design, which is made by co-sintering of inert substrate and functional layers, offers great possibilities for further methodological development. Findings can be transferred to different cell concepts. To understand and link fabrication parameters to the cell performance and identify aging mechanisms, sophisticated investigation of the 3D microstructure is necessary.
This contribution will demonstrate how advanced correlative multiscale tomography can be used to identify microstructural parameters ranging from millimeter to nanometer scale. We combine optical microscopy (OM), X-ray computed tomography (μ-CT), focused ion beam – scanning electron microscopy (FIB-SEM) tomography and energy dispersive X-ray spectroscopy - scanning transmission electron microscopy (EDXS-STEM). The resulting microstructure data can be used to visualize performance critical cell areas such as inhomogeneities and secondary phases. In addition, pore and tortuosity distributions obtained from data of different length scales allow modeling of gas diffusion losses of all cell layers. This exemplifies how correlative tomography helps to understand specific contributions to overall cell performance.