Multi-scale characterization of ceramic inert-substrate-supported and co-sintered solid oxide fuel cells

Understanding cell performance is essential for selecting cell components and the processing parameters for solid oxide fuel cells. The scale of relevant microstructural features in electrodes, electrolyte and supporting substrate covers several orders of magnitude. This contribution will demonstrate how advanced correlative multi-scale tomography can be used to identify those parameters: ranging from millimeter to nanometer scale. We employ optical microscopy, X-ray computed tomography (μ-CT), focused ion beam-scanning electron microscopy tomography and energy-dispersive X-ray spectroscopy– scanning transmission electron microscopy. Additional investigations by selected area electron diffraction allow a determination of the underlying crystal structures. An SOFC design based on the co-sintering of an inert substrate with various functional layers on top is used as a blueprint, allowing further methodological development. The effect of interdiffusion between phases and development of secondary phases on microstructure and chemical composition will be shown. Furthermore, porosity and tortuosity extracted individually from all porous layers will allow modeling of gas diffusion loss contributions within the co-fired cell structure. ... mehrThis exemplifies how correlative tomography helps to understand specific contributions to overall cell performance.