Characterization and analysis methods for the examination of the heterogeneous solid oxide fuel cell electrode microstructure. Part 1: Volumetric measurements of the heterogeneous structure

Advanced imaging and characterization methods have permitted the 3-D and phase-specific reconstruction of dense and opaque samples with features that have a length scale on the order of tens of nanometers and comprised of materials with large X-ray mass absorption coefficients. Engineered materials, like those found in solid oxide fuel cell (SOFC) electrodes, use complex materials that have often limited opportunities to perform 3-D characterization and analysis. Still, characterization and analysis methods are needed to better understand these structures and their functional impact. The development, verification, and validation of methods used by the authors for the characterization and analysis of the heterogeneous SOFC anode are discussed in this work [1] and [2]. These methods include the measurement of the volume fractions of the individual phases, contiguity or volumetric connectivity, tortuosity, and interfacial properties. A second and complementary part of this work will examine quantitative methods that provide detailed descriptions of the structure and its relations to the transport processes that it must support [3]. These efforts are intended to describe the formulation of methods developed to provide insight into the SOFC anode nano/microstructure.