Pietro Tanasini

Electrochemical Model of Solid Oxide Fuel Cell for Simulation at the Stack Scale II: Implementation of Degradation Processes

The degradation of the electrochemical performance of solid oxide fuel cell (SOFC) devices is a major hurdle to overcome before commercialisation. The interplay between the phenomena and the long testing times complicate the research, which highlights the relevance of modelling to propose mitigation approaches. This study comprises two parts. This Part II proposes approaches for the simulation of the degradation induced by: (i) interconnect corrosion, (ii) loss of ionic conductivity of the ion-conducting materials, (iii) nickel particle growth in the anode, (iv) chromium contamination and (v) formation of insulating phases in the cathode. The literature survey highlights the lack of data for a completely consistent calibration of the models, despite the simplifications. The support for the implementation is the electrochemical model validated in Part I and a two-dimensional model of the cell and interconnection system. The cathode largely contributes to the degradation. The local overpotential predominantly governs chromium contamination, which can promote the formation of insulating phases, as operation proceeds. The local electronic current density has comparatively a weak direct influence on the degradation. Qualitative agreement with experimental data from the literature could be achieved, without dedicated adjustments of the parameters

Comparison of X-ray Nanotomography and FIB-SEM in Quantifying the Composite LSM/YSZ SOFC Cathode Microstructure

Department of Mechanical Engineering, University of Connecticut, Storrs, CT, USA Electrochemical Engineering Group (GGEC), Centre for Interdisciplinary Electron Microscopy, Industrial Energy Systems Laboratory École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Center Menlo Park, CA 94025, USA National Synchrotron Light Source II, Brookhaven National Laboratory Upton, NY 11973, USA

Analysis of Solid Oxide Fuel Cell LSM-YSZ Composite Cathodes With Varying Starting Powder Sizes

Solid oxide fuel cell cathodes have been examined using non-destructive x-ray nanotomography. The cathodes examined were a composite of strontium-doped lanthanum manganite (LSM) and yttria-stabilized zirconia (YSZ), with three different starting powder sizes of 0.3 μm, 0.5 μm, and 1 μm. Differential absorption contrast imaging was performed over the manganese K-edge (6539 eV) for the identification of the LSM, YSZ, and pore phases. The three phases were each segmented from reconstruction of the tomography data. Three dimensional volumes of the segmented phases were used to calculate structural characterization parameters of the sample including porosity, pore size distributions, and mean phase sizes. These parameters are reported and some correlations are drawn to the starting powder size.Copyright