Speaker
Description
Solid oxide fuel cells (SOFCs) are among the most promising energy conversion technologies, as they (i) enable a significant reduction in emissions of air-polluting gases and of carbon dioxide and (ii) simultaneously achieve high energy efficiencies. The overall performance of the fuel cell strongly depends on the porous electrodes - anode and cathode - at which the electrochemical reactions occur. The microstructure of these electrodes is characterized by key factors, such as the material composition and the volume fractions, the n-point correlation functions, the tortuosity, the percolation, and the density of the double or triple phase boundary. The objective of the current work is to present the algorithms that are used to determine these descriptors, which affect the transport of gas, electrons and ions as well as the mechanical behaviour. The computational first-order homogenization is applied to determine the most important physical effective properties, in particular various conductivities, the permeability and the mechanical behaviour including creep. In addition, the open-source tool MCRpy - a differentiable microstructure reconstruction algorithm - is used to characterize and reconstruct the microstructure. A thorough comparison between an original and a reconstructed anode in terms of their geometrical and physical properties will be presented. With the proposed analysis, it is possible to build correlations between geometrical microstructure properties and the resulting effective physical behaviour. Thus, microstructure-property relationships of SOFC electrodes can be established.
