(High-Temperature Energy, Materials, & Processes Division Subhash Singhal Award) From Electrochemical to Mechanical Modeling of SOFCs and Their Experimental Validation

Abstract

Tohoku University has been conducting research on the mechanical reliability of SOFCs under the financial support by NEDO (New Energy and Industrial technology Development Organization, Japan). Both numerical and experimental approaches have been taken at various levels, from electrochemical to structural analyses. An in-house code, SIMUDEL, was developed to simulate oxygen potential distribution inside the constituent materials in order to account for the chemical strain in cell/stack analyses. Non-linear stress-strain behaviors and inelastic deformation of the materials were characterized to improve the accuracy of the simulation. Predicting actual cell behavior, however, is still difficult, as unexpected factors often remain for each specific case. It is thus important to have in-situ or operando tools to observe the behavior of cells, such as deformation and stress generation. For that purpose, laser profilometer and X-ray stress analyzer were employed with a specially designed cell holder. Methods for evaluating local current density was also proposed. Currently, we are developing a protocol for testing robustness of planar SOFCs. Severe condition tests will be performed, and the results will be analyzed with the above-mentioned simulation.