Stress Analysis of Solid Oxide Fuel Cell Electrodes Using Functional Gradient Materials

Abstract

The differences in material properties of different components of solid oxide fuel cells cause high stresses during sintering and operation, functional gradient material electrodes are expected to alleviate this problem. In this study, electrodes with three different material compositions are compared with electrodes using conventional materials, and the residual and thermal stresses are calculated by applying functional gradient materials to single-sided and double-sided electrodes, respectively, and the results are analyzed with the optimization goal of minimizing the stresses to find the optimal functional gradient material composition distribution. The study shows that the functional gradient material electrode can significantly reduce the interfacial stress and alleviate the local stress concentration. When using functional gradient materials for one side of the electrode, a specific material component distribution can reduce the residual stress and thermal stress on the other side, but the stresses may increase on the local side of the electrode. The interfacial stress between layers can be reduced to a maximum of 0.1 MPa when a functional gradient material with a quadratic linear distribution of components is used for both sides of the electrodes. This study has implications for the fabrication of functional gradient materials for SOFC electrodes.