An Analytical Model for Investigations on the Stress Distribution in Planar Solid Oxide Fuel Cells

Abstract

An analytical model is presented to determine the residual stress distribution in planar Solid Oxide Fuel Cells (SOFCs). Usually, the residual stress in SOFCs is generated due to deposition processes of several layers in the manufacturing route and the CTE mismatch due to cooling from deposition to ambient temperature. In this model the deposition as well as the thermal stress are considered in each layer. The final residual stress is obtained by adding the contributions of deposition and thermal stress. The investigated SOFC is an MSC type. After anode deposition, the total stress is in the tensile range. The electrolyte deposition results in large compressive stresses in the electrolyte but still tensile stress remains in the anode layer. This leads to the conclusion that thermal stress due to CTE mismatch has minor influence on the residual stress in contrast to the deposition stress. These observations hold for several parameter sets.