Electro-Chemical-Thermal-Mechanical Numerical Simulation and Failure Analysis for the Double Side Cathode Solid Oxide Fuel Cell Stack Units with Different Collecting Positions

In this work, a three-dimensional numerical model for the double side cathode solid oxide fuel cell (DSC-SOFC) is established by the finite element method based on the electro-chemo-thermal-mechanical multi-physics coupling theory. Using this model, the thermal stress distribution and optimization on the current collection scheme of the developed DSC-SOFC are investigated. In this study, the thermodynamic model is combined with the Weibull failure probability theory to study the influence of the collecting position on the thermal stresses and the failure of the DSC-SOFC. The results show that the average current density of the double side current collection is higher than that of the single side current collection, and different positions of the anode current collections result in the different distributions of the electrode temperature. Furthermore, the maximum principal stress at the electrode structure of the SOFC is significantly higher than those on other components. When the anode current collection position is set at the anode gas inlet, the maximum principal stress and the failure probability are larger than the case when the anode current collection position is at the anode gas outlet.