Residual Stress and Thermal Stress in Ni/YSZ Anode Support Micro-Tubular Solid Oxide Fuel Cell

Abstract

The most commonly used Micro tubular solid oxide fuel cell (MT-SOFC) anode material is a two phase nickel and yttria stabilized zirconia (Ni/YSZ) cermet. And the mechanical stability of anode support layer, in anode-supported electrolyte designs, is very important for large scale applications. During the assembly of stack and normal operation, MT-SOFC is easy to crack under the residual stress induced by manufacture and thermal stress due to multi-physics coupling. In this work, MT-SOFC model was founded on the background of MT-SOFC stack of electric vehicle and was analyzed by finite element method, based on theories of multi-physical field coupling. In order to find out which is the main reason for cracking, the residual stress due to manufacture and work were investigated separately. Thermal stress based on residual stresses of operating are studied for further research of life of MT-SOFC. It concluded that the failure of the MT-SOFC occurs mainly because of the residual stress due to the mismatch between the coefficients of thermal expansion of the materials of the electrode assembly, thermal stress will increase the mismatch in some partial areas. The results are important for studying the life and final spallation of MT-SOFC of electric vehicle.