Effect of Al2O3 film on thermal stress in the bonded compliant seal design of planar solid oxide fuel cell

This paper uses finite element method to study the effect of Al2O3 film on thermal stresses in the bonded compliant seal (BCS) design of a planar solid oxide fuel cell. The effects of Al2O3 thickness, operating temperature, window frame thickness, foil thickness and cell length on thermal stresses have been discussed. The results show that compressive stresses are generated in Al2O3 film. A bowing deformation is generated due to the BCS design, which can trap and relax some thermal stresses. With Al2O3 thickness increase, compressive stresses in Al2O3 film and foil are decreased slightly, while tensile stresses in BNi2 and frame are increased. With operating temperature increase, compressive stress in Al2O3 is increased greatly, while the stresses in foil, BNi2 and frame are increased slightly. The bowing deformation is increased with operating temperature increase. The window frame thickness has little effect on thermal stresses and bowing deformation. With sealing foil thickness increase, thermal stresses and bowing deformation are increased. The cell length has little effect on thermal stresses, but reducing the cell length can decrease the bowing deformation.

► Large compressive stresses are generated in Al2O3 film.
► A bowing deformation is generated due to the S-shaped bonded compliant seal design.
► The bowing deformation is decreased with Al2O3 thickness increase.
► With foil thickness increase, thermal stresses and bowing deformation are increased.
► Reducing the cell length can decrease the bowing deformation.