Thermal stress and deformation in bonded compliant seal design for planar SOFC

In this paper, a bonded compliant seal(BCS) is designed for planar solid oxide fuel cell(SOFC).Its thermal stress and deformation are analyzed by finite element method.In addition, the thermal stress generated in the conventional glass-ceramic sealing method is also calculated to compare with BCS method, through which the advantages of BCS design are verified based on the consideration of thermal stresses.It is shown that the thermal stress in BCS design is reduced by 167 MPa compared with the glass-ceramic sealing.In BCS design, a thin foil metal is used to bond the cell and the window frame.During the cooling process, a bowing deformation is generated, which makes SOFC deform flexibly.The thermal stress in SOFC stack can be mitigated by trapping much of it as elastic or plastic strain within the sealing foil, which leads to a decrease of thermal stress in the SOFC stack.The maximum thermal stress in BCS design locates at the fillet of filler metal which becomes the weakest area.