Study on sealing planar SOFC

A novel composite brazing of Ag-8CuO+2YSZ was used in air to seal anode-supported planar solid oxide fuel cell (SOFC) so as to prevent leakage. The effects of YSZ （(Y2O3)008(ZrO2)092） addition on the microstructure of Ag-CuO solders joint were investigated, and the open-circuit potential (OCP) of a single cell as a function of thermal cycle number was tested to value the sealing effect. SEM microstructures of joints show that the interface between YSZ particulates and Ag-CuO matrix is tight, and that the YSZ ceramic particles are evenly distributed in the brazing metal matrix, which is conducive to improving the brazed joints performance, reducing the CTE mismatch of the brazed joint, and inhibiting the formation of holes. The single cell sealed with the above sealing material could keep good open circuit voltage of 109~102 V when operating in 750 ℃ for 15 cycles, which shows that it is suitable for planar SOFC.