Abstract: This paper reports the use of Au films to improve the performance of the stacked solid oxide fuel cell (SOFC) based on the characterization of the interface and the adhesion between the electrodes of the SOFCs and the Ag paste. The specimens were manufactured to perform the experiment as follows. A SiO₂ wafer with a 300 μm notch was attached to the electrodes of a SOFC by a Ag paste and Au film, which were deposited on the electrodes by sputtering for 1 min or 5 min deposition time and annealed at 300 °C for 1 h. The four-point bending test was performed, which resulted in the formation of an extended crack at the tip on the wafer notch, and the crack propagation was observed using a stereo microscope equipped with a charge-coupled device (CCD). Consequently, the interfacial adhesion energy and the effect of the Au film between the each electrode and the Ag paste can be evaluated. On the cathode, the interfacial adhesion energy without Au film was 2.59 J/m² (upper value) and the adhesion energy increased to 11.59 J/m² (upper value) and 15.89 J/m² (lower value) with the Au film. On the anode, the interfacial adhesion energy without Au film was 1.74 J/m² (upper value), which increased to 11.07 J/m² (upper value) and 14.74 J/m² (lower value) with the Au film. In addition, the interface areas were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) to estimate the interface delamination.

Key words: Solid oxide fuel cell, Au film, Interfacial adhesion energy