Effect of YSZ addition on the performance of glass-ceramic seals for intermediate temperature solid oxide fuel cell application

The suitability of glass-based seal is evaluated for application in intermediate temperature solid oxide fuel cell (SOFC). Several glass-YSZ composite seals are investigated in temperature range from 650 °C to 800 °C. The leakage rates are obviously reduced with temperature increased. The seal containing 20 wt% YSZ exhibits excellent gas tightness and thermal cycle stability, obtaining the leakage rate of 0.005 sccm cm−1 under input gas pressure of 6.8 kPa at 750 °C. Stable leakage rates can be maintained after ten thermal cycles, implying that YSZ addition suppresses crack propagation of the seals. It is also explained by both interfacial bondage and chemical compatibility examination. When large-area-cell is operated during five thermal cycling tests, its performance is found to be constant at 750 °C, all of cell tests achieving OCV of 1.2V and power density of 520 mW/cm2. The above results demonstrate the possibility of using the H1-20 seals for SOFC application.