Development of co-sintering process for anode-supported solid oxide fuel cells with gadolinia-doped ceria/lanthanum silicate bi-layer electrolyte. (30th August 2019) - Takahashi, Susumu
Abstract: Gadolinia-doped ceria (GDC) and lanthanum silicate (LS) are expected to be promising materials for electrolytes of solid oxide fuel cells (SOFCs) because of their high ionic conductivities at intermediate temperatures. However, performance degradation of SOFCs is caused by current leakage through GDC and poor densification of LS. In the present study, LS was used as a blocking layer for preventing the current leakage of GDC electrolyte. Thermal shrinkage measurements and scanning electron microscopy (SEM) observation suggested that the addition of Bi2 O3 in LS electrolyte (LSB) contributed to the decrease in the sintering temperature of the LS and improved densification of the GDC/LS bi-layer electrolyte. Consequently, the open-circuit voltage for the cell with GDC/LS and GDC/LSB bi-layer electrolytes increased effectively in comparison with that of the cell with GDC single-layer electrolyte. The electrical conductivity and fuel cell characteristics were compared among the cells with GDC, GDC/LS, and GDC/LSB electrolytes. Graphical abstract: Image 1 Highlights: SOFCs with (Ce, Gd)O2 (GDC)/La9.333 Si6 O26 (LS) bi-layer electrolytes were developed. Addition of Bi2 O3 in LS effectively contributed to the co-sintering of the micro-tubes. Utilizations of GDC/LS and GDC/LSB bi-layer electrolytes improved OCV for SOFCs. Power density of the SOFC with the GDC/LS bi-layer electrolyte was enhanced.