Sm0.2 Ce0.8 O1.90 (SDC)/ Y0.25 Bi0.75 O1.5 (YSB) Bilayered Electrolytes for Intermediate Solid Oxide Fuel Cells

Bilayered electrolytes samarium doped ceria (SDC)/yttria stabilised bismuth (YSB) were investigated to develop intermediate temperature of solid oxide fuel cells (IT-SOFCs). The aim of this study was to investigate the effects of the calcination on the microstructure of SDC/YSB bilayered electrolytes in IT-SOFC. Bilayered electrolytes SDC and YSB were syntesised via sol-gel and a solid state reaction method. The SDC powders were calcined at 800, 1000 and 1200°C for 5 h whereas YSB powders were calcined at 550, 650 and 750°C for 2 h. The result from XRD showed that the SDC powder having a Sm0.2Ce0.8O1.9 structure after the calcine at a temperature of 800 to 1200°C for 5 h and YSB having an Y0.25Bi0.75O1.5 structure at 750°C for 2 h. An increase in the calcination temperature on the SDC at 800, 1000 and 1200°C for 5 h caused an increased in crystalline size to 42.4, 58.7 and 79.9 nm, respectively. An increase in YSB calcination temperature to 750°C resulted in the transformation of YSB from tetragonal into cubic fluorite structure with a crystallite size of 28.86 nm. By comparing the results of cell performance test in intermediate operation temperature (650°C), bilayered electrolytes (SDC/YSB) with the calcination temperature SDC-1200°C and YSB-750°C showed the highest cell performance with power density 81.55 mW /cm² and current density of 225.36 mA/cm².