Preparation and Conductivity Studies of La9.33Si6O26 (LSO) -Ce0.85Gd0.15O1.925 (CGO15) Composite Based Electrolyte for IT-SOFC

Reducing a high-operating temperature of solid oxide fuel cell (SOFC) to intermediate temperature SOFC (IT-SOFC, 500-750ºC) poses a great challenge in the sense of developing solid electrolyte at intermediate temperature range. In response to this, we report a novel composite La9.33Si6O26 (LSO) - Ce0.85Gd0.15O1.925 (CGO) in this study. The synthesis of LSO-CGO composite was carried out by combining LSO with CGO (9:1, 8:2, and 7:3 in weight ratio) using solid state reaction method. In order to get a dense pellet, all of the products were sintered at 1500°C for 3 h. The X-ray diffraction pattern of sintered pellets show typical patterns for both of LSO and CGO which indicate that the composite was successfully formed. The highest conductivity was detected in 7LSO-3CGO, i.e. 2.10×10-3 S cm-1 at 700 ○C and also has low activation energy (0.60 eV). This result suggests that the LSO-YSZ composites are good oxide ion conductors and may potentially be used as an alternative solid electrolyte in IT-SOFC technology.