Evaluation of stability and functionality of BaCe1−xInxO3−δ electrolyte in a wider range of indium concentration

The properties of BaCe1−xInxO3−δ (x = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, and 0.40) as proton conducting electrolyte are examined. The dense electrolyte is formed after sintering at 1300 °C for 5 h in air. The samples with In content ⩾ 25 mol% contain In2O3 as a secondary phase. The highest total conductivity is around 5×10−3 S/cm for BaCe0.75In0.25O3−δ in the wet hydrogen atmosphere at 700 °C. After exposure to pure CO2 atmosphere at 700 °C for 5 h, the concentrations of at least 15 mol% In can completely suppress degradation of the electrolyte. The power density of Ni-BaCe0.75In0.25O3−δ/BaCe0.75In0.25O3−δ/LSCF-BaCe0.75In0.25O3−δ fuel cell tested in wet hydrogen atmosphere reaches 264 mW/cm2 at 700 °C. This result is an indication of stability and functionality of this electrolyte and its versatility in respect to type of fuel and performing environment.