LaScO3-based electrolyte for protonic ceramic fuel cells: Influence of sintering additives on the transport properties and electrochemical performance

In this work, the effect of the content of CuO, ZnO, Al2O3, NiO, Fe2O3, Co3O4 and MoO3 additives on the sinterability, microstructure, and electrical properties of La0.9Sr0.1ScO3-alpha, proton-conducting oxide in a form of tubes produced by slip casting is studied. It is shown that the relative density of La0.9Sr0.1ScO3-alpha, tubes without sintering aids is similar to 86%. The introduction of 1.0 wt % ZnO, Al2O3, NiO or 0.5 divided by 1.0 wt % Co3O4 leads to a relative density of ceramics higher than 95%. Among dense ceramic tubes, LSS +0.5 wt % Co3O4 has the highest electrical conductivity. The introduction of 1 wt % Fe2O3 additive does not affect the sinterability of the LSS, and 1 wt % CuO and MoO3 inhibits LSS sintering. Single protonic ceramic fuel cells based on LSS +0.5 wt % Co3O4 and LSS +1.0 wt % NiO supporting electrolyte tubes with a thickness of 300 mu m are studied. The maximum power density of about 30 mW/cm(2) at 800 degrees C was obtained for a cell based on LSS +0.5 wt % Co3O4 using wet hydrogen as fuel and air as an oxidizing gas.