Synthesis, characterization, fabrication, and electrochemical performance of transition metal doped LSCTA- as anode candidates for SOFCS

In this work, lanthanum calcium strontium titanates (La0.2Sr0.25Ca0.45TiO3; LSCTA-) are modified with zinc, manganese and chromium (1%; 5%) for their application as solid oxide fuel cell anodes. These compositions are characterized by X-ray diffraction that indicate successful doping of metals onto the parent (LSCTA-) material without a change in the crystallography and leading to a lattice contraction depending on metal element and amount. Fabrication of the electrodes from the LSCTA- on yttria-stabilized zirconia plates is done by air spraying. The electrode performance of the materials is checked under reducing atmosphere (dry; 5% H2/Ar, humidified; 4% H2O/H2) and at different sintering (1200 and 1250°C) and operating (750–650°C) temperatures. The materials sintered at high temperature (1250°C) show comparatively lower polarization resistances (RP) under humidified atmosphere, hence indicate better electrode performance in the presence of steam. Among these doped compositions, polarization resistance is found lower for LSCTA-modified with 1% Zn than all other doped compositions. Overall, the polarization resistance of both LSCTA-with 1% Zn (23 Ωcm2) and 5% Zn (25 Ωcm2) at 750°Cis found lower in comparison to the value reported at 900°C for parent material (45Ωcm2) under humidified atmosphere.