Novel SrTi_xCo_1-xO_3-δ cathodes for low-temperature solid oxide fuel cells

The SrTi_xCo_1-xO_3-δ (STC, x = 0.05, 0.1, 0.15, 0.2) perovskite-type oxides synthesized by the polymerized complex (PC) method have been investigated as cathode materials for low-temperature solid oxide fuel cells (SOFCs) with composite electrolyte for the first time. Thermogravimetry-differential thermal analysis (TG-DTA) shows the crystallization of SrTi_0.1Co_0.9O_3-δ occurs at 780 °C. The oxides have been stabilized to be a cubic perovskite phase after the B-site is doped with Ti ion. The maximum power density reaches as high as 613 mW cm^-2 at 600 °C for SOFC with SrTi _0.2Co_0.8O_3-δ cathode. The maximum power densities increase with the increasing Ti content in the cathode, which can be attributed to the enhancement of conductivity and electrocatalytic activity. The stability of the fuel cell with SrTi_0.1Co_0.9O _3-δ cathode has been examined for 18 h at 600 °C. Only a slight decline in the cell performance can be observed with increasing time. The high performance cathodes together with the low-cost fabrication technology are highly encouraging for development of low-temperature SOFCs.