The precursors of La<,0.7>Sr<,0.3-x>Ca<,x>Co<,0.9>Fe <,0.1>O<,3-δ> (LSCCF, x=0.05, 0.10, 0.15, 0.20) as the cathode materials for intermediate temperature solid oxide fuel cell (ITSOFC) were prepared by reverse titration co-precipitation method with metal-nitrates as starting materials and mixed alkali (NaOH and Na<,2>CO<,3>) as a precipitating agent. The formation process of LSCCF from the precursors was monitored by TG-DSC, and the crystal structure and particles morphology of the precursors which were calcined at 600, 800, 1000℃ for 3h were characterized using XRD, SEM technologies. Compared with the solid state reaction of constituent oxides, when the pH value of the precipitating solution was in the range of 9.1~9.5, the LSCCF powders from the precursors caclined at 800℃ for 3h had high purity, homogeneous and single perovskite phase. The electrical conductivity of the LSCCF samples sintered at 1200℃ for 3h, which was measured as a function of temperatures from 100 to 800℃ by DC four-probe method in air, decreased with x from 0.05 to 0.20. The value of electrical conductivity was almost equal because of Ca<2+>, Sr<2+> co-dopant resulting in the mix effect while x= 0.10 or 0.15. The electrical conductivity of all doped samples was higher than 100S·cm<-1> at intermediate temperatures from 500 to 800℃, and there was good compatibility between the LSCCF cathode and Ce<,0.8>Sm<,0.2>O<,2> electrolyte.
Gao Wenyuan(高文元) Hu Zhiqiang(胡志强) Li Changmin(李长敏) Tang Nailing(唐乃岭) Sun Fulu(孙福禄) Tang Xu(唐旭) Wei Qiangwei(魏蔷薇) Sun Yongping(孙永平)
Department of Material Science and Engineering, School of Chemistry Engineering and Material, Dalian Department of Material Science and ngineering, School of Chemistry Engineering and Material, Dalian Department of Material Science and Engineering, School of Chemistry Engineering and Material, Dalian Department of Material Science and Engineering, School of Chemistry Engineering and Material, Dalia