ITSOFC阴极材料Ln-B-Co-O的合成与性能

Synthesis and performance of Ln-B-Co-O as cathode material for ITSOFC

以混合稀土、SrCO3、CaCO3及Co2O3为原料，在1200℃下烧结制备了Ln-B-Co-O（Ln为混合稀土，B=Sr，Ca）复合氧化物，并采用TG-DSC、XRD和直流四探针等方法进行了分析。混合稀土促进了碳酸盐在700～900℃的分解，新相Ln0．7Sr0．3 C003-δ在1100℃时基本形成。Ln—B-Co-O复合氧化物为Ce02立方萤石相与钙钛矿两相，Sr^2＋易与稀土中的Ce02反应形成钙钛矿，Ca^2＋易与La^3＋发生取代。Ln-Ca-Co-O的电导率大于Ln-Sr-Co-O，在1200℃下烧结3h的所有样品的电导率，在340℃时达到最大值，在500～800℃时均超过500S／cm。

Sintered at 1 200 ℃ with mischmetal, SrCO3, CaCO3 and Co203 as raw materials, Ln-B-Co-O （Ln = mischmetal, B = Sr or Ca） composite oxides were synthesized and investigated by TG-DSC, XRD and Four-probe DC methods. The mischmetal enhanced the decomposition of carbonate at 700 - 900 ℃ the new phase Ln0.7Sr0.3CoO3-δ basically formed at 1 100 ℃, Ln-B- Co-O composite oxides had two phase with CeO2 cubic fluorite and perovskite, Sr^2＋ united with the CeO2 of rare earth easily and became perovskite, Ca^2 ＋ substituted La^3 ＋ easily. The conductivity of Ln-Ca-Co-O was higher than Ln-Sr-Co-O. The conductivity of all samples sintered at 1 200 ℃ for 3 h increased to maximum at 340 ℃ and was higher than 500 S/cm at 500 - 800℃.