阴极材料Ln-Sr(orCa)-Cu-O的制备及电性能

Preparation of Ln-Sr(or Ca)-Cu-O cathode materials and its electrical properties

为了降低原料成本和适于工业化生产，以混合稀土取代氧化镧经硝酸溶解后，共沉淀法分别制备了Sr、Ca掺杂阴极材料LnSr（or Ca）-Cu—O（Ln为混合稀土）的前驱体，在优化条件800℃下煅烧3．5h形成了粉体，XRD证实形成的物相为CeO2立方萤石相与钙钛矿相。当2θ在20°～30°变化时，Sr^2＋掺杂使Ln—Sr0.5CuO3-δ形成的钙钛矿结构衍射峰相对完整；当2θ在30°～45°变化时，Ca^2＋掺杂却使Ln0.5Ca0.5CuO3-δ钙钛矿结构衍射峰发生扭曲；而2θ在50°～60°时，Ln0.5Ca0.5CuO3-δ和Ln0.5Sr0.5CuO3-δ衍射峰发生了不同程度的偏移和裂变。直流四探针法对合成产物烧结样品的电导率测量结果表明，在相同条件下，Ln0.5Sr0.5CuO3-δ电导率大于Ln0.5Ca0.5CuO3-δ电导率，在420℃时电导率达到最大值，分别为574和559S／cm。在中温固体氧化物燃料电池工作温度500～800℃，阴极材料电导率超过500S／cm，满足电池阴极材料电性能的要求。

In order to reduce the cost of raw materials the Ln-Sr（or Ca）-Cu-O （Ln is mixed rare cathode materials precursors were prepared by the co-precipitation method after dissolved the rare earth with nitric acid. The produced powder calcined at 800 ℃ for 3.5 h showed both earth） mixed cubic fluorite and perovskite phase. The diffraction peak of perovskite structure generated from Ln0.5Sr0.5CuO3-δ was relatively complete at 2θ angle ranged in 20°-30°. The diffraction peak of perovskite structure generated from Ln0.5Ca0.5CuO3-δ was distorted at 28 angle ranged in 30°-45°. The diffraction peaks of both Ln0.5Ca0.5CuO3-δ and Ln0.5Sr0.5CuO3-δ were shifted and split to some extent at 2θ angle in 50°-60°. The electrical conductivity of Ln0.5Sr0.5CuO3-δ is higher than that of Ln0.5Ca0.5CuO3-δ and has the highest electrical conductivity at 420 ℃. The electrical conductivity is higher than 500 S/cm at its working temperature 500 to 800 ℃ of intermediate temperature solid oxide fuel cell（ITSOFC）, which could meet the requirements of electrical properties of cathode materials.