阴极材料Ba0.5Sr0.5Co0.8Fe0.2O3-σ合成工艺优化

为了在较低温度下合成具有高纯度的阴极材料Ba0.5Sr0.5Co0.8Fe0.2O3-σ(BSCF),采用X射线、扫描电镜以及能谱分析等方法,研究了共沉淀合成法中溶液pH值和煅烧温度等工艺条件对产物的相结构、组成成分和颗粒形貌的影响.结果表明,pH值的升高使前驱体由草酸盐沉淀向氢氧化物沉淀转化,在pH=10条件下,前驱体1100℃煅烧2 h后形成了单一的立方型钙钛矿型结构,比在pH=6条件下的前驱体煅烧温度降低了约100℃,而且成分配比更为准确.研究认为前躯体溶液的pH值对煅烧产物的组成和形貌影响至关重要,这主要是由于pH值的不同改变了前驱体的组成和颗粒形貌造成的.

Optimization of the synthesis for the cathode material Ba0.5Sr0.5Co0.8Fe0.2O3-σ

As a new promising cathode material for intermediate temperature solid oxide fuel cell(ITSOFC),the pure Ba0.5Sr0.5Co0.8Fe0.2O3-σ(BSCF) was synthesized at low temperature by the optimization of co-precipitation.The dependences of the phase structure and the component of the BSCF powders on pH value and the calcination temperature were investigated by XRD,SEM and EDX.The results show that the pure cubic perovskite structure possessing the exact component is obtained after the precursors calcined at 1100 ℃ for 2 h when pH is 10.The calcination temperature is lowered about 100 ℃ compared with that pH is 6.It is concluded that pH value plays an important role in the component and morphology of products.It is mainly ascribed to the different components and morphologies of mother material at different pH values of the solution during the synthesis process.