Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)阴极材料的制备与性能

Synthesis and properties of Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) cathode materials

氢氧根共沉淀法合成了阴极材料Ba0．5Sr0．5Co0．8Fe0．2O3-δ（BSCF）。利用XRD、SEM、EDX和DSC／TG等技术研究了前驱体不同温度煅烧后的晶化行为，考察了BSCF材料的电导率和热稳定性能。结果表明，前驱体在1173K下煅烧2h，产物为单一的立方型钙钛矿相结构，粒径在1mm以下；当煅烧温度升至1273K，产物的组成配比为Ba0．48Sr0．52Co0．78Fe0．19O3-δ，但粉末之间发生烧结。空气中，BSCF支撑体的电导率在773-1073K之间均在120S／cm以上。材料在1183K时发生相转变，相变焓为49．47J／g，但材料在673-1273K仍显示了较好的热稳定性。

Ba0.5Sr0.5Co0.8Fe0.2O3-δ （BSCF）, the new cathode material of solid oxide fuel cell （SOFC）, was synthesized by co-precipitation method used by OH^- solution. The effects of calcination temperature on the phase structure and surface morphology of precursors were investigated by XRD, SEM and EDX, the results show that the precursors can be transformed to the pure cubic perovskite structure after calcined at 1173K for 2h,and the particles size of powders is less than lmm. When calcination temperature is 1273K, the powders possess exact component （Ba0.48Sr0.52Co0.78 Fe0.19 O3-δ）, but powders are sintered. It shows that the electrical conductivity of the sample is higher than 120S/cm during 773- 1073K. The changes in mass and heat of powders as a function of temperature have been determined by DSC and TG. It is found that the phase structure of BSCF has been transformed at 1187K in the air,and the enthalpy change of the reaction is 49.47J/g. BSCF possesses a perfect thermal stability during 673-1273K.