(La,Sr)(Co,Fe)O_3与(La,Sr)MnO_3阴极材料的表征与性能

采用氨水沉淀法分别制备La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)与La0.8Sr0.2MnO3-δ(LSM)两种阴极材料,并用X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)和比表面积(BET)对所制备材料的结构、晶粒大小、形貌及比表面积进行表征.结果表明,LSCF和LSM前驱体分别在900℃和1200℃煅烧5h后产物均形成单一正交的钙钛矿结构,但LSCF具有较小的粒径和较大的比表面积.电化学性能测试结果表明,LSCF阴极比LSM阴极的过电位低,且LSCF为阴极单电池的输出功率较高.

Properties of (La,Sr) (Co,Fe) O_3 and (La,Sr) MnO_3 Cathode Materials

La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ) (LSCF) and La_(0.8)Sr_(0.2)MnO_(3-δ) (LSM) cathode materials were prepared by co-precipitation method in the OH- solution. The properties of LSCF and LSM powders were characterized by XRD,BET and FESEM. The results show that LSCF and LSM precursors can be transformed to the pure orthorhombic perovskite structure having been calcined at 900 ℃ and 1 200 ℃ for 5 h,respectively,and LSCF cathode has a smaller particle size and a bigger specific surface area compared with LSM cathode. The investigation of electrochemical properties show that LSCF cathode has lower over-potential compared with LSM cathode,which reveals that the electrode activity of LSCF cathode is better than that of LSM cathode. The V-I characteristics of single cell show that the cell with LSCF cathode has a better performance than LSM cathode.