锰酸锶镧基阴极的制备及结构参数的优化

Optimization of Processing and Structural Parameters of Lanthanum Strontium Manganate-based Cathodes

采用固相法合成了具有A位空位的锰酸锶镧(Lanthanum Strontium Manganate,LSM)基阴极材料(La_(0.8)Sr_(0.2))_(0.9)MnO_(3−δ),并研究了锰酸锶镧-氧化钇稳定的氧化锆(Lanthanum Strontium Manganate-Yttria-Stabilized Zirconia,LSM-YSZ)复合阴极的缺陷结构、LSM和YSZ的成分比例、孔结构特性和电荷收集方式等重要参数对阳极支撑固体氧化物燃料电池(Solid Oxide Fuel Cell,SOFC)性能的影响。研究发现:与化学计量的LSM相比,具有10%A位空位的LSM具有更好的阴极活性;采用聚乙烯醇缩丁醛(Polyvinyl Butyral,PVB)作为阴极浆料黏结剂有助于形成连通的孔道;LSM-YSZ复合阴极LSM与YSZ的最佳质量比为6:4,其优选的孔隙率为28%;在LSM-YSZ复合阴极外增设具有良好孔隙结构的LSM电荷收集层能有效地提升阴极性能,其优选的孔隙率为42%。采用上述优选的阴极工艺参数制备的阳极支撑SOFC单电池在800℃的最大功率密度为780 mW·cm^(−2)。

Lanthanum strontium manganate(LSM)-based cathodes,(La_(0.8)Sr_(0.2))_(0.9)MnO_(3−δ)with A-site deficiency,were prepared by the conventional solid-state reaction.The effects of several factors,including defect structure,mass ratio of LSM and YSZ,pore structure characteristics and charge collection methods of the lanthanum strontium manganate-yttria-stabilized zirconia(LSM-YSZ)composite electrode,on performance of the anode-supported solid oxide fuel cells(SOFCs),were studied.It was found that the LSM with 10%A-site deficiency has higher performance than the stoichiometric LSM.The cathode slurry with polyvinyl butyral(PVB)as the binder has better pore structure.The optimal weight ratio of LSM to YSZ is 6:4,with optimized porosity of 28%.The cathode performance could be effectively improved by coating an LSM current collection layer on the LSM-YSZ layer,while the optimized porosity of the LSM current collection layer is 42%.Under the optimal conditions,a peak power density of 780 mW·cm^(−2) was achieved at 800℃.