SOFC阴极材料(La_0.85Sr_0.15)(Mn_(1-y)Cr_y)O_(3+δ)的非化学整比、晶体结构、电导率和热膨胀性能

Nonstoichiometry, Crystal Structure, Conductivity and Thermal Expansion Property of (La0.85Sr0.15)(Mn1-yCry)O3+δ for SOFC

研究了掺杂Ｃｒ２Ｏ３对（Ｌａ０．８５Ｓｒ０．１５）ＭｎＯ３（以Ｃｒ部分取代Ｍｎ）Ｍｎ４＋离子的含量、氧非化学整比、晶体结构、电导率和热膨胀系数的影响。结果表明，随Ｃｒ取代Ｍｎ的摩尔比ｙ增加［Ｍｎ４＋］／［Ｍｎ＋Ｃｒ］比率和氧的非化学整比δ减小，而［Ｍｎ４＋］／［Ｍｎ３＋］比率不变；ＬＳＭＣ的晶体结构仍属菱形六面体，且结构和成分（δ）从室温到１０００℃保持稳定；ＬＳＭＣ的导电激活能增大，但在１０００℃时电导率趋于相同。

As cathode materials (La0.85Sr0.15)-(Mn1-yCry)O3+δ with y=0,0.05,0.1,0.15 and 0.2 for SOFC were synthesized by powder sintering in air. Nonstoichiometry, crystal structure, electrical conductivity and thermal expansion coefficient of the compounds were investigated. With increasing y, it was shown among all samples that the molar ratio [Mn4+]/ and oxide nonstoichiometry δ decreased but the molar ratio [Mn4+]/[Mn3+] was constant, and that the conductivity tended to close to 1000℃, although the conductive activation energy Ea increased. The crystal structure was rhombohedral, and the thermal expansion coefficient was always compatible between the cathode materials and YSZ.