LaCrO3基固体氧化物燃料电池(SOFC)连接材料存在难以在空气中致密化烧结、中温电导率差等缺陷。本文利用自燃烧工艺(auto-ignition process)制备La0.7Ca0.3CrO3-δ高活性粉体,掺入2%~8%(质量分数)CeO2作为烧结助剂,在1 400℃空气气氛下烧结获得了95.4%以上的高致密度,并且随着CeO2掺杂量的增加晶粒逐渐细化;掺入2%CeO2时La0.7Ca0.3CrO3-δ烧结样品的电导率最高,在空气中850℃达到52.7Scm-1,500℃时也能达到41.9Scm-1,约为同等条件下未掺杂La0.7Ca0.3CrO3-δ电导率的2.5倍,完全能够满足中温固体氧化物燃料电池连接材料的使用要求。
LaCrO3-based interconnect material for solid oxide fuel cells(SOFCs) is poorly sinterable in air and has relatively low electrical conductivity at intermediate temperatures.In this work,fine precursor powders of La0.7Ca0.3CrO3-δ were prepared by introducing an auto-ignition process,and then sintering in air at 1 400℃ for 4h using a small amount of CeO2 as sintering aid(2%-8%,weight percent).Results indicate that the doped specimens sintered at 1 400℃ for 4h in air have high relative densities of no less than 95.4% and the grain size decreases with increasing the doping amount.The 2% CeO2-doped La0.7Ca0.3CrO3-δ sample has the highest electrical conductivity of 52.7 Scm-1 at 850℃ and 41.9Scm-1 at 500℃ in air,almost 2.5 times as high as that of La0.7Ca0.3CrO3-δ.Results indicate this interconnect composite is very suitable for intermediate temperature SOFCs.