Abstract: 　Double perovskite oxide Sr1.85MgMoO6-δ was synthesized by sol⁃gel method in 5% H2/Ar, and its structural stability was characterized by XRD. The experimental results show that the structure and phase composition of Sr1.85MgMoO6-δ have not changed after high temperature oxidation treatment, which fully proves its structural stability. The conductivity, thermogravimetric and electrochemical impedance spectra of Sr1.85MgMoO6-δ and Sr2MgMoO6-δ were measured in the same environment. The experimental results show that Sr vacancy can effectively enhance the conductivity of the material itself and increase the oxygen vacancy of the material. In addition, the polarization impedance value Sr1.85MgMoO6-δ (2.26~0.56 Ω·cm2) in H2 is smaller than that in Sr2MgMoO6-δ (4.80~1.96 Ω·cm2) at 700~800 oC temperature. Therefore, Sr1.85MgMoO6-δ double perovskite material is a very promising medium temperature solid oxide fuel cell (SOFC) anode material.

Key words: Solid oxide fuel cell, Double perovskite, Anode, Electrical conductivity, Polarization impedance

摘要： 通过溶胶凝胶法在H2（体积分数5%）/Ar气氛中合成双钙钛矿氧化物Sr1.85MgMoO6-δ，采用XRD对其进行了结构稳定性表征。结果表明，Sr1.85MgMoO6-δ经高温氧化处理，其结构与相成分未发生明显变化，充分证明其良好的结构稳定性。电导率和热重结果表明，引入Sr缺位可有效提高材料在H2下的电子电导率，并增大晶格中氧空位浓度，有利于电子和氧离子在阳极区的快速输运。电化学阻抗谱测试发现，温度为700~800 ℃时，Sr1.85MgMoO6-δ 阳极在H2中的极化阻抗(2.26~0.56 Ω·cm2)要远小于Sr2MgMoO6-δ阳极的极化阻抗(4.80~1.96 Ω·cm2)，这主要是由于Sr缺位提高了阳极的离子和电子输运能力的原因。研究结果表明，Sr1.85MgMoO6-δ双钙钛矿材料是一种非常有潜力的中温固体氧化物燃料电池（SOFC）阳极材料。

关键词: 固体氧化物燃料电池, 双钙钛矿, 阳极, 电导率, 极化阻抗