Synthesis and Characterization of ( La0.75Sr0.25 ) Cr0.5Mn0.5 O 3 − δ , a Redox-Stable, Efficient Perovskite Anode for SOFCs
Synthesis and Characterization of ( La0.75Sr0.25 ) Cr0.5Mn0.5 O 3 − δ , a Redox-Stable, Efficient Perovskite Anode for SOFCs
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DOI：
10.1149/1.1639161
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发表时间：
2004-02
影响因子：
3.9
通讯作者：
S. Tao;J. Irvine
中科院分区：
文献类型：
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作者：
S. Tao;J. Irvine
钙钛矿相关材料（La 0.75 Sr 0.25） 1-x Cr 0.5 Mn 0.5 O 3-δ(0≤x≤0.1)（LSCM）已被合成并作为固体氧化物燃料电池（SOFCs）的潜在负极材料进行了研究。La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 o3呈菱形结构。它似乎与钇稳定的氧化锆（YSZ）在至少1300°C下化学相容。在900°C时，其电导率在空气中约为38 S/cm，在5% h2 （p O, 10 -21 atm）中约为1.5 S/cm。采用LSCM作为阳极，在5% h2 /Ar和湿h2中极化电阻分别为0.9和0.47 Ω cm 2，具有良好的性能。当在YSZ和LSCM阳极之间涂覆ce0.8 Gd 0.2 O 2-δ (CGO)薄层时，在5% h2 /Ar和湿h2条件下，阳极极化进一步降低到0.6和0.25 Ω cm 2。在湿甲烷中运行至少可保持4小时的稳定性能。通过改善电极微观结构，含有少量YSZ但不含CGO的LSCM在97% h2 /3% h2o条件下，在900℃时电极极化电阻接近0.2 Ω cm 2。在不使用多余蒸汽的情况下，对甲烷取得了很好的性能。使用环境加湿（即3% h2o），在950°C下，甲烷和850°C下的氢气可以达到相同的性能。该阳极在燃料和空气条件下都是稳定的，在甲烷中表现出稳定的电极性能。因此，低蒸汽碳氢化合物的氧化还原稳定性和可操作性都得到了证明，克服了当前一代镍锆金属陶瓷SOFC阳极的两个主要限制。LSCM和其他复合钙钛矿是很有前途的sofc负极材料。
Perovskite-related materials, (La 0.75 Sr 0.25 ) 1-x Cr 0.5 Mn 0.5 O 3-δ (0 ≤ x ≤ 0.1) (LSCM), have been synthesised and examined as potential anode materials for solid oxide fuel cells (SOFCs). La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 exhibits a rhombohedral structure. It appears to be chemically compatible with yttria-stabilized zirconia (YSZ) to at least 1300°C. At 900°C, its electrical conductivity is about 38 S/cm in air and 1.5 S/cm in 5% H 2 (p O , 10 -21 atm). Good performance was achieved using LSCM as anode with a polarization resistance 0.9 and 0.47 Ω cm 2 in wet 5% H 2 /Ar and wet H 2 , respectively. The anode polarization was further reduced to 0.6 and 0.25 Ω cm 2 in wet 5% H 2 /Ar and wet H 2 when a thin layer of Ce 0.8 Gd 0.2 O 2-δ (CGO) layer was coated between YSZ and LSCM anode. Stable performance was sustained for at least for 4 h operating in wet methane. By improving the electrode microstructure the electrode polarization resistance approaches 0.2 Ω cm 2 at 900°C in 97% H 2 /3% H 2 O for LSCM containing a small amount of YSZ to improve adherence but without CGO. Very good performance is achieved for methane without using excess steam. Using ambient humidification (i.e., 3% H 2 O), the same performance is achieved with methane at 950°C as for hydrogen at 850°C. The anode is stable in both fuel and air conditions and shows stable electrode performance in methane. Thus, both redox stability and operation in low-steam hydrocarbons have been demonstrated, overcoming two of the major limitations of the current generation of nickel zirconia cermet SOFC anodes. LSCM and other complex perovskites are promising anode materials for SOFCs.