Performance evaluation of a new Fe-Cr-Mn alloy in the reducing atmosphere of solid oxide fuel cells
Performance evaluation of a new Fe-Cr-Mn alloy in the reducing atmosphere of solid oxide fuel cells
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新型Fe-Cr-Mn合金在固体氧化物燃料电池还原气氛中的性能评价
DOI：
10.1016/j.jallcom.2018.08.002
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发表时间：
2018
影响因子：
6.2
通讯作者：
Jian Li
中科院分区：
文献类型：
--
作者：
Wenying Zhang;Bin Hua;Jie Yang;Bo Chi;Jian Pu;Jian Li
一种新设计的Fe-Cr-Mn合金被认为是中温固体氧化物燃料电池（SOFC）互连材料的候选材料，在由N2+ 3.75vol%H2 + 25vol%H2O（g）组成的还原气氛中在650 °C、750 °C和850 °C下循环氧化，该还原气氛对应于SOFC阳极环境。结果表明，该合金在750 °C还原气氛下具有良好的抗氧化性和可接受的导电性。在1000 h的氧化过程中，在此温度下形成的氧化膜由内层掺Ti的Cr2 O3、中间层富Mn的Mn-Cr尖晶石和Mn 2 TiO 4以及顶层MnO组成，总厚度约为3 μm。在750 °C下的氧化动力学服从抛物线规律，从0到130 h的速率常数为1.37 × 10− 13 g2 cm − 4s − 1，从130到1000 h的速率常数为8.84 × 10− 14 g2 cm −4s− 1。在750 °C下测量的氧化皮的面积比电阻（ASR）为16.3 mΩ cm 2，其高于在氧化气氛中形成的面积比电阻，但仍在金属互连所需的100 mΩ cm 2的最大限度内。氧化温度从650 °C提高到850 °C，促进了Mn和Ti离子的向外扩散，从而改变了氧化物的组成和形貌;此外，合金的氧化速率急剧增加，导致氧化膜厚度和ASR值均增加。
A newly designed Fe-Cr-Mn alloy, considered as a candidate intermediate-temperature solid oxide fuel cell (SOFC) interconnect material, was cyclically oxidized at 650 °C, 750 °C, and 850 °C in a reducing atmosphere consisting of N2+3.75 vol% H2+25 vol% H2O(g) and corresponding to the SOFC anode environment. Results indicate that this alloy possesses good oxidation resistance and acceptable electrical conductivity at 750 °C in the reducing atmosphere. During the 1000 h oxidation, the oxide scale formed on the substrate at this temperature consists of an inner layer of Cr2O3doped with Ti, a Mn-rich middle layer of Mn-Cr spinel and Mn2TiO4, and a top layer of MnO, with an overall thickness of around 3 μm. The oxidation kinetics at 750 °C obey a parabolic law with rate constants of 1.37 × 10−13g2cm4s−1from 0 to 130 h, and of 8.84 × 10−14g2cm−4s−1from 130 to 1000 h. The area specific resistance (ASR) of the oxide scale measured at 750 °C is 16.3 mΩcm2, which is higher than that formed in the oxidizing atmosphere but is still within the maximum limit of 100 mΩcm2, required for metallic interconnects. The increase in oxidizing temperature from 650 °C to 850 °C promoted the outward diffusion of Mn and Ti ions, thus changing the composition and morphology of the formed oxides; in addition, the oxidation rate of the alloy increased dramatically, leading to an increase of both the oxide scale thickness and the ASR values.