摘要
固体氧化物电解池的金属连接板长期处于中高温环境(600~800℃)中,表面氧化严重使得电解池内阻增大,且金属基体的Cr挥发导致电极的电化学活性降低,二者共同作用导致电解池性能衰减严重。针对上述问题,采用电泳沉积法在商用SUS430金属基体上制备了Mn-Co涂层和Mn-Co-La涂层,再采用先后在中性气氛(950℃,N_(2))和氧化气氛(825℃,空气)条件下烧结的工艺,获得了牢固且致密的Mn-Co涂层和Mn-Co-La涂层。研究了烧结气氛和La元素掺杂对涂层性能的影响,分别利用扫描电子显微镜、X射线衍射仪、能谱仪、四探针电阻率测试仪测试了涂层的形貌、物相组成、元素分布、面比电阻。结果表明:通过电泳共沉积掺杂微量纳米La_(2)O_(3)制备的涂层的晶粒更加均匀、细化,有效抑制了高温N_(2)烧结过程中基体Fe-Cr的溢出。750℃下300 h的氧化循环试验结果表明,与基体相比,本工作提出的烧结工艺有利于提升涂层的抗氧化性能,且La掺杂的涂层性能更优。La元素的掺杂有效减缓了基体中的Cr挥发,面比电阻更低且稳定,提高了Mn-Co尖晶石涂层的抗高温氧化性能。
When metal connecting board of solid oxide electrolysis cell(SOEC)are used for long time in a medium-to-high temperature environment(600~800℃),severe surface oxidation increases the internal resistance of the electrolytic cell,and the volatilization of Cr from the metal substrate reduces the electrochemical activity of the electrode.The combined effect of the two leads to severe degradation of the per-formance of SOEC.In response to the above problems,Mn-Co coating and Mn-Co-La coating were prepared on commercial SUS430 metal sub-strate by electrophoretic deposition method.Subsequently,with using the process of successively sintering under neutral atmosphere(950℃,N_(2))and oxidizing atmosphere(825℃,air)conditions,the strong and dense Mn-Co coatings and Mn-Co-La coatings were obtained.Moreo-ver,the effects of sintering atmosphere and La element doping on coating properties were studied.The morphology,phase composition,element distribution and area specific resistance of the coatings were characterized by scanning electron microscope,X-ray diffractometer,energy spec-trometer and four-probe resistivity tester,respectively.Results showed that the coating prepared by electrophoretic co-deposition doping with trace amounts of nano-La_(2)O_(3)had more uniform and refined grains,which effectively inhibited the overflow of Fe-Cr from the substrate during high-temperature N_(2)sintering.The results of the 300 h oxidation cycle test at 750℃indicated that compared with the substrate,the sintering process proposed in this work was beneficial to improving the anti-oxidation performance of the coating,and the La-doped coating possessed better performance.Furthermore,the doping of La element effectively slowed down the volatilization of Cr in the substrate,which made the area specific resistance lower and more stable,and improved the high-temperature oxidation resistance of the Mn-Co spinel coating.
作者
吴建迪
王强
卢林
任衍伦
杨雁
孙兆松
郭土
王红涛
张莉
WU Jiandi;WANG Qiang;LU Lin;REN Yanlun;YANG Yan;SUN Zhaosong;GUO Tu;WANG Hongtao;ZHANG Li(School of Mechanical and Power Engineering,East China University of Science and Technology,Shanghai 200237,China;Dalian Research Institute of Petroleum and Petrochemicals,Sinopec Corp.,Dalian 116045,China)
出处
《材料保护》
CAS
CSCD
2023年第11期69-76,共8页
Materials Protection
基金
中央高校基本科研业务费专项资金(JKG01231709)资助。
