固体氧化物燃料电池金属连接体材料

本文简述了固体氧化物燃料电池(SOFC)连接体材料的发展过程,重点介绍了金属连接体材料的研发现状。目前研究和使用的合金有三种:Cr基合金、Ni基合金和铁素体不锈钢。Cr基合金的耐热温度能达到SOFC的要求,并且其表面氧化后生成的Cr2O3有很高的电导率,但是Cr元素的挥发很容易引起阴极中毒而降低电池性能;Ni基合金有很高的抗氧化性,但其热膨胀系数(TEC)比电解质(如YSZ)大很多,热膨胀系数的不匹配很容易造成电池破裂;铁素体不锈钢能满足SOFC所要求的强度,并且有合适的热膨胀系数,但是也需要在其表面制备保护层来降低氧化速率和Cr挥发。本文以有代表性的合金作为例子对三种合金的性质作了总结,并给出了本实验室所开发的几种Fe-Cr高温合金(铁素体不锈钢)的性能。最后总结了合金连接体的发展方向。

Metallic Interconnect Materials Used in Solid Oxide Fuel Cell

The development of interconnect materials used in SOFC had been simply reviewed,and the metallic interconnect materials was introduced in detail in this paper.Now,three kinds of alloys were studied and applied:Cr-former alloy,Ni-based alloy and the ferritic steel.The highest applied temperature of Cr-former alloy is possible for SOFCs,and the oxide Cr2O3 formed on the alloy has an accepted electrical conductivity,but the cathode could be easily poisoned by Cr volatilizing from the alloy substrate.Ni-based alloy has a good oxide resistance,but its thermal expansion coefficient(TEC)is much larger than the electrolyte(e.g.,YSZ),which would easily induce the fracture of the cell itself.The strength character and the TEC of the ferritic steel fit the requirement of SOFCs,while a protecting coating must be made to decrease the rate of oxidation and Cr volatilization.In this paper,the characters of the three kinds alloy had been summarized,and some of the author's work had been presented,then the development orientation of the metal interconnect was given.