固体氧化物燃料电池合金连接体涂层材料研究进展

固体氧化物燃料电池(SOFC)向中温化发展,使得用金属材料作连接体成为可能.但是金属连接体在SOFC工作的高温氧化和湿氢环境中,其使用寿命受到严重限制,需要表面保护层.常用钙钛矿结构和尖晶石结构类的氧化物作为金属涂层材料.在合金表面涂覆致密氧化物涂层很关键,通过涂层材料与合金挥发出的Cr类元素之间的化学反应,可以降低Cr挥发,减弱Cr对阴极的毒化,阻止合金的进一步氧化.涂层材料还需要有高的电子电导率,与合金匹配的热膨胀性能,以降低界面电阻,防止涂层脱落.目前,还没有哪一种材料能够满足这多方面的要求,因此合金保护涂层材料还需要进一步的研究.

Development of Coating Materials on Alloy Interconnect in Solid Oxide Fuel Cell

It is possible for Solid Oxide Fuel Cell (SOFC) to use the alloy as interconnect due to that the SOFC's operation temperature lowers to the middle temperature of 600～800 ℃. In order to prolong the life of alloy in the SOFC operating condition, e.g. high-temperature oxidation and humid hydrogen, it is necessary to coat the protect layers. The perovskite and spinel oxide are usually optimized as the coating materials on alloys. It is important to deposite dense oxides of coatings on the surface of metallic alloy, which could decrease the oxidation rate of alloys and reduce the poison of Cr to cathode by reacting with Cr that vaporizes from the alloys. The high electrical conductivity of the coating materials is required to lower the interlayer resistance, and the thermal expansion coefficient (TEC) of it should match that of alloys in order to prevent the coating layer from falling off. Up to now, there are not the optimized coating materials to satisfy the above properties. Therefore, the research works should be continued in the areas.