Development of a Ferritic Alloy Separator for a Planar SOFC

Heaトresistant ferriticl alloys were investigated for use as a SOFC separator materiai in order to reduce the difference in thermal expansion between the electrolyte and separator．The heat resistance offerritic alloys was improved by adding a small amount of lanthamm，making it possible to use them as a SOFC separator．The thermal cycle characteristics were improved in a50mm×50mm single celi using this ferritic alloy in comparison with a cell using an Ni-based alloy、The single cell was oper＆ted for about7000h，Degrada on of the ce performance was apparentiy mainly caused by gas leakage． 11NTRODUC「「ION Plan＆r-typesolidoxidefuelcells(SOFCs) have receive(1a great deal of attention because of their simple manufacturing process and the promise of a higher power density than that available from corresponding tubular designs． For the separator material，a heat-resistant alloy offers good performance in terms ofheat conductivity，mechanical strength and ease ofmanufacturing．Furthermore，its material cost is much lower than LaCrO3-based ceramics、Among heat．：resisting alloys， nicke1-based austenitic a】 loys have mainly been used so far．However，their thermal expansヌon coefflcient does not match that of