THE CORROSION AND THE ELECTROLYTE LOSS OF THE CATHODE SIDE CURRENT COLLECTOR MADE OF 16CR-12NI-2MO STAINLESS-STEEL IN MOLTEN-CARBONATE FUEL-CELLS

The corrosion of cathode side perforated current collectors made of 16 Cr-12Ni-2Mo stainless steel (AISI316L), which were used for molten car bonate fuel cells, have been analyzed after cell operations. Metal pen etration follows the parabolic rate low, and it is expected the metal penetration reaches 67 mu m after 40000hours operation. The activation energy of the metal penetration estimated was 145kJ/mol. The corrosio n scale was double layered and similar to the oxidation scale in CO2 g as atmosphere. The thickness ratio of outer layers / inner layers was constant of 56 / 44 after 3000hours operation. The outer scale was mad e from Li-Fe-O oxide such as LiFeO2, Li2Fe3O5 and LiFe5O8. The reactio n between ion oxide and lithium carbonate on the outer layer followed the parabolic rate low, and this was reasonable to explain the electro lyte consumption. However, LiCrO2 was not the main compound at the inn er layer with (Li0.62K0.38)(2)CO3.