INTERACTION BETWEEN CHROMIA FORMING ALLOY INTERCONNECTS AND AIR ELECTRODE OF SOLID OXIDE FUEL-CELLS

The performance of solid oxide fuel cells, especially on the air side, degrades very rapidly when chromia forming alloys are used as interco nnects in contact with electrodes. The effect of chromia forming alloy s on the performance of doped LaMnO3 air electrode has been studied at the current fuel cell operating temperatures in the vicinity of 900-1 000 degrees C. Interactions between a chromium-rich allay and doped La MnO, were studied during testing of fuel cell stacks as well as in spe cially designed electrochemical experiments. On completion of these ex periments interconnect/electrode and electrode/ electrolyte interfaces as well as interconnect, electrode and electrolyte materials were exa mined with scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and optical microscopy. A mechanism for cell performance degradation based on these observations has been proposed.