A more significant factor of life expectancy has to do with corrosion of the cathode.
The MCFC operating temperature is about 650°C (1200°F).
At this temperature the salt mixture is liquid and is a good conductor.
The cell performance is sensitive to operating temperature.
A change in cell temperature from 650°C (1200°F) to 600°C (1110°F) results in a drop in cell voltage of almost 15%.
The reduction in cell voltage is due to increased ionic and electrical resistance and a reduction in electrode kinetics.