Effect of Fuel Depletion on Ni-YSZ Anode Supported Membrane Fuel Cell Under Different Discharge Modes

In this work, button single cells with Ni-YSZ (anode support) | YSZ (electrolyte membrane) | Gd0.1Ce0.9O1.95 (barrier layer) | La0.6Sr0.4Co0.2Fe0.8O3-?(cathode) structure produced by mass-producing under industrial conditions were operated with dry hydrogen as fuel. In order to simulate single cell unit failure in series stack and local region failure of one cell, fuel gas depletion experiments were carried out in constant current and constant voltage discharge modes, respectively. During the discharging processes, the hydrogen fuel was fed and cut off alternatively for several times with different cut-off time, the output performances were measured to evaluate the stability and healthy of the single cell. The results show that the long time fuel depletion of the cell discharging in constant current mode can directly destroy the cell, it means a cell unit's life in series stack can be affected when suffered fuel depletion. However, the cell discharging in constant voltage mode can keep stable status under fuel depletion condition, it means that the local fuel depletion in a certain cell will not destroy it.