Performance of PrBaCo2O(5+delta) as a proton-conducting solid-oxide fuel cell cathode.

The potential application of PrBaCo(2)O(5+delta) (PBC) double perovskite oxide as a cathode for a proton-conducting solid-oxide fuel cell based on a BaZr(0.1)Ce(0.7)Y(0.2)O(3-delta) (BZCY) electrolyte was systematically investigated. XRD and O(2)-TPD results demonstrated that cation exchange between BZCY and PBC perovskites simultaneously occurs from the formation of Co(3+)-doped BZCY and Y(3+)-doped PBC. This event does not significantly change the cathodic polarization resistance. Under real fuel cell conditions, neither the electrolyte nor electrode resistances were significantly affected by the phase reaction and morphologic change of PBC. Anode-supported cells with an electrolyte thickness of approximately 30 microm were successfully fabricated via a dual dry pressing process. Relatively high performance of 520 and 407 mW cm(-2) at 700 degrees C was achieved for the cell with a PBC cathode fired at 950 and 1100 degrees C, respectively. A low electrode polarization resistance of 0.06 ohms cm(2) was achieved at 700 degrees C for the PBC cathode calcined at 950 degrees C.