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

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Proton-conducting solid-oxide fuel cells (SOFCs) are a promising clean energy technology.
• Developing efficient and stable cathode materials is crucial for SOFC performance.
• PrBaCo(2)O(5+delta) (PBC) is a double perovskite oxide with potential cathode applications.

Purpose of the Study:

• To investigate the application of PrBaCo(2)O(5+delta) (PBC) as a cathode material for proton-conducting solid-oxide fuel cells (SOFCs) with a BaZr(0.1)Ce(0.7)Y(0.2)O(3-delta) (BZCY) electrolyte.
• To analyze the interfacial reactions between the PBC cathode and BZCY electrolyte.
• To evaluate the electrochemical performance and stability of the fabricated SOFCs.

Main Methods:

• X-ray diffraction (XRD) and O(2)-temperature-programmed desorption (O(2)-TPD) were used to characterize the materials and interfacial reactions.
• Fabrication of anode-supported SOFCs with a thin BZCY electrolyte (approx. 30 microm) using a dual dry pressing process.
• Electrochemical performance testing, including power density measurements and electrode polarization resistance analysis at 700 degrees C.

Main Results:

• Simultaneous cation exchange between PBC and BZCY occurred, forming Co(3+)-doped BZCY and Y(3+)-doped PBC, without significantly impacting cathodic polarization resistance.
• The electrolyte and electrode resistances were not significantly affected by phase reactions or morphological changes of PBC under fuel cell conditions.
• SOFCs with PBC cathodes achieved power densities of 520 and 407 mW cm(-2) at 700 degrees C when the cathode was 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.

Conclusions:

• PrBaCo(2)O(5+delta) is a suitable cathode material for proton-conducting SOFCs with a BZCY electrolyte.
• The observed cation exchange at the interface does not detrimentally affect the electrochemical performance.
• The fabricated SOFCs demonstrate high performance, indicating the potential of PBC as an efficient cathode material for SOFC applications.