Self-Assembled Nanocomposite Based on SrCo_0.7Fe_0.2Sc_0.1O_3-δ as an Efficient Intermediate-to-Low-Temperature SOFC...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• High performance of intermediate-to-low temperature solid oxide fuel cells (ILT-SOFCs) relies on cathode material activity.
• Strontium (Sr) rich perovskite cathodes suffer from Sr segregation, reducing activity and stability.

Purpose of the Study:

• To develop a self-assembled nanocomposite perovskite cathode to improve ILT-SOFC performance.
• To mitigate Sr segregation and enhance catalytic activity and long-term stability.

Main Methods:

• Synthesized SrCo_0.7Fe_0.2Sc_0.1O_3-δ (SCFSc) perovskite via controlled calcination.
• Created a nanocomposite cathode by self-assembly into cubic and tetragonal phases.
• Prepared a single cubic phase cathode for comparison.
• Evaluated oxygen reduction reaction (ORR) activity and electrochemical impedance.

Main Results:

• The nanocomposite cathode exhibited superior ORR catalytic activity compared to the single cubic phase.
• Lower impedance for oxygen surface exchange and bulk diffusion in the nanocomposite.
• Mitigated Sr segregation observed in the nanocomposite cathode.
• Achieved a peak power density of 1.17 W cm^-2 at 700 °C and stable operation for ~101 h at 600 °C.

Conclusions:

• Self-assembled nanocomposite perovskite cathodes offer a strategy to overcome Sr segregation issues.
• This approach enhances catalytic activity and long-term stability in ILT-SOFCs.