A Durable Ruddlesden-Popper Cathode for Protonic Ceramic Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Protonic ceramic fuel cells (PCFCs) are efficient energy converters at intermediate temperatures.
• Developing durable and efficient cathodes is crucial for enhancing PCFC performance, particularly for the proton-involved oxygen reduction reaction (p-ORR).

Purpose of the Study:

• To develop a novel single-phase cathode material for PCFCs.
• To investigate the potential of a new triple-layered Ruddlesden-Popper (R-P) structure oxide, Sr₃EuFe₂.₅Co₀.₅O₁₀-δ (3-SEFC₀.₅), as a PCFC cathode.
• To evaluate the electrochemical performance and stability of PCFCs utilizing the developed cathode.

Main Methods:

• Synthesis of a new triple-layered R-P oxide, Sr₃EuFe₂.₅Co₀.₅O₁₀-δ (3-SEFC₀.₅).
• Characterization of the material's structural, thermal, and oxygen non-stoichiometry properties.
• Electrochemical testing of PCFCs with the 3-SEFC₀.₅ cathode to measure polarization resistance and power density.

Main Results:

• The developed 3-SEFC₀.₅ cathode exhibited high oxygen non-stoichiometry and desirable structural thermal stability.
• PCFCs employing the 3-SEFC₀.₅ cathode achieved unprecedented low polarization resistances (approx. 0.030 Ω·cm²) and high peak power densities (approx. 900 mW·cm⁻²) at 700°C.
• The single-phase cathode demonstrated high activity and stability for the p-ORR.

Conclusions:

• Optimal doping in multi-layered perovskite structures can significantly improve structural stability and electrocatalytic activity.
• Multi-layered R-P series oxides show great potential as highly active and durable catalysts for PCFCs.
• The 3-SEFC₀.₅ material represents a promising advancement for high-performance PCFC applications.