Reverse Atom Capture on Perovskite Surface Enabling Robust and Efficient Cathode for Protonic Ceramic Fuel Cells

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Protonic ceramic fuel cells (PCFCs) are promising for sustainable energy.
• Sluggish cathode kinetics and poor stability limit PCFC performance.
• Developing advanced cathode materials is crucial for PCFC commercialization.

Purpose of the Study:

• To develop a facile and efficient method to improve PCFC cathode performance and stability.
• To engineer the surface chemistry of PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) cathodes.
• To investigate the impact of surface modification on the oxygen reduction reaction kinetics and durability.

Main Methods:

• Utilized a reverse atom capture technique to modify the PBSCF cathode surface.
• Introduced W species to capture segregated Ba and Sr cations, forming a (Ba/Sr)(Co/Fe/W)O3-δ (BSCFW)@PBSCF heterostructure.
• Fabricated and tested single PCFC cells with the modified cathode.

Main Results:

• The optimized 2W-PBSCF cathode achieved a peak power density of 1.32 W cm⁻² at 650 °C.
• The modified cathode demonstrated durable performance, maintaining stability for 240 hours.
• Theoretical calculations confirmed improved oxygen vacancy formation, hydration, and proton transfer energies in the BSCFW perovskite.

Conclusions:

• The reverse atom capture technique effectively enhances PCFC cathode performance and durability.
• The BSCFW@PBSCF heterostructure offers superior kinetics and stability for proton-involved reactions.
• This approach provides new strategies for designing advanced cathode materials for sustainable energy applications.