Highly efficient and robust cathode materials for low-temperature solid oxide fuel cells:...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Solid oxide fuel cells (SOFCs) offer efficient electricity generation from various fuels.
• Cathodic polarization remains a significant source of energy loss in SOFCs, especially at lower operating temperatures.
• Advancements in anode materials have improved tolerance to fuel impurities, but cathode performance needs further enhancement.

Purpose of the Study:

• To investigate the synergistic effect of co-doping in a cation-ordered double-perovskite material for SOFC cathodes.
• To enhance oxygen ion diffusion and surface oxygen exchange kinetics.
• To improve the overall efficiency and power density of SOFCs at reduced operating temperatures.

Main Methods:

• Synthesis and characterization of a co-doped cation-ordered double-perovskite material: PrBa0.5Sr0.5Co(2-x)Fe(x)O(5+δ).
• Fabrication and testing of SOFC test cells utilizing the developed cathode material.
• Evaluation of electrochemical performance, including power density and stability under operating conditions.

Main Results:

• The co-doped perovskite material exhibited synergistic effects, creating pore channels that enhance oxygen ion diffusion.
• Dramatic improvements in surface oxygen exchange kinetics were observed.
• Test cells achieved peak power densities of approximately 2.2 W cm(-2) at 600°C.
• The material demonstrated excellent compatibility and stability under SOFC operating conditions.

Conclusions:

• Co-doping of cation-ordered double-perovskites offers a promising strategy to mitigate cathodic polarization losses in SOFCs.
• The developed cathode material significantly enhances oxygen transport and surface reactions, leading to higher power densities.
• This advancement represents a crucial step towards the commercial viability of solid oxide fuel cell technologies at more accessible operating temperatures.