Highly efficient and robust cathode materials for low-temperature solid oxide fuel cells: PrBa_0.5Sr_0.5Co_2-xFe_xO_5+δ

Solid oxide fuel cells (SOFC) are the cleanest, most efficient, and cost-effective option for direct conversion to electricity of a wide variety of fuels. While significant progress has been made in anode materials with enhanced tolerance to coking and contaminant poisoning, cathodic polarization still contributes considerably to energy loss, more so at lower operating temperatures. Here we report a synergistic effect of co-doping in a cation-ordered double-perovskite material, PrBa 0.5 Sr 0.5 Co 2-x Fe x O 5+δ, which has created pore channels that dramatically enhance oxygen ion diffusion and surface oxygen exchange while maintaining excellent compatibility and stability under operating conditions. Test cells based on these cathode materials demonstrate peak power densities ∼2.2â€...W cm -2 at 600 C, representing an important step toward commercially viable SOFC technologies.