In-situ self-assembly nano-fibrous perovskite cathode excluding Sr and Co with superior performance for intermediate-temperature solid oxide fuel cells

The development of high-performance cathodes is crucial for intermediate temperature SOFCs. Thereinto, morphology regulation is an effective way to improve the electrocatalytic activity of SOFC cathodes. Nanofibers have been confirmed with the advantages of large specific surface area and high porosity over traditional nanoparticles, possessing a significant promotion effect on oxygen reduction reaction (ORR) activity. However, the traditional cell fabrication with high-temperature sintering will break the fiber structure and cause agglomeration. Herein, we adopted a sintering-free method to in-situ self-assemble La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCaFN) nanofibers onto the YSZ electrolyte surface by polarization operation, which showed impressive performance compared to our previous work. After polarization for 21 h, the peak power density of the cell at 700 °C increased from 0.36 W·cm−2 to 0.60 W·cm−2, and the highest peak power density at 750 °C could approach 0.91 W·cm−2. Meanwhile, the cell showed good long-term durability with a current density of about 0.35 A·cm−2 at 0.7 V and 650 °C for 90 h. This work manifests that the combination of fiber cathodes and in-situ self-assembly techniques is a promising strategy for high-performance SOFCs.