Synergistically engineered in-situ self-assembled heterostructure composite nanofiber cathode with superior oxygen...

The engineering and exploration of cathode materials to achieve superior oxygen reduction catalytic activity and resistance to CO₂ are crucial for enhancing the performance of solid oxide fuel cells (SOFCs). Herein, a novel heterostructure composite nanofiber cathode comprised of PrBa_0.5Sr_0.5Co₂O_5+δ and Ce_0.8Pr_0.2O_1.9 (PBSC-CPO-ES) was prepared for the first time through a synergistic approach involving in-situ self-assembly and electrostatic spinning techniques. PBSC-CPO-ES exhibits exceptionally high oxygen reduction catalytic activity and CO₂ resistance, which is attributed to its unique nanofiber microstructure and abundant presence of heterointerfaces, significantly accelerating the charge transfer process, surface exchange and bulk diffusion of oxygen. The introduction of CPO not only effectively reduces the thermal expansion of PBSC but also changes the characteristics of oxygen ion transport anisotropy in layered perovskite materials, forming three-dimensional oxygen ion transport pathways. At 750 °C, the single cell employing the PBSC-CPO-ES heterostructure nanofiber attains an impressive peak power density of 1363 mW cm^-2. This represents a notable 60.7 % improvement in comparison to the single-phase PBSC powder. Moreover, PBSC-CPO-ES exhibits excellent CO₂ tolerance and performance recovery after CO₂ exposure. This work provides new perspectives to the design and advancement of future high-performance and high-stability SOFC cathode materials.