In situ self-assembled NdBa0.5Sr0.5Co2O5+δ/Gd0.1Ce0.9O2-δ hetero-interfaces enable enhanced electrochemical activity and CO2 durability for solid oxide fuel cells

Abstract

The development of solid oxide fuel cells (SOFCs) faces impediments in terms of challenges associated with oxygen reduction activity and CO2 durability. Therefore, a series of novel composite cathode materials, consisting of NdBa0.5Sr0.5Co2O5+δ (NBSC) and Gd0.1Ce0.9O2-δ (GDC), were designed and synthesized using a one-pot strategy through a self-assembly process. The incorporation of GDC leads to a significant increase in the number of active sites. Furthermore, it alters the anisotropic transport properties of oxygen ions within layered double perovskite materials, consequently creating a three-dimensional conduit for O2– transportation. Simultaneously, the in-situ formation of closely intertwined heterogeneous interfaces between NBSC and GDC particles can facilitate the charge transfer processes and oxygen ion transport, thereby improving the kinetics of the oxygen reduction reaction (ORR). The NBSC-10GDC cathode, prepared through the one-pot method, exhibits reduced polarization resistances and enhanced CO2 tolerance in comparison to the mechanically mixed cathode. At 750 °C, the one-pot NBSC-10GDC exhibits a low area-specific resistance (ASR) of 0.029 Ω cm2, which is 69.8% lower than the ASR of single-phase NBSC and 42.0% lower than mechanically mixed NBSC-10GDC. Additionally, the one-pot NBSC-10GDC demonstrates a remarkable maximum power density (MPD) of 1.36 W cm−2 at 750 °C. These findings highlight the considerable potential of the one-pot NBSC-10GDC as a promising material for SOFC cathode.