Development of nanostructured lanthanum strontium cobalt ferrite/gadolinian-doped ceria composite electrodes of solid oxide cells formed by in situ polarization

In the development of nano-scale oxygen electrodes of the high temperature solid oxide cells (SOCs), the interface formed between the nanoelectrode particles and the electrolyte or electrolyte scaffolds is most critical. In this work, a new synthesis technique for the fabrication of nano-structured electrodes via in situ electrochemical polarisation treatment is reported. Lanthanum strontium cobalt ferrite (LSCF) precursor solution is infiltrated into gadoliniadoped ceria (GDC) scaffold pre-sintered on yttria-stabilized zirconia (YSZ) electrolyte, followed by in situ polarisation current treatment at SOC operation temperatures. Electrode ohmic and polarisation resistances decrease with the increase of polarisation current treatment. Detailed microstructure analysis indicates the formation of convex-shaped interface between LSCF nanoparticles (NPs) and GDC scaffold, very different from flat contact between LSCF and GDC observed after heated at 800oC with no polarization current treatment. The embedded LSCF NPs on GDC scaffold contribute to the superior stability under both fuel cell and electrolysis operation conditions at 750oC, and a high peak power density of 1.58 Wcm-2 at 750℃. This work highlights a novel and facile route to in-situ construct stable and highperforming nanostructured electrode for SOCs