Fabrication of GdBaCo2O5+δ cathode using electrospun composite nanofibers and its improved electrochemical performance

GdBaCo2O5+δ (GBCO)/poly (vinyl pyrrolidone) (PVP) composite nanofibers were prepared by electrospinning. Structural and morphological evolution of the GBCO/PVP fibers under calcinations at various temperatures was studied. Using 600 °C pre-calcined GBCO/PVP composite nanofibers, pure phase GBCO cathode with homogeneous network structure was easily fabricated on Ce0.9Gd0.1O1.95 (GDC) electrolyte. The as-prepared GBCO cathode was characterized by electrochemical impedance spectra (EIS) measurements based on a GBCO/GDC/GBCO symmetric cell. Its electrochemical performance was compared with the cathode prepared with the GBCO powders synthesized with sol–gel method. The GBCO cathode fabricated using GBCO/PVP composite fibers had area specific resistances (ASRs) of 0.53 Ω cm2 at 600 °C, 0.22 Ω cm2 at 650 °C, 0.10 Ω cm2 at 700 °C and 0.043 Ω cm2 at 750 °C respectively, which are lower than ASR results of the GBCO cathode prepared with powders. The results have demonstrated that the GBCO cathode fabricated using electrospun composite nanofibers has significantly enhanced electrochemical activities for oxygen reduction reaction, and it can serve as a promising cathode material for intermediate-temperature solid oxide fuel cell.

► GBCO/PVP composite nanofibers were prepared by electrospinning.
► GBCO cathode with uniform network structure was easily prepared with nanofibers.
► The as-prepared GBCO cathode had improved electrochemical performance.