Performance of PrBaCo₂O₅₊ impregnated La_0.6Sr_0.4Co_0.2Fe_0.8O_3- composites as potential cathode materials for solid oxide fuel cells

The solution impregnation method was used to manufacture double perovskite PrBaCo2O5+delta (PBCO) impregnated La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) skeleton composite electrodes. The effects of different PBCO impregnation loadings on the electrochemical performance were investigated by experimental methods. Electrochemical impedance spectroscopy (EIS) results show that a proper amount (the mass of PBCO particles on the surface of electrode is about 10 wt% of LSCF framework) of PBCO impregnation significantly promotes the performance of original LSCF cathode, which reaches the polarization resistance (R-P) of 0.086 Omega cm(2) at 750 degrees C. Meanwhile, excessive impregnation of PBCO increases the R-p value of LSCF cathodes on the contrary. PBCO impregnation mainly affects the low-frequency region of the composite electrode, which is also confirmed by the electrical conductivity relaxation (ECR) and O-2 temperature programmed desorption (O-2-TPD) measurements. The concentration of oxygen vacancy and the oxygen adsorption capacity of the PBCO-LSCF composite electrodes were improved, thereby promoting its electrochemical performance. Moreover, the existence of the LSCF skeleton improves the mismatch problem of the thermal expansion coefficient between PBCO and GDC electrolyte. (C) 2021 Elsevier B.V. All rights reserved.