Enhanced Performance of La(0.8)Sr(0.2)FeO(3-δ)-Gd(0.2)Ce(0.8)O(2-δ) Cathode for Solid Oxide Fuel Cells by Surface Modification with BaCO(3) Nanoparticles

Recently, Fe-based perovskite oxides, such as Ln(1-x)Sr(x)FeO(3-δ) (Ln = La, Pr, Nd, Sm, Eu) have been proposed as potential alternative electrode materials for solid oxide fuel cells (SOFCs), due to their good phase stability, electrocatalytic activity, and low cost. This work presents the catalytic effect of BaCO(3) nanoparticles modified on a cobalt-free La(0.8)Sr(0.2)FeO(3-δ)-Gd(0.2)Ce(0.8)O(2-δ) (LSF-GDC) composite cathode at an intermediate-temperature (IT)-SOFC. An electrochemical conductivity relaxation investigation (ECR) shows that the K(chem) value of the modified LSF-GDC improves up to a factor of 17.47, demonstrating that the oxygen reduction process is effectively enhanced after surface impregnation by BaCO(3). The area-specific resistance (ASR) of the LSF-GDC cathode, modified with 9.12 wt.% BaCO(3), is 0.1 Ω.cm(2) at 750 °C, which is about 2.2 times lower than that of the bare cathode (0.22 Ω.cm(2)). As a result, the anode-supported single cells, with the modified LSF-GDC cathode, deliver a high peak power density of 993 mW/cm(2) at 750 °C, about 39.5% higher than that of the bare cell (712 mW/cm(2)). The single cells based on the modified cathode also displayed good performance stability for about 100 h at 700 °C. This study demonstrates the effectiveness of BaCO(3) nanoparticles for improving the performance of IT-SOFC cathode materials.