Developing abundant rare-earth iron perovskite electrodes for high-performance and low-cost solid oxide fuel cells.

The swift advancement of the solid oxide fuel cell (SOFC) sector necessitates a harmony between electrode performance and commercialization cost. The economic value of elements is frequently linked to their abundance in the Earth's crust. Here, we develop abundant rare-earth iron perovskite electrodes of Ln0.6Sr0.4FeO3-δ (Ln = La, Pr, and Nd) with high abundant rare-earth metals and preferred iron metal for SOFCs. All three symmetric electrode materials display a cubic perovskite phase and excellent chemical compatibility with Gd0.2Ce0.8O2-δ electrolyte. All three electrodes possess exceptional surface oxygen exchange ability. At 800°C, single cells with La0.6Sr0.4FeO3-δ, Pr0.6Sr0.4FeO3-δ, and Nd0.6Sr0.4FeO3-δ symmetric electrodes attained excellent open circuit voltages of 1.108, 1.101, and 1.097 V, respectively, as well as peak powers of 213.52, 281.12, and 254.58 mW cm-2. The results suggest that overall performance of abundant rare-earth iron perovskite electrodes has a favorable impact on the extensive expansion of SOFCs, presenting significant potential for practical applications.

Enhanced Performance of La0.8Sr0.2FeO3-δ-Gd0.2Ce0.8O2-δ Cathode for Solid Oxide Fuel Cells by Surface Modification with BaCO3 Nanoparticles.

Recently, Fe-based perovskite oxides, such as Ln1-xSrxFeO3-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 BaCO3 nanoparticles modified on a cobalt-free La0.8Sr0.2FeO3-δ-Gd0.2Ce0.8O2-δ (LSF-GDC) composite cathode at an intermediate-temperature (IT)-SOFC. An electrochemical conductivity relaxation investigation (ECR) shows that the Kchem 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 BaCO3. The area-specific resistance (ASR) of the LSF-GDC cathode, modified with 9.12 wt.% BaCO3, is 0.1 Ω.cm2 at 750 °C, which is about 2.2 times lower than that of the bare cathode (0.22 Ω.cm2). As a result, the anode-supported single cells, with the modified LSF-GDC cathode, deliver a high peak power density of 993 mW/cm2 at 750 °C, about 39.5% higher than that of the bare cell (712 mW/cm2). 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 BaCO3 nanoparticles for improving the performance of IT-SOFC cathode materials.