High performance metal-supported solid oxide fuel cells with Ni–Fe alloy support

Replacing the ceramic support of a conventional solid oxide fuel cell (SOFC) with a metal support is an active research trend for improving the robustness of SOFC. We report metal-supported SOFC (M-SOFC) prepared based on Ni–Fe alloy supports with different Ni to Fe atomic ratios. The results show a Ni to Fe atomic ratio of 7:3 ratio has a more homogeneous and balanced microstructure and mechanical strength. Besides metal support selection, the type of cathode also plays a key role on improving the performance of a M-SOFC. In this study, we choose SSC and SDC as cathode materials and prepare composite cathodes containing different weight ratios of SSC to SDC, i.e., 3:7, 5:5, and 7:3 with a cathode sintering temperature of 950 and 1050 °C are compared as well. The combination of a Ni to Fe atomic ratio of 7:3, a SSC to SDC weight ratio of 5:5, and a cathode sintering temperature of 1050 °C yields the highest performance. The SSC-SDC55 cathode on symmetrical cell test shows a very low polarization resistance of 0.035 Ω cm 2 at 800 °C. A tested single-cell consisting layers of Ni–Fe|NiO-YSZ|YSZ|GDC|SSC- SDC achieved a maximum power density of 1.4 W cm −2 at 800 °C, reaching one of the highest performances for Ni–Fe supported M-SOFC, proving the advantages of using Ni–Fe alloy as support for M-SOFC. The stability of our Ni–Fe alloy supported M-SOFC still needs improvement.