Structural Robustness Engineering for NiFe Metal-Supported Solid Oxide Fuel Cells

The chromium-free oxide precursor strategy effectively avoids chromium volatilization and electrode contamination in metal-supported solid oxide fuel cells (MS-SOFCs), while enabling high-temperature co-sintering in air to simplify the fabrication process. However, the drastic microstructural coarsening, dimensional shrinkage, and thermal expansion mismatch with adjacent components of such substrates during high-temperature sintering, reduction, and thermal cycling collectively contribute to the interfacial instability and structural degradation of MS-SOFCs. Herein, we address these issues by incorporating a small amount of Gd0.1Ce0.9O1.95 (GDC) to the NiO-Fe2O3 (NFO) substrate. The incorporation of GDC significantly enhances the sintering compatibility and reduction stability of the MS-SOFCs, alleviating the stress-induced warping and distortion. Moreover, the GDC phase has a pinning effect to suppressing the coarsening of the substrates during high-temperature sintering and reduction processes, enhancing mechanical integrity and structural robustness of the single cell. With 15 wt% GDC incorporated into the NiFe substrate, the corresponding MS-SOFC with GDC electrolyte film achieves a peak power density of 0.56 W cm−2 at 600 °C, along with markedly improved structural integrity and operational reliability. This work demonstrates a viable pathway for designing heterophase-engineered supports with matched thermomechanical properties, offering promising prospects for enhancing the durability of MS-SOFCs.