Ni-Fe Supported Solid Oxide Fuel Cells with an Open Graded-Pore Structure for Enhanced Mass Transport

Metal-supported solid oxide fuel cells (MS-SOFCs) are recognized as a critical pathway toward high-efficiency energy conversion and global sustainable development, owing to high mechanical robustness, low cost. However, MS-SOFCs are still limited by gas diffusion. To address this challenge, this study proposes an open graded-pore structure Ni-Fe (GP-NF) support fabricated via a double layer tape casting with a phase inversion process. A Ni-Fe layer is cast onto a graphite sacrificial layer. Through a dynamic solvent/non-solvent exchange process, a graded-pore structure consisting of a skin layer and finger-like pore layer is formed within the Ni-Fe support layer, while the sponge pore layer is generated within the graphite sacrificial layer. Subsequently, the graphite sacrificial layer beneath the Ni-Fe layer decomposes at high temperatures, thereby directly exposing the finger-like pore to air and forming the GP-NF support. The GP-NF support exhibits a high porosity of 53.2%. The polarization resistance ( R p ) of the GP-NF support SOFC is 0.21 Ω·cm 2 , which is 19.2% lower than that of a conventional single-layer tape casting Ni-Fe support (NF, 0.26 Ω·cm 2 ) SOFC. Therefore, the GP-NF support SOFC achieves a peak power density of 1.05 W·cm -2 at 800°C, representing a 72.1% enhancement over the NF support SOFC (0.61 W·cm -2 ). This work demonstrates an improvement in gas transport through strategic structural design, providing a feasible pathway for developing high-performance, highly reliable, and cost-effective MS-SOFCs.