Development of Porous Metal Substrate for Thin-Film Solid Oxide Fuel Cells (TF-SOFCs)

Thin-film solid oxide fuel cells (TF-SOFCs) deposited by magnetron sputtering are highly desirable due to their increased power output at reduced operating temperatures (<800 °C). Metallic porous substrates can provide mechanical support, gas supply, and current collection for TF-SOFCs and at the same time facilitate stack design, integration, and operation. A study was conducted to develop a porous metal support that is compatible with the sputtering process while offering thermal compatibility with the cell. In this study, a microporous nickel-based alloy (Inconel) modified with nanoporous nickel (NP-Ni) and yttria-stabilized zirconia (YSZ) nanoparticles has been developed as a substrate for TF-SOFCs fabricated by sputtering. Both theoretical simulations and experimental results have indicated that Inconel offers high resistance to cell bending and crack formation compared to porous nickel (Ni) substrates. A thin-film cell, less than 8 μm thick, was successfully deposited onto the Inconel substrate via sputtering. This cell demonstrated an open-circuit voltage (OCV) of 1.06 V and a peak power density of 1.07 W/cm2 using hydrogen fuel and air at 600 °C. The cells exhibited the highest performance among metal-supported TF-SOFCs at reduced temperatures, highlighting the feasibility of combining porous metal substrates with thin-film deposition processes to produce superior-performance, reduced-temperature SOFCs.