Cost-effective, Thin-film SOFCs for Reliable Power Generation (Final Report)
The project was aimed at developing and demonstrating an advanced solid-oxide fuel cell (SOFC) technology to cost-effectively and reliably generate electricity directly from hydrocarbon fuels (e.g., natural gas and coal-derived syngas) for distributed and central generation applications. The studied technology was built on a planar, porous metal-supported SOFC (MS-SOFC) with a unique thin-film structure having its anode intimately supported on a metal substrate. The porous metal support with graded porosity was fabricated from a low-cost scalable phase-inversion tape casting method. Anode, thin-film electrolyte, and cathode were sequentially deposited on the porous metal substrate using atmospheric plasma spray (APS). In this study, it was shown that the composition of the casting slurry could significantly influence the morphology of the metal support fabricated using the phase-inversion tape-casting method. Increasing the solid loading in the slurry favored the formation and growth of finger-like pores to a point, but the presence of excessive solid loading increased the viscosity of the casting slurry, restraining the growth of finger-like pores. With the increase in the amount of the binder polyethersulfone (PESf) in the slurry, well grown finger-like pores and a thin sponge-like layer were formed. Since the parameters of the APS process have a significant effect on the microstructure of coatings, which in turn affects or determines the SOFC cell performance, a series of metal-supported solid oxide fuel cells with a four-layer cell configuration of 430L/Ni-ScSZ/ScSZ/LSCF have been fabricated by a combination of phase inversion tape casting and APS techniques. Electrochemical testing of the cells fabricated from different deposition APS conditions revealed significant differences in cell performance.