Over the history of solid oxide fuel cell (SOFC) development, many investigators have sought to reduce the operating temperature. In this article, we present and discuss factors that lead to a lower limit on the effective operating temperature of these fuel cells. Among these factors, the cathode polarization resistance and fuel oxidation on the anode show the greatest effects on limiting low‐temperature operation. The strontium‐doped lanthanum manganite cathode is limited to ≥800 °C for 0.6 W cm
−2
at 0.85 V. Mixed‐ionic and electronic conducting materials are more active and can operate at ∼750 °C, but they are more prone to interact with the yttria‐stabilized zirconia (YSZ) electrolyte. Modified Ni‐based/YSZ anodes operating on carbonaceous fuels have a thermodynamic temperature limit of 500 °C because of carbon formation in the absence of steam, but also need to have their power densities improved to operate below 650 °C. The electrolyte resistance is not a significant factor for 8 mol% YSZ being able to operate as low as 530 °C, and for other electrolytes at even lower temperatures. Also, the electrical resistance of the interconnect, including that of the protective scale on metallic interconnects, becomes significant at temperatures below 600 °C. Cell geometry is another factor that limits low‐temperature operation, favoring planar over other stack designs.
This paper presents an advanced design and fabrication concept for a solid oxide fuel cell (SOFC). The concept is based on a laminate repeat unit comprised of a thin electrolyte, cermet anode, metallic gas flow fields, and a metallic bipolar plate. The laminate is sintered in a singlestep process in a controlled atmosphere, and the cathode is applied and sintered in situ during the initial heating of the cell (or stack). Observations about the types of cracks that formed in the electrolyte during the sintering process guided the development of the sintering protocol to yield the desired product. Cells with power densities exceeding 250 mW/cm2 have been tested.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.