In this study, we developed a composite anode support composed of La-doped SrTiO3 (LST) and Gd-doped CeO2 (GDC) using a tape casting process for solid oxide fuel cells (SOFCs). By adjusting the pore former content in the slurry, we constructed a bilayered structure consisting of a porous anode support layer (ASL) and a dense anode functional layer (AFL) with the same material composition. The number of tape-cast sheets was controlled to tailor the overall thickness, and lamination followed by co-sintering at 1250oC resulted in a mechanically robust bilayer. We characterized the microstructural evolution concerning sintering temperature and pore former content using SEM, while XRD confirmed the phase stability of LST and GDC. The measured electrical conductivity at 750oC ensured sufficient electron transport. To enhance interfacial adhesion and suppress secondary phase formation, we introduced a GDC buffer layer and a pre-sintering treatment prior to electrolyte deposition. A full cell with a YSZ electrolyte and LSCF cathode achieved a stable open circuit voltage of approximately 0.7 V and demonstrated continuous operation at 750oC. These findings highlight the suitability of LST-GDC composite anodes as thermochemically stable supports, potentially enabling direct hydrocarbon utilization in intermediate-temperature SOFCs.
This study quantitatively examines the impact of ultraviolet (UV) intensity and energy on the formation of high aspect ratio (HAR) microstructures using the Self-Propagating Photopolymer Waveguide (SPPW) process. This mechanism relies on the self-focusing of UV light within a refractive index gradient, allowing the light to propagate and polymerize vertically beyond the initial exposure zone. Experiments were performed at UV intensities of 7.5, 12.5, and 17.5 mW/cm2, with energy levels ranging from 0.0375 to 13.5 J/cm2. The results indicated that a lower UV intensity of 7.5 mW/cm2 produced uniform and vertically elongated structures, achieving a maximum aspect ratio of 12.26 at 0.9 J/cm2. In contrast, higher UV intensities led to lateral over-curing, base expansion, and shape distortion, primarily due to rapid polymerization and the oxygen inhibition effect. These findings emphasize the importance of precisely controlling both UV intensity and energy to produce uniform, vertically aligned HAR microstructures, offering valuable insights for optimizing the SPPW process in future microfabrication applications.
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