LST-GDC 연료극 지지체용 SOFC 제작을 위한 Tape-casting 공정 및 전기화학적 특성 평가

초록

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.

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