Development of Anode Supported Tubular Solid Oxide Fuel Cells with Low Cost and High Performance

摘要

The cells were composed of multiple layers (8YSZ electrolyte, Ni/8YSZ anode, and LaSrMnO3 cathode) and electrolyte buffer layers, placed on between electrolyte and cathode layers. The anode was extruded and fired to 1200o C followed by the electrolyte slurry coating and firing at 1450～1500°C. The cathode layer was fired at ～1200o C. The NiO-YSZ anode support tube were tailored and optimized to get better porosity, mechanical strength, and finally lower cost. For the cost reduction, the less expensive raw materials were used and non-oxide powders were evaluated as a support material. In addition, porosity and mechanical strength were enhanced by a change of YSZ matrix composition. In order to increase the power density, vacuum slurry coating method has been used for a flat and homogeneous electrolyte layer fabrication. The developed large scale tubular cell had a length of 0.5 meter and exhibited a power density as high as 370 mW/cm~2 at 0.7V and 800°C. In addition, the structure and fabrication process of interconnect-type current collector in anode supported tubular cell has been also carried out not only to investigate the effect of current collector geometry on the cell performance but also to make a compact bundle and stack without loss. The optimal condition of interconnect current collector has been established to minimize the resistance in the collector and current path of cell surface. Then, we are currently trying improvement of reduction-oxidation robustness of a cell and the long-term durability, and compactness of bundle for realization of SOFC module and system. In this study, we report the current status toward development finally for the large scale SOFC stack technology.