Abstract
This work presents the results of elaboration of technology dedicated to fabrication of anode supported solid oxide fuel cells (AS-SOFC) with profiled surface of the anode. Profile on anode support was designed as channels which allow to facilitate the fluxes of gaseous components to and from electrochemical reaction zone due to the decreased thickness on Ni-YSZ composites between ribs. Additionally profiling of the anode increases the active area and allows elimination of the profiled or corrugated interconnectors. At state-of-the-art, in order to collect current from the surface of AS-SOFC and to ensure proper distribution of the fuel flow, interconnects are made from special heat-resistant alloys with precise milled or stamped channels. Profiled anode supports will allow to distribute gaseous fuel and replace dual-side profiled interconnects by cheaper ones without introduction of additional treatments or parts. In order to produce anode support with profiled surface without necessity of additional machining process of anode surface, the ceramic injection molding method (CIM) was used. This method significantly shortens the production time of the anode supports for AS-SOFCs, reduces its costs in comparison to commonly used techniques and is generates negligible amount of process waste material. This technique makes it possible to manufacture complex three dimensional ceramic components with tight dimensional tolerances. Cost-intensive post-processing can frequently be avoided, which allows high-scalable mass production of ceramic elements. The mold for injection of anode support was designed to make an anode support of 50x50 mm with 1.4 mm of thickness. The profile consisted of 18 channels was fabricated along of one side of the support. Dimensions of each channel were 0.6 mm of depth and 1.5 mm of width (Fig. 1). The geometry of channels defined using numerical simulations and then adjusted to the technological requirements of CIM. Using this mold the anode supports consisted of NiO/8YSZ 66/34 wt.% with porosity of 25 vol.% were injected (Fig. 1). The screen printing method was used to print 3 µm thick NiO anode contact layer, 7 µm thick NiO/8YSZ 50/50 wt.% anode functional layer, 4 µm thick 8YSZ dense electrolyte, 1.5 µm thick Gd0.1Ce0.9O2 barrier layer and the 30 µm thick La0.6Sr0.4Fe0.8Co0,2O3–δ cathode with porosity 25 vol.%. Sintering conditions were adjusted to avoid the deformation of the anode support. Fig.1. Schematic drawing of the profiled anode support (left) and the anode with fuel channels (right) Fabricated AS-SOFCs were characterized by the microstructural analysis and electrochemical performance was measured. Figure 1
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