Interconnection and Sealing Using Silver Metal for Honeycomb SOFCs

Abstract

An interconnection and sealing method used for stacking the electrolyte-supported honeycomb solid oxide fuel cells (SOFCs) is presented. The honeycombs were made of 3mol% yttria partially stabilized zirconia and 8mol% yttria stabilized zirconia with 3×3 channels. The size of each channel was 5×5mm2 and 20mm long. The thickness of the channel walls is 1mm. The electrode materials were Ni-cermet and lanthanum strontium manganite. Newly designed metal plates with insulation layers were used for the interconnection and gas sealing between the honeycomb single cells. An open circuit voltage (OCV) of 2.19V was obtained at 800°C using a two-cell stack. A small amount of OCV reduction was observed during a thermal cycling. However, the high values of the OCVs and the stable current indicated preferable electric connections, and lower gas leakage. The successful test shows that the interconnection and sealing method with the proposed interconnect plates is promising for honeycomb SOFC stacks.