FUEL CELL STACK AND FLAT-PLATE SOLID OXIDE FUEL CELL USING SAME

摘要

A fuel cell stack free of both lowering of the cell voltage and cracks of the solid electrolyte due to the action of the mechanical stress and a flat-plate solid oxide fuel cell using the same are disclosed. The fuel cell stack has a seal-less structure in which generating cells (16) are stacked in the direction of the plate thickness, with separators (2) interposed therebetween. Each generating cell (16) has a fuel electrode layer (12) formed on the (lower) surface of a solid electrolyte flat plate (11) and an oxidant electrode layer (13) on the (upper) surface thereof. Fuel electrode current collectors (14) are interposed between the fuel electrode layers and separators, and oxidant electrode current collectors (15) are interposed between the oxidant electrode layers and the separators. A ring member (17) thinner than the fuel electrode current collectors or a bulge low enough to be out of contact with the solid electrolyte formed at the fuel electrode current collector side of each separator is provided around the periphery of each fuel electrode current collector.