Anode-supported tubular solid oxide fuel cell stack and method of fabricating the same

A method of fabricating an anode-supported tubular solid oxide fuel cell stack, comprising the steps of:

• providing carbon powders as a pore forming agent to mixed powders of NiO containing 30 to 50 vol % of Ni metal with YSZ powders in an amount of 20 to 50 vol % and ball-milling a resulting mixture to produce powders for an anode-supported tube;
• adding distilled- water, organic binding agents, plasticizers, and lubricants to the powders for the anode-supported tube, mixing them in a mixer so as to provide an extrusion property to the powders for the anode-supported tube, and seasoning a resulting mixture so as to uniformly disperse water in the resulting mixture to produce a paste for extrusion;
• extruding the paste into the anode-supported tube;
• pre-sintering the anode-supported tube at 1250 to 1400° C.;
• mixing the YSZ powders with an additive in an organic solvent to produce an electrolyte slurry;
• dipping the anode-supported tube into the electrolyte slurry to coat an electrolyte slurry layer on a surface of the anode-supported tube after a band-type organic film layer is longitudinally formed on a circumferential surface of the anode-supported tube;
• removing the organic film layer from the anode-supported tube, drying the electrolyte slurry layer at 300 to 450° C., and sintering a dried electrolyte slurry layer at 1350 to 1500° C to form an electrolyte layer;
• coating a ceramic connector material with an electronic conductivity on a portion of the anode-supported tube in which the organic film layer was formed by a dipping type wet process;
• drying the anode-supported tube covered with a band-type ceramic connector material at 300 to 450° C. and sintering a dried anode-supported tube at 1350 to 1500° C. to form a band-type ceramic connector;
• covering an organic protective film layer on a surface of the band-type ceramic connector, coating an air electrode on a surface of the electrolyte layer with the use of the liquid slurry for the air electrode containing LaSrMnO3 powders by a dipping type slurry coating process;
• removing the organic protective film layer formed on the surface of the band-type ceramic connector, and sintering a resulting air electrode at 1150 to 1250° C. to complete a unit cell;
• and
• upwardly stacking metal connector plates in the order of a lower connector plate, a fuel cell, middle connector plates, a fuel cell, and an upper connector plate, and connecting stack electrodes to the lower connector plate and the upper connector plate, respectively, said lower connector plate provided on only an upper side thereof with a plurality of first semicircular grooves and a plurality of first square grooves being at right angles to the first semicircular grooves, said middle connector plates each provided on an upper and a lower side thereof with a plurality of second semicircular grooves and a plurality of second square grooves being at right angles to the second semicircular grooves, said upper connector plate provided on only a lower side thereof with a plurality of third semicircular grooves and a plurality of third square grooves being at right angles to the third semicircular grooves.