Methods of fabricating solid oxide fuel cells

Abstract

In various embodiments, a solid oxide fuel cell is fabricated in part by disposing a functional layer between the cathode and the solid electrolyte.

What is claimed is: 
     
         1 .- 16 . (canceled) 
     
     
         17 . A solid oxide fuel cell configured to operate at an operating temperature of less than 550° C., the solid oxide fuel cell comprising:
 a cathode; 
 a solid electrolyte for conducting oxygen ions from the cathode to an anode; 
 an anode for reacting oxygen ions from the solid electrolyte with a hydrogen-containing fuel; and 
 a functional layer disposed between the cathode and the solid electrolyte, 
 wherein the functional layer has a thickness of less than 5 μm. 
 
     
     
         18 . The solid oxide fuel cell of  claim 17 , wherein the thickness of the functional layer is greater than 0.1 μm. 
     
     
         19 . The solid oxide fuel cell of  claim 17 , wherein the solid oxide fuel cell is configured to operate at an operating temperature of 300° C. or more. 
     
     
         20 . The solid oxide fuel cell of  claim 17 , wherein the solid oxide fuel cell comprises an anode functional layer disposed between the anode layer and the solid electrolyte layer. 
     
     
         21 . The solid oxide fuel cell of  claim 20 , wherein the anode functional layer comprises (i) a cermet of nickel oxide and gadolinium-doped ceria, and/or (ii) a ceramic oxide material containing strontium, iron, cobalt, and molybdenum. 
     
     
         22 . The solid oxide fuel cell of  claim 20 , wherein a thickness of the anode function layer ranges from approximately 5 μm to approximately 50 μm. 
     
     
         23 . The solid oxide fuel cell of  claim 17 , wherein the functional layer comprises at least one of cobalt-doped gadolinium-doped ceria or cobalt-doped samarium-doped ceria. 
     
     
         24 . The solid oxide fuel cell of  claim 17 , wherein (i) the functional layer contains cobalt and (ii) at least a first portion of the solid electrolyte layer contains cobalt. 
     
     
         25 . The solid oxide fuel cell of  claim 24 , wherein a concentration of cobalt in the first portion of the solid electrolyte layer is less than a concentration of cobalt in the functional layer. 
     
     
         26 . The solid oxide fuel cell of  claim 24 , wherein a second portion of the solid electrolyte layer does not contain cobalt. 
     
     
         27 . The solid oxide fuel cell of  claim 26 , wherein the first portion of the solid electrolyte layer is disposed between the functional layer and the second portion of the solid electrolyte layer. 
     
     
         28 . A solid oxide fuel cell configured to operate at an operating temperature of greater than 550° C., the solid oxide fuel cell comprising:
 a cathode; 
 a solid electrolyte for conducting oxygen ions from the cathode to an anode; 
 an anode for reacting oxygen ions from the solid electrolyte with a hydrogen-containing fuel; and 
 a functional layer disposed between the cathode and the solid electrolyte, 
 wherein the functional layer has a thickness of greater than 5 μm. 
 
     
     
         29 . The solid oxide fuel cell of  claim 28 , wherein the thickness of the functional layer is less than 20 μm. 
     
     
         30 . The solid oxide fuel cell of  claim 28 , wherein the solid oxide fuel cell is configured to operate at an operating temperature of 800° C. or less. 
     
     
         31 . The solid oxide fuel cell of  claim 28 , wherein the solid oxide fuel cell comprises an anode functional layer disposed between the anode layer and the solid electrolyte layer. 
     
     
         32 . The solid oxide fuel cell of  claim 31 , wherein the anode functional layer comprises (i) a cermet of nickel oxide and gadolinium-doped ceria, and/or (ii) a ceramic oxide material containing strontium, iron, cobalt, and molybdenum. 
     
     
         33 . The solid oxide fuel cell of  claim 31 , wherein a thickness of the anode function layer ranges from approximately 5 μm to approximately 50 μm. 
     
     
         34 . The solid oxide fuel cell of  claim 28 , wherein the functional layer comprises at least one of cobalt-doped gadolinium-doped ceria or cobalt-doped samarium-doped ceria. 
     
     
         35 . The solid oxide fuel cell of  claim 28 , wherein (i) the functional layer contains cobalt and (ii) at least a first portion of the solid electrolyte layer contains cobalt. 
     
     
         36 . The solid oxide fuel cell of  claim 35 , wherein a concentration of cobalt in the first portion of the solid electrolyte layer is less than a concentration of cobalt in the functional layer. 
     
     
         37 . The solid oxide fuel cell of  claim 35 , wherein a second portion of the solid electrolyte layer does not contain cobalt. 
     
     
         38 . The solid oxide fuel cell of  claim 37 , wherein the first portion of the solid electrolyte layer is disposed between the functional layer and the second portion of the solid electrolyte layer.