Porous ceramic molten metal composite solid oxide fuel cell anode

Abstract

A fuel cell anode comprises a porous ceramic molten metal composite of a metal or metal alloy, for example, tin or a tin alloy, infused in a ceramic where the metal is liquid at the temperatures of an operational solid oxide fuel cell, exhibiting high oxygen ion mobility. The anode can be employed in a SOFC with a thin electrolyte that can be a ceramic of the same or similar composition to that infused with the liquid metal of the porous ceramic molten metal composite anode. The thicknesses of the electrolyte can be reduced to a minimum that allows greater efficiencies of the SOFC thereby constructed.

1 . A fuel cell anode, comprising a porous ceramic molten metal composite wherein a metal or metal alloy that is liquid at the use temperature of the fuel cell is infused into a porous ceramic. 
     
     
         2 . The anode of  claim 1 , wherein the metal or metal alloy comprises tin, bismuth, indium, lead, antimony, copper, molybdenum, mercury, iridium, palladium, rhenium, platinum, silver, arsenic, rhodium, tellurium, selenium, osmium, gold, germanium, thallium, cadmium, gadolinium, chromium, nickel, iron, tungsten, cobalt, zinc, or vanadium. 
     
     
         3 . The anode of  claim 1 , wherein the metal or metal alloy comprises tin. 
     
     
         4 . The anode of  claim 1 , wherein the porous ceramic comprises a doped CeO 2  or doped ZrO 2 . 
     
     
         5 . The anode of  claim 1 , wherein the porous ceramic comprises Gd-doped CeO 2  (GDC), Y-doped CeO 2  (YDC), Sm-doped cerium oxide (SDC), Sm—Nd-doped cerium oxide, yttria-stabilized zirconia (YSZ), Ca-stabilized zirconia, or Sc-stabilized zirconia (SSZ). 
     
     
         6 . The anode of claim , wherein the metal or metal alloy is liquid below 1,000° C. 
     
     
         7 . The anode of  claim 1 , wherein the metal or metal alloy is liquid below 650° C. 
     
     
         8 . A solid oxide fuel cell (SOFC), comprising:
 an anode layer comprising a porous ceramic molten metal composite;   a cathode layer comprising a metal oxide or mixed metal oxide; and   an electrolyte layer comprising an oxygen ion conductive ceramic.   
     
     
         9 . The SOFC of  claim 8 , wherein the porous ceramic molten metal composite comprises a metal or metal alloy comprising tin, bismuth, indium, lead, antimony, copper, molybdenum, mercury, iridium, palladium, rhenium, platinum, silver, arsenic, rhodium, tellurium, selenium, osmium, gold, germanium, thallium, cadmium, gadolinium, chromium, nickel, iron, tungsten, cobalt, zinc, or vanadium infused in a porous ceramic comprising Gd-doped CeO 2  (GDC), Y-doped CeO 2  (YDC), Sm-doped cerium oxide (SDC), Sm—Nd-doped cerium oxide, yttria-stabilized zirconia (YSZ), Ca-stabilized zirconia, or Se-stabilized zirconia. 
     
     
         10 . The SOFC of  claim 9 , wherein the porous ceramic molten metal composite comprises a molten tin or tin alloy infused GDC. 
     
     
         11 . The SOFC of  claim 8 , wherein the anode layer comprises a molten tin or tin alloy infused GDC and the electrolyte layer comprises GDC. 
     
     
         12 . The SOFC of  claim 8 , wherein the metal oxide or mixed metal oxide comprises a perovskite-type oxide. 
     
     
         13 . The SOFC of  claim 12 , wherein the perovskite-type oxide comprises LaMnO 3 , La 0.84 Sr0. 16 MnO 3 , La 0.84 Ca 0.16 MnO 3 , La 0.84 Ba 0.16 MnO 3 , La 0.65 Sr 0.35 Mn 0.8 Co 0.2 O 3 , La 0.79 Sr 0.16 Mn 0.85 CO 0.15 O 3 , La 0.84 Sr 0.16 Mn 0.8 Ni 0.2 O 3 , La 0.84 Sr 0.16 Mn 0.8 Fe 0.2 O 3 , La 0.84 Sr 0.6 Mn 0.8 Ce 0.2 O 3 , La 0.84 Sr 0.16 Mn 0.8 Mg 0.2 O 3 , La 0.84 Sr 0.16 Mn 0.8 Cr 0.2 O 3 , La 0.6 Sr 0.35 Mn 0.8 Al 0.2 O 3 , La 0.84 Scsub. 0.16 MnO 3 , La 0.84 Y 0.16 MnO 3 , La 0.7 Sr 0.3 CoO 3 , LaCoO 3 , La 0.7 Sr 0.3 FeO 3 , or La 0.5 Sr 0.5 CoO 0.8 Fe 0.2 O 3 . 
     
     
         14 . The SOFC of  claim 8 , wherein the metal oxide or mixed metal oxide comprises a composite of a perovskite-type oxide and a solid electrolyte. 
     
     
         15 . The SOFC of  claim 14 , wherein the perovskite-type oxide and the solid electrolyte metal oxide or mixed metal oxide comprises LSCF-GDC or LSM-YSZ. 
     
     
         16 . The SOFC of  claim 8 , wherein the metal oxide or mixed metal oxide comprises Bi 2 Ru 2 O 7  (BRO7), BRO7-(Er 2 O 3 ) 0.2 (Bi 2 O 3 ) 0.8  (ESB) composite, BRO-(Dw 2 O 3 ) 0.2 (Bi 2 O 3 ) 0.8 ) (DSB) composite, BRO-(Y 2 O 3 ) 0.2 (Bi 2 O 3 ) 0.8 ) (YSB) composite, or BRO-Bi 2−(x+y) Dy x W y O 3  (DWSB) composite. 
     
     
         17 . The SOFC of  claim 8 , wherein the electrolyte layer comprises Gd-doped CeO 2  (GDC), Y-doped CeO 2  (YDC), Sm-doped cerium oxide (SDC), or Sm—Nd-doped cerium oxide, yttria-stabilized zirconia (YSZ), Ca-stabilized zirconia, or Sc-stabilized zirconia (SSZ). 
     
     
         18 . The SOFC of  claim 8 , wherein the electrolyte layer comprises an oxygen ion conductive ceramic identical to the ceramic of the porous ceramic molten metal composite of the anode layer. 
     
     
         19 . The SOFC of  claim 8 , wherein the electrolyte layer comprises a bilayer electrolyte comprising a layer of an oxygen ion conductive ceramic identical to the ceramic of the porous ceramic molten metal composite of the anode layer and a layer of the metal oxide or mixed metal oxide of the cathode layer.