System and method for manufacturing fuel cell stacks

Abstract

A fuel cell stack comprises multiple fuel cell assemblies, wherein each fuel cell assembly includes a fuel cell comprising an anode layer and a cathode layer, and an electrolyte interposed between the anode layer and the cathode layer. The fuel cell assembly further comprises an anode interconnect and a cathode interconnect, wherein the anode interconnect may be firmly attached to the anode layer by means of a bonding agent and a sealing agent used to seal passages on the anode layer of each fuel cell.

1 . A method of manufacturing a fuel cell assembly, comprising the steps of: 
 sealing at least a cathode interconnect with a cathode layer of a fuel cell, wherein the fuel cell comprising the cathode layer, an electrolyte and an anode layer;    reducing the anode layer using a reducing gas; and    bonding the anode layer with an anode interconnect using a sealing agent to form the fuel cell assembly.    
     
     
         2 . The method of  claim 1 , further comprising heating the fuel cell assembly prior to bonding the anode layer with the anode interconnect.  
     
     
         3 . The method of  claim 1 , wherein reducing the anode layer using the reducing gas occurs prior to bonding the anode layer with the anode interconnect.  
     
     
         4 . The method of  claim 1 , wherein reducing the anode layer using the reducing gas and bonding the anode layer with the anode interconnect are performed at substantially the same time.  
     
     
         5 . The method of  claim 1 , further comprising testing and inspecting the fuel cell assembly for defects.  
     
     
         6 . The method of  claim 5 , wherein testing and inspecting the fuel cell assembly includes performing a leak test, a resistance measurement test, an impedance measurement test, a mechanical integrity test, an ultrasound test, a X-ray test, an infrared imaging measurement, measurement of open circuit voltage, an impedance spectroscopy or an electrochemical performance test or combinations thereof.  
     
     
         7 . The method of  claim 1 , further comprising stacking a plurality of fuel cell assemblies to form a pseudostack prior to reducing the anode layer.  
     
     
         8 . The method of  claim 7 , further comprising reducing the anode layer of each fuel cell assembly in the pseudostack using the reducing gas.  
     
     
         9 . The method of  claim 7 , further comprising sealing each of the fuel cells in the pseudostack to either the anode interconnect or the cathode interconnect.  
     
     
         10 . The method of  claim 7 , further comprising testing and inspecting the individual fuel cells in the pseudostack for defects.  
     
     
         11 . The method of  claim 10 , wherein testing and inspecting the individual fuel cells in the pseudo stack includes performing a leak test, a resistance measurement test, an impedance measurement test, a mechanical integrity test, an ultrasound test, a X-ray test, an infrared imaging measurement, measurement of open circuit voltage, an impedance spectroscopy or an electrochemical performance test or combinations thereof.  
     
     
         12 . The method of  claim 1 , wherein the reducing gas comprises hydrogen.  
     
     
         13 . The method of  claim 1 , wherein the anode interconnect comprises an electrically conductive material selected from the group consisting of stainless steel, stainless steel alloys, nickel, nickel alloys, fecralloy, nichrome, gold, silver, platinum, palladium, ruthenium, or rhodium, electronically conductive ceramic or combinations thereof.  
     
     
         14 . The method of  claim 1 , wherein the cathode interconnect comprises an electrically conductive material selected from the group consisting of stainless steel, stainless steel alloys, fecralloy, nichrome, gold, silver, platinum, palladium, ruthenium, or rhodium, electronically conductive ceramic or combinations thereof.  
     
     
         15 . The method of  claim 1 , wherein the anode interconnect includes channels to supply the reducing gas to the anode layer.  
     
     
         16 . The method of  claim 1 , wherein the cathode interconnect is configured to have channels to supply an oxidant gas to the cathode layer.  
     
     
         17 . The method of  claim 1 , further comprising bonding the cathode interconnect and the anode interconnect using an impermeable surface separating them.  
     
     
         18 . The method of  claim 1 , wherein the cathode interconnect and the anode interconnect are manufactured from a single piece of metal by a process of machining or stamping.  
     
     
         19 . The method of  claim 17 , wherein the cathode interconnect and the anode interconnect are bonded by welding, brazing, diffusion bonding, or some other process resulting in an electrically conductive bond.  
     
     
         20 . The method of  claim 17 , wherein the impermeable surface comprises an electrically conductive plate made of material selected from the group consisting of stainless steel, stainless steel alloys, fecralloy, nichrome, gold, silver, platinum, palladium, ruthenium, or rhodium or combinations thereof.  
     
     
         21 . The method of  claim 1 , wherein the anode layer comprising substantially of nickel reduced from nickel oxide by introducing the reducing gas to the anode layer.  
     
     
         22 . The method of  claim 1 , wherein the anode layer includes Nickel, Nickel Alloy, Ag, Cu, Cobalt, Ruthenium, Ni—YSZ cermet, Cu—YSZ cermet, Nickel-Ceria cernet, or combinations thereof.  
     
     
         23 . A method of manufacturing one or more fuel cell assemblies, comprising the steps of: 
 assembling a pseudostack comprising the one or more fuel cell assemblies, wherein each fuel cell assembly comprising a first electrode, an electrolyte, a second electrode, a first interconnect and a second interconnect;    disposing a sealing agent between perimeter of either the first electrode and the first interconnect or the second electrode and the second interconnect of each of the fuel cell assembly;    disposing a bonding agent between either the first electrode and the first interconnect or the second electrode and the second interconnect of each fuel cell assembly; and    heating the pseudostack for curing the sealing agent and the bonding agent.    
     
     
         24 . The method of  claim 23 , further comprising introducing a reducing gas to at least the first electrode or the second electrode of each fuel cell assembly in the pseudostack for chemically reducing the first electrode or the second electrode.  
     
     
         25 . The method of  claim 23 , further comprising removing defective fuel cell assemblies in the pseudostack.  
     
     
         26 . The method of  claim 23 , further comprising testing individual fuel cell assemblies in the pseudostack for defects.  
     
     
         27 . The method of  claim 26 , wherein testing and inspecting individual fuel cell assembly includes performing a leak test, a resistance measurement test, an impedance measurement test, a mechanical integrity test, an ultrasound test, a X-ray test, an infrared imaging measurement, measurement of open circuit voltage, an impedance spectroscopy or an electrochemical performance test or combinations thereof.  
     
     
         28 . A fuel cell assembly comprising a fuel cell, wherein the fuel cell comprises an anode layer, a cathode layer and an electrolyte interposed therebetween and wherein the fuel cell assembly is formed by: 
 reducing the anode layer via a reducing gas; and    bonding the anode layer with an anode interconnect using a sealing agent to form the fuel cell assembly prior to sealing a cathode interconnect with the cathode layer.    
     
     
         29 . The fuel cell assembly of  claim 28 , wherein reducing the anode layer via the reducing gas occurs prior to bonding the anode layer with the anode interconnect or the cathode layer with the cathode interconnect.  
     
     
         30 . The fuel cell assembly of  claim 28 , wherein reducing the anode layer via the reducing gas and bonding the anode layer with the anode interconnect or the cathode layer with the cathode interconnect occur at substantially the same time.  
     
     
         31 . The fuel cell assembly of  claim 28 , wherein the anode layer comprising substantially of nickel reduced from nickel oxide by introducing the reducing gas to the anode layer.  
     
     
         32 . A fuel cell stack comprising one or more fuel cell assemblies formed by: 
 reducing an anode layer via a reducing gas;    bonding the anode layer with an anode interconnect using a sealing agent to form the fuel cell assembly prior to sealing a cathode interconnect with a cathode layer; and    stacking the one or more fuel cell assemblies to form the fuel cell stack.    
     
     
         33 . The fuel cell stack of  claim 32 , further comprising rejecting defective fuel cell assemblies.  
     
     
         34 . The fuel cell stack of  claim 32 , further comprising heating the fuel cell stack to permanently bond the anode layer to the anode interconnect or the cathode layer to the cathode interconnect.  
     
     
         35 . The fuel cell stack of  claim 32 , further comprising supplying the reducing gas and an oxidant to each of the fuel cell assembly via individual gas manifolds.  
     
     
         36 . The fuel cell stack of  claim 32 , further comprising testing and inspecting individual fuel cell assemblies for defects.  
     
     
         37 . The fuel cell stack of  claim 36 , wherein testing and inspecting the fuel cell assemblies includes performing a leak test, a resistance measurement test, an impedance measurement test, a mechanical integrity test, an ultrasound test, a X-ray test, an infrared imaging measurement, measurement of open circuit voltage, an impedance spectroscopy or an electrochemical performance test or combinations thereof.