Sealing arrangement for fuel cells

Abstract

A sealing arrangement for fuel cells, including a at least one composite ( 40 ) formed of two cell separator plates ( 1, 4 ; BPP) with a deformable membrane electrode assembly ( 18 ; MEA) placed therebetween, the deformable membrane electrode assembly being composed of two porous, gas-permeable plates or layers ( 2, 3 ; GDL) and an ion-exchange membrane ( 5 ; PEM) placed therebetween, the lateral surfaces ( 7, 8, 9 ) of the membrane electrode assembly being set back with respect to the lateral surfaces ( 6, 10 ) of the cell separator plates to leave a sealing gap ( 19 ), an elastic sealing element ( 17 ) which encloses the composite in the manner of a peripheral sealing band ( 28 ), the sealing element ( 17 ) having a peripheral sealing strip ( 20 ) which extends into the sealing gap ( 19 ) to seal the sealing gap ( 19 ) in a gas-tight manner by compression between the cell separator plates ( 1, 4 ; BPP).

1 - 14 . (canceled)  
     
     
         15 . A method for manufacturing a sealing arrangement for a fuel cell or for a stack of fuel cells, comprising the steps of: 
 a) coating or partially impregnating or soaking a marginal region of two porous, gas-permeable plates with a first polymeric sealing material,    b) forming a membrane electrode assembly by joining two porous plates with an ion-exchange membrane place therebetween,    c) forming at least one unit by joining two cell separator plates with the membrane electrode assembly formed in step b) being placed therebetwee,    d) inserting the unit or a stack formed of a plurality of the units into a cavity of an injection mold,    e) pressing the unit or the units in the cavity with a contact pressure until the first polymeric sealing material is capable of withstanding an injection pressure with a second polymeric sealing material,    f) forming a composite or composites by injecting a melt of the second polymeric sealing material into the cavity of the injection mold,    g) solidifying the melt, and    h) removing the composite or the composites of fuel cells formed in f) from the mold.    
     
     
         16 . The method as recited in  claim 15  further comprising further heating or annealing the sealing arrangement.  
     
     
         17 . A method for manufacturing a sealing arrangement for a fuel cell or for a stack of fuel cells comprising the steps of: 
 a) coating or partially impregnating or soaking a marginal region of a deformable membrane electrode assembly with a first polymeric sealing material,    b) forming at least one unit by joining two cell separator plates with the membrane electrode assembly formed in step a) being placed therebetween,    c) inserting the unit of a stack formed of a plurality of the units into a cavity of an injection mold,    d) pressing the second unit or units in the cavity with a contact pressure until the first polymeric sealing material is capable of withstanding an injection pressure with a second polymeric sealing material,    e) forming a composite or composites by injecting a melt of the second polymeric sealing material into the cavity of the injection mold,    f) solidifying the melt, and    g) removing the composite or the composites of fuel cells from the mold.    
     
     
         18 . The method as recited in  claim 17  further comprising further heating or annealing the sealing arrangement.  
     
     
         19 . The method as recited in  claim 17  wherein the coating in step a) is carried out by screen printing.  
     
     
         20 . The method as recited in  19  wherein the screen printing is rotary screen printing.  
     
     
         21 . The method as recited in  claim 17  wherein the coating in step a) is carried out by a high-pressure process or a stamp printing process.  
     
     
         22 . The method as recited in  claim 17  wherein the soaking in step a) is carried out by dipping or by injection molding.  
     
     
         23 . The method as recited in  claim 17  wherein the first or second polymeric material is FPM (fluorocarbon polymer), EPDM (ethylene propylene diene rubber), silicone, PTFE (polytetrafluoroethylene), epoxy resin or TPE (thermoplastic elastomer).  
     
     
         24 . The method as recited in  claim 17  wherein the first and second polymeric materials are the same.  
     
     
         25 . The method as recited in  claim 15  wherein the coating in step a) is carried out by screen printing.  
     
     
         26 . The method as recited in  claim 25  wherein the screen printing is rotary screen printing.  
     
     
         27 . The method as recited in  claim 15  wherein the coating in step a) is carried out by a high-pressure process or a stamp printing process.  
     
     
         28 . The method as recited in  claim 15  wherein the soaking in step a) is carried out by dipping or injection molding.  
     
     
         29 . The method as recited in  claim 15  wherein the first or second polymeric material is FPM (fluorocarbon polymer), EPDM (ethylene propylene diene rubber), silicone, PTFE (polytetrafluoroethylene), epoxy resin or TPE (thermoplastic elastomer).  
     
     
         30 . The method as recited in  claim 15  wherein the first and second polymer materials are the same.