Apparatus and method for maintaining compression of the active area in an electrochemical cell

Abstract

An electrochemical cell includes a first electrode, a second electrode, a proton exchange membrane disposed between and in intimate contact with the electrodes, and a pressure pad disposed in electrical communication with the first electrode. The pressure pad is an electrically conductive sheet and is of a structure that is conformable to pressure variations within the cell. Methods of forming the pressure pad include disposing dimples or corrugations at the electrically conductive member. A method of maintaining compression within the cell includes disposing the electrically conductive member and the compression member at the first electrode, applying a load at the cell to compress the cell components, and maintaining electrical communication through the electrically conductive member.

1 . An electrically-conductive compression pad suitable for use in an electrolysis cell stack, said electrically-conductive compression pad comprising: 
 a single sheet of electrically-conductive material, said single sheet of electrically-conductive material having a top surface and a bottom surface, said single sheet of electrically-conductive material being bent up and down to include a plurality of alternating ribs and channels; and    elastomeric material mounted within said channels, said elastomeric material being dimensioned so that, when said elastomeric material is compressed, a top surface of said elastomeric material lies planar with said ribs and exerts substantially uniform pressure across each of said top surface and said bottom surface of said single sheet.    
   
   
       2 . The electrically-conductive compression pad as claimed in  claim 1  wherein said alternating ribs and channels are linear and parallel to one another.  
   
   
       3 . The electrically-conductive compression pad as claimed in  claim 1  wherein said single sheet of electrically-conductive material is a sheet of metal.  
   
   
       4 . The electrically-conductive compression pad as claimed in  claim 3  wherein said metal is selected from the group consisting of niobium, titanium, zirconium, tantalum, copper, nickel, steel and hastelloys.  
   
   
       5 . The electrically-conductive compression pad as claimed in  claim 3  wherein said metal is niobium.  
   
   
       6 . The electrically-conductive compression pad as claimed in  claim 1  wherein said elastomeric material is a rubber.  
   
   
       7 . The electrically-conductive compression pad as claimed in  claim 1  wherein said elastomeric material is a silicone.  
   
   
       8 . The electrically-conductive compression pad as claimed in  claim 1  wherein said single sheet of electrically-conductive material is circular in shape.  
   
   
       9 . The electrically-conductive compression pad as claimed in  claim 1  wherein said single sheet of electrically-conductive material is rectangular in shape.  
   
   
       10 . An electrically-conductive compression pad suitable for use in an electrolysis cell stack, said electrically-conductive compression pad comprising: 
 a single sheet of electrically-conductive material, said single sheet of electrically-conductive material having a top surface and a bottom surface, said single sheet of electrically-conductive material having a plurality of raised portions; and    a plurality of members arranged between and sized to fit between said plurality of raised portions so that the top surface of each of said members is below the top of the raised portion when no pressure is applied to said single sheet of electrically-conductive material.    
   
   
       11 . The electrically conductive compression pad of  claim 10  wherein said single sheet of electrically-conductive material is a corrugated sheet and said plurality of raised portions are parallel to each other.  
   
   
       12 . The electrically conductive compression pad of  claim 11  wherein a depressed area is formed between said raised portions and said members is a molten elastomeric material deposited within said depressed area.  
   
   
       13 . The electrically-conductive compression pad as claimed in  claim 11  wherein said elastomeric material is deposited by injection molding.  
   
   
       14 . An electrically-conductive compression pad suitable for use in an electrolysis cell stack, said electrically-conductive compression pad comprising: 
 a single sheet of electrically-conductive material, said single sheet of electrically-conductive material having a top surface and a bottom surface, said single sheet of electrically-conductive material being corrugated to include a plurality of alternating ribs and channels, said single sheet of electrically-conductive material having a compressed position and an uncompressed position; and    elastomeric material mounted within said channels, said elastomeric material having a top surface being substantially parallel to said single sheet of electrically-conductive material, wherein and said elastomeric material is sized to fit within said channels so that when said single sheet of electrically conductive material is in said uncompressed position, said elastomeric material top surface is offset from a top surface of said ribs.    
   
   
       15 . The electrically conductive compression pad of  claim 14  wherein said elastomeric material is arranged so that when said single sheet of electrically conductive material is in said compressed position, said top surface of said elastomeric material is substantially planar with said top surface of said ribs.  
   
   
       16 . The electrically conductive compression pad of  claim 15  wherein said elastomeric material exerts substantially uniform pressure across each of said top surface and said bottom surface of said single sheet.  
   
   
       17 . The electrically conductive compression pad of  claim 16  wherein said elastomeric material is electrically conductive.  
   
   
       18 . The electrically conductive compression pad of  claim 17  wherein said electrically conductive elastomeric material includes nonconductive particles coated with conductive materials.  
   
   
       19 . The electrically conductive compression pad of  claim 16  wherein said single sheet of electrically-conductive material is made from a metal.  
   
   
       20 . The electrically conductive compression pad of  claim 19  wherein said metal is selected from the group consisting of niobium, titanium, zirconium, tantalum, copper, nickel, steel and hastelloys.