Manufacture of electrical energy generation equipment

Abstract

The invention relates to a portable electrical energy generator, its components, and manufacture of the components and generator. The generator includes a bi-polar plate stack, which is well suited for use in a fuel cell. The stack may include at least one spacer that limits compression of a membrane electrode assembly in the fuel cell. The stack may also include a polymer binder that holds the stack together and/or maintains a compression force on the membrane electrode assembly. An open cathode manifold may also provided to ease oxygen movement. High throughput and low cost manufacture of bi-polar plates is also described herein.

1 . A stack for use in an electrical energy generator, the stack comprising:
 a first bi-polar plate including a) a substrate, and b) a channel field formed into the substrate and located in a central portion of the bi-polar plate;   a second bi-polar plate including a) a substrate, and b) a second channel field formed into the second bi-polar plate substrate and located in a central portion of the second bi-polar plate;   at least one spacer attached to perimeter portion of the first bi-polar plate and attached to perimeter portion of the second bi-polar plate, wherein the at least one spacer is configured to form a socket between the first bi-polar plate and the second bi-polar plate; and   a membrane electrode assembly disposed in the socket.   
     
     
         2 . The stack of  claim 1 , wherein the at least one spacer is configured to produce a socket depth between the first bi-polar plate and the second bi-polar plate that is less than a thickness for the membrane electrode assembly before assembly of the stack. 
     
     
         3 . The stack of  claim 2 , wherein stack is compressed after assembly of the stack and the at least one spacer is sized to limit compression of the membrane electrode assembly. 
     
     
         4 . The stack of  claim 2 , wherein the socket depth is between about 0.7 and about 0.9 times the thickness for the membrane electrode assembly before assembly of the bi-polar plate stack. 
     
     
         5 . The stack of  claim 4 , wherein the socket depth is between about 0.75 and about 0.85 times the thickness for the membrane electrode assembly before assembly of the bi-polar plate stack. 
     
     
         6 . The stack of  claim 4 , wherein the first bi-polar plate includes a central thickness between a first surface of the substrate and an opposite surface of the substrate in the central portion that is about the same thickness between the first surface and the opposite surface in the perimeter portion. 
     
     
         7 . The stack of  claim 1 , wherein the first bi-polar plate includes a) a first sheet with the first bi-polar plate channel field formed through the first sheet and b) a second sheet attached to the first sheet and including a second channel field formed through the second sheet. 
     
     
         8 . The stack of  claim 1 , wherein the spacer has a smaller planar area than the first bi-polar plate. 
     
     
         9 . The stack of  claim 8 , wherein the spacer has a larger cross sectional area for a planar feature than a planar feature on the first bi-polar plate. 
     
     
         10 . The stack of  claim 9 , wherein the spacer and the first bi-polar plate both include a metal and are joined using a fillet weld. 
     
     
         11 . The stack of  claim 1 , wherein the first bi-polar plate is attached to the spacer using an adhesive hydraulic sealant. 
     
     
         12 . The stack of  claim 1 , wherein each of the first and second bi-polar plates is formed from a single substantially flat substrate and includes channel fields on opposite surfaces of the substrate. 
     
     
         13 . The stack of  claim 12 , wherein channels of the channel fields are formed as troughs into opposite surfaces of the substrate. 
     
     
         14 . A stack for use in an electrical energy generator, the stack comprising:
 a first bi-polar plate formed of a single substantially flat substrate having a first channel field formed into the first bi-polar plate substrate and located in a central portion of the first bi-polar plate;   a second bi-polar plate formed of a single substantially flat substrate having a second channel field formed into the second bi-polar plate substrate and located in a central portion of the second bi-polar plate;   at least one spacer attached to perimeter portion of the first bi-polar plate and attached to perimeter portion of the second bi-polar plate, wherein the at least one spacer is configured to form a socket between the first bi-polar plate and the second bi-polar plate; and   a membrane electrode assembly disposed in the socket.   
     
     
         15 . The stack of  claim 14 , wherein the at least one spacer is configured to produce a socket depth between the bi-polar plates that is less than a thickness for the membrane electrode assembly before assembly of the stack. 
     
     
         16 . The stack of  claim 15 , wherein the socket depth is between about 0.7 and about 0.9 times a thickness of the membrane electrode assembly before assembly of the stack. 
     
     
         17 . The stack of  claim 14 , wherein the at least one spacer is attached to the bi-polar plates using an adhesive hydraulic sealant. 
     
     
         18 . The stack of  claim 14 , wherein the spacers comprise a rigid material with an elastic modulus large enough to prevent further compression on the membrane electrode assembly once the stack is assembled. 
     
     
         19 . The stack of  claim 18 , wherein the elastic modulus is greater than about 1 GPa. 
     
     
         20 . The stack of claim of  claim 14 , wherein the spacers comprise a material selected from the group consisting of a metal, polymer, and ceramic.