On-demand hydrogen gas generation device having gas management system

Abstract

The present disclosure generally relates to an on-demand hydrogen gas generation device, suitable for use in a fuel cell, which utilizes water electrolysis, and more particularly galvanic cell corrosion, and/or a chemical hydride reaction, to produce hydrogen gas. The present disclosure additionally relates to such a device that comprises a switching mechanism that has an electrical current passing therethrough and that repeatedly and reversibly moves between a first position and a second position when exposed to pressure differential resulting from hydrogen gas generation, in order to (1) alter the rate at which hydrogen gas is generated, such that hydrogen gas is generated on an as-needed basis for a fuel cell connected thereto, and/or (2) ensure a substantially constant flow of hydrogen gas is released therefrom. The present disclosure additionally or alternatively relates to such an on-demand hydrogen gas generation device that comprises a gas management system designed to maximize the release or evolution of hydrogen gas, and in particular dry hydrogen gas, therefrom once it has been formed, thus maximizing hydrogen gas output. The present disclosure is still further directed to a fuel cell comprising such an on-demand hydrogen gas generation device, and in particular a fuel cell designed for small-scale applications.

1 . An on-demand hydrogen gas generation device comprising:
 a switching mechanism for regulating the generation of hydrogen gas within the on-demand hydrogen gas generation device, the switching mechanism being operable in a range of from about 1 psig to about 30 psig; and   a gas management system for transporting hydrogen gas out of the on-demand hydrogen gas generation device, the gas management system comprising an anode, an electrolyte, a gas management electrode comprising a conductive substrate and a catalyst and having a first face and a second face, a gas impermeable and liquid permeable hydrophilic layer, a gas permeable and liquid impermeable hydrophobic layer and a gas exit region, wherein the anode surrounds the gas impermeable and liquid permeable hydrophilic layer, and further wherein the gas impermeable and liquid permeable hydrophilic layer is disposed between the anode and the first face of the gas management electrode, the gas permeable and liquid impermeable hydrophobic layer is disposed on the second face of the gas management electrode and the gas exit region is interior of the gas permeable and liquid impermeable hydrophobic layer.   
   
   
       2 . The on-demand hydrogen gas generation device as set forth in  claim 1  wherein the device is capable of producing an average of at least about 0.1 cubic centimeter/minute/cubic centimeter of fuel volume for a period of time of at least about 1 hour. 
   
   
       3 . The on-demand hydrogen gas generation device as set forth in  claim 2  wherein the device is capable of producing hydrogen having a water content of less than about 1000 ppm water/gram of hydrogen. 
   
   
       4 . The on-demand hydrogen gas generation device as set forth in  claim 3  wherein the conductive substrate is comprised of a material selected from the group consisting of carbon cloth, carbon paper, a non-woven mat material, a metal screen, an expanded metal, and a metal foam. 
   
   
       5 . The on-demand hydrogen gas generation device as set forth in  claim 4  wherein the catalyst includes a metal or a Raney metal of Group VIII. 
   
   
       6 . The on-demand hydrogen gas generation device as set forth in  claim 5  wherein the catalyst includes a metal selected from the group consisting of iron, nickel, nickel power, and Raney nickel. 
   
   
       7 . The on-demand hydrogen gas generation device as set forth in  claim 6  wherein the gas management electrode further includes a material selected from the group consisting of carbon black, graphite, polytetrafluoroethylene, activated carbon, and mixtures thereof. 
   
   
       8 . The on-demand hydrogen gas generation device as set forth in  claim 7  wherein the anode includes a metal selected from the group consisting of zinc, aluminum, magnesium, and titanium. 
   
   
       9 . The on-demand hydrogen gas generation device as set forth in  claim 8  wherein the anode further includes an alloying agent selected from the group consisting of indium, bismuth, tin, calcium, aluminum, lead, and combinations thereof. 
   
   
       10 . The on-demand hydrogen gas generation device as set forth in  claim 1  wherein the device is orientation independent. 
   
   
       11 . The on-demand hydrogen gas generation device as set forth in  claim 1  wherein the gas management electrode, gas impermeable and liquid permeable layer, and gas permeable and liquid impermeable layer are a single integral component. 
   
   
       12 . The on-demand hydrogen gas generation device as set forth in  claim 1  wherein the device further includes a porous separator disposed between the anode and the gas impermeable and liquid permeable layer. 
   
   
       13 . An on-demand hydrogen gas generation device comprising:
 a switching mechanism for regulating the generation of hydrogen gas within the on-demand hydrogen gas generation device, the switching mechanism being operable in a range of from about 1 psig to about 30 psig; and   a circular gas management system for transporting hydrogen gas out of the on-demand hydrogen gas generation device, the gas management system comprising an anode, an electrolyte, a gas management electrode comprising a conductive substrate and a catalyst and having a first face and a second face, a gas impermeable and liquid permeable hydrophilic layer, a gas permeable and liquid impermeable hydrophobic layer, wherein the gas impermeable and liquid permeable layer substantially surrounds the anode, the gas management electrode surrounds the gas impermeable and liquid permeable hydrophobic layer, and wherein the gas permeable and liquid impermeable layer surrounds the gas management electrode.   
   
   
       14 . The on-demand hydrogen gas generation device as set forth in  claim 13  wherein the device is capable of producing about an average of at least about 0.1 cubic centimeter/minute/cubic centimeter of fuel volume for a period of time of at least about 1 hour. 
   
   
       15 . The on-demand hydrogen gas generation device as set forth in  claim 14  wherein the device is capable of producing hydrogen having a water content of less than about 1000 ppm water/gram of hydrogen. 
   
   
       16 . The on-demand hydrogen gas generation device as set forth in  claim 15  wherein the conductive substrate is comprised of a material selected from the group consisting of carbon cloth, carbon paper, a non-woven mat material, a metal screen, an expanded metal, and a metal foam. 
   
   
       17 . The on-demand hydrogen gas generation device as set forth in  claim 16  wherein the catalyst includes a metal or Raney metal from Group VIII. 
   
   
       18 . The on-demand hydrogen gas generation device as set forth in  claim 17  wherein the catalyst includes a metal selected from the group consisting of iron, nickel, nickel powder, and Raney nickel. 
   
   
       19 . The on-demand hydrogen gas generation device as set forth in  claim 13  wherein the device is orientation independent. 
   
   
       20 . The on-demand hydrogen gas generation device as set forth in  claim 13  wherein the gas management electrode, gas impermeable and liquid permeable layer, and gas permeable and liquid impermeable layer are a single integrated component. 
   
   
       21 . The on-demand hydrogen gas generation device as set forth in  claim 13  wherein the device additionally includes a porous separator disposed between the anode and the gas impermeable and liquid permeable layer. 
   
   
       22 . An on-demand hydrogen gas generation device comprising:
 a switching mechanism for regulating the generation of hydrogen gas within the on-demand hydrogen gas generation device, the switching mechanism being operable in a range of from about 1 psig to about 30 psig; and   a gas management system for transporting hydrogen gas out of the on-demand hydrogen gas generation device, the gas management system comprising an anode, an electrolyte, a gas management electrode comprising a conductive substrate and a catalyst and having a first face and a second face, wherein the first face comprises a gas impermeable and liquid permeable hydrophilic layer and the second face comprises a gas permeable and liquid impermeable hydrophobic layer, and a gas exit region, wherein the first face is adjacent the anode and wherein the gas exit region is positioned interior of the gas permeable and liquid impermeable layer.   
   
   
       23 . The on-demand hydrogen gas generation device as set forth in  claim 22  wherein the device is capable of producing an average flow of hydrogen gas of at least about 0.1 cubic centimeter/minute/cubic centimeter of fuel volume for a period of time of at least about 1 hour. 
   
   
       24 . The on-demand hydrogen gas generation device as set forth in  claim 23  wherein the device is capable of producing hydrogen having a water content of less than about 1000 ppm water/gram of hydrogen. 
   
   
       25 . The on-demand hydrogen gas generation device as set forth in  claim 23  wherein the conductive substrate is selected from a material from the group consisting of carbon cloth, carbon paper, a non-woven mat material, a metal screen, an expanded metal, and a metal foam. 
   
   
       26 . The on-demand hydrogen gas generation device as set forth in  claim 25  wherein the catalyst includes a metal or Raney metal of Group VIII. 
   
   
       27 . The on-demand hydrogen gas generation device as set forth in  claim 25  wherein the catalyst includes a metal selected from the group consisting of iron, nickel, nickel powder, and Raney nickel. 
   
   
       28 . The on-demand hydrogen gas generation device as set forth in  claim 22  wherein the device is orientation independent. 
   
   
       29 . The on-demand hydrogen gas generation device as set forth in  claim 22  wherein the gas management electrode, gas impermeable and liquid permeable layer, and gas permeable and liquid impermeable layer are a single integrated component. 
   
   
       30 . The on-demand gas generation device as set forth in  claim 22  wherein the device further includes a porous separator disposed between the anode and the gas impermeable and liquid permeable layer.