Oxygen regulated fuel cell

Abstract

A device includes a container having a top plate containing an array of oxygen limiting pinholes and a chamber to hold a chemical hydride fuel, a fuel cell proton exchange membrane electrode assembly supported within the container between the top plate and the chamber, a first gas diffusion layer supported between the fuel cell proton exchange membrane electrode assembly and the top plate, and a second gas diffusion layer supported between the fuel cell proton exchange membrane electrode assembly and the chamber.

1 . A device comprising:
 a container having a top plate containing an array of oxygen limiting pinholes and a chamber to hold a chemical hydride fuel;   a fuel cell proton exchange membrane electrode assembly supported within the container between the top plate and the chamber; and   a second gas diffusion layer supported between the fuel cell proton exchange membrane electrode assembly and the chamber.   
     
     
         2 . The device of  claim 1  wherein the array of oxygen limiting pinholes are sized to limit oxygen supplied to a cathode of the fuel cell proton exchange membrane electrode assembly. 
     
     
         3 . The device of  claim 2  wherein the oxygen limiting pinholes have a size corresponding to an average power of a selected load. 
     
     
         4 . The device of  claim 3  wherein the oxygen limiting pinholes are coupled to ambient atmosphere to obtain exposure to oxygen and water vapor and wherein the oxygen limiting pinholes restrict water vapor recovered from ambient atmosphere such that oxygen is the primary regulator of electricity generated by the fuel cell proton exchange membrane. 
     
     
         5 . The device of  claim 1  wherein the oxygen limiting pinholes are configured to regulate oxygen provided to a cathode of the fuel cell proton exchange membrane electrode assembly to control electricity generated without regulation of water vapor. 
     
     
         6 . The device of  claim 1  and further comprising a perforated support plate supported by the container between the second diffusion layer and the bottom chamber. 
     
     
         7 . The device of  claim 1  and further comprising a hydrogen pressure relief valve supported by the container in the chamber. 
     
     
         8 . The device of  claim 1  wherein the chamber comprises a chemical hydride fuel separated from the fuel cell proton exchange membrane electrode assembly by a particulate filter. 
     
     
         9 . The device of  claim 1  wherein the fuel cell proton exchange membrane electrode assembly comprises an anode layer adjacent the second gas diffusion layer and a cathode layer adjacent the first gas diffusion layer. 
     
     
         10 . The device of  claim 1  wherein the fuel cell proton exchange membrane electrode assembly comprises a cathode layer adjacent the first gas diffusion layer such that the pin holes provide a limited supply of oxygen to the cathode layer through the first gas diffusion layer. 
     
     
         11 . A device comprising:
 a container having a top plate containing an array of oxygen limiting pinholes and a chamber to hold a chemical hydride fuel;   a pressure relief valve fluidly connected to the container; and   a fuel cell membrane electrode assembly supported within the container between the top plate and the chamber positioned to receive oxygen from the pinholes and hydrogen from the chamber.   
     
     
         12 . The device of  claim 11  wherein the array of oxygen limiting pinholes are sized to limit oxygen supplied to a cathode of the fuel cell membrane electrode assembly. 
     
     
         13 . The device of  claim 12  wherein the oxygen limiting pinholes have a size corresponding to an average power of a selected load. 
     
     
         14 . The device of  claim 13  wherein the oxygen limiting pinholes are coupled to ambient atmosphere to obtain exposure to oxygen and water vapor and wherein the oxygen limiting pinholes restrict water vapor recovered from ambient atmosphere such that oxygen is the primary regulator of electricity generated by the fuel cell membrane electrode assembly. 
     
     
         15 . The device of  claim 11  wherein the oxygen limiting pinholes are configured to regulate oxygen provided to a cathode of the membrane electrode assembly to control electricity generated without regulation of water vapor. 
     
     
         16 . The device of  claim 11  wherein the chamber comprises a chemical hydride fuel separated from the membrane electrode assembly by a particulate filter. 
     
     
         17 . The device of  claim 11  wherein the membrane electrode assembly comprises a cathode layer adjacent the pin holes that provide a limited supply of oxygen to the cathode layer through the first gas diffusion layer. 
     
     
         18 . A method comprising:
 exposing a cathode of a fuel cell membrane electrode assembly to a limited supply of oxygen via one or more pinholes in a power generator container;   providing hydrogen to an anode of the fuel cell membrane electrode assembly from a chamber containing a chemical hydride;   reacting the oxygen and hydrogen to produce electricity and water vapor; and   providing water vapor to the chemical hydride to cause the chemical hydride to generate more hydrogen.   
     
     
         19 . The method of  claim 18  wherein the one or more pinholes are dimensioned to provide an amount of oxygen to cause the fuel cell membrane electrode assembly to provide a selected average energy for consumption by a load. 
     
     
         20 . The method of  claim 18  and further comprising relieving excess hydrogen pressure in the chamber via a relief valve.