Robust voltage management in electrochemical hydrogen cells

Abstract

Apparatus and operating methods are provided for integrated electrochemical hydrogen separation and compression systems. In one possible embodiment, an electrical potential is provided across an electrochemical cell. A portion of the potential is shunted to an electrical load when the potential is higher than a predetermined threshold. As an example, a Zener diode can be used as a suitable shunting mechanism. The invention can be used with individual cells or stacks of cells. Various methods, features and system configurations are discussed.

1 . A method of managing voltage across an electrochemical cell, comprising:
 providing an electrical potential across an electrochemical cell; and   shunting a portion of the potential to an electrical load when the potential is higher than a predetermined threshold.   
     
     
         2 . The method of  claim 1 , wherein the cell is a hydrogen pumping cell. 
     
     
         3 . The method of  claim 1 , wherein the cell has an anode in contact with hydrogen, and a cathode in contact with hydrogen. 
     
     
         4 . The method of  claim 1 , wherein the potential is shunted to the electrical load through a diode. 
     
     
         5 . The method of  claim 1 , wherein the potential is shunted to the electrical load through a Zener diode. 
     
     
         6 . The method of  claim 1 , wherein the electrical load is an electrical grounding circuit. 
     
     
         7 . The method of  claim 1 , wherein the electrical load is an second electrochemical cell. 
     
     
         8 . The method of  claim 1 , wherein the predetermined threshold is 0.6 volts. 
     
     
         9 . The method of  claim 1 , wherein the predetermined threshold is 0.8 volts. 
     
     
         10 . The method of  claim 1 , wherein the cell forms part of a stack of cells electrically connected in series. 
     
     
         11 . A method of managing voltage across an electrochemical cell, comprising:
 providing an electrical potential across a first electrochemical cell and a second electrochemical cell, wherein the first cell and second cell are electrically connected in series;   connecting a diode in an electrically parallel configuration with the first and second cells; and   shunting a portion of the potential through the diode to an electrical load when the potential is higher than a predetermined threshold.   
     
     
         12 . The method of  claim 11 , wherein the cell is a hydrogen pumping cell. 
     
     
         13 . The method of  claim 11 , wherein the cell has an anode in contact with hydrogen, and a cathode in contact with hydrogen. 
     
     
         14 . The method of  claim 11 , wherein the diode is a Zener diode. 
     
     
         15 . The method of  claim 11 , wherein the electrical load is an electrical grounding circuit. 
     
     
         16 . The method of  claim 11 , wherein the electrical load is an second electrochemical cell. 
     
     
         17 . The method of  claim 11 , wherein the predetermined threshold is 0.6 volts. 
     
     
         18 . The method of  claim 11 , wherein the predetermined threshold is 0.8 volts. 
     
     
         19 . The method of  claim 11 , wherein the cell forms part of a stack of cells electrically connected in series. 
     
     
         20 . A voltage management system for electrochemical cells, comprising:
 an electrochemical cell;   a power supply adapted to provide an electrical potential across the electrochemical cell; and   a shunting mechanism adapted to shunt a portion of the potential to an electrical load when the potential is higher than a predetermined threshold.   
     
     
         21 . The system of  claim 20 , wherein the cell is a hydrogen pumping cell. 
     
     
         22 . The system of  claim 20 , wherein the cell has an anode in contact with hydrogen, and a cathode in contact with hydrogen. 
     
     
         23 . The system of  claim 20 , wherein the shunting mechanism is a diode that is electrically connected in parallel to the cell. 
     
     
         24 . The system of  claim 20 , wherein the shunting mechanism is a Zener diode that is electrically connected in parallel to the cell. 
     
     
         25 . The system of  claim 20 , wherein the electrical load is an electrical grounding circuit. 
     
     
         26 . The system of  claim 20 , wherein the electrical load is an second electrochemical cell. 
     
     
         27 . The system of  claim 20 , wherein the predetermined threshold is 0.6 volts. 
     
     
         28 . The system of  claim 20 , wherein the predetermined threshold is 0.8 volts. 
     
     
         29 . The system of  claim 20 , wherein the power supply has a potential limit that is higher than the predetermined threshold. 
     
     
         30 . The system of  claim 20 , wherein the cell forms part of a stack of cells electrically connected in series.