Electrochemical cell

Abstract

The present invention describes an electrochemical cell, comprising at least an anode half-cell with an anode, a cathode half-cell with a cathode, and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode is a gas diffusion electrode. And a gap is provided between the gas diffusion electrode and the ion exchange membrane, and the half-cell with the gas diffusion electrode has an electrolyte feed and an electrolyte discharge as well as a gas inlet and a gas outlet. The electrochemical cell preferably has an electrolyte feed that is hermetically connected to the gap.

1 - 20 . (canceled) 
     
     
         21 . An electrochemical cell, comprising:
 an anode half-cell comprising an anode,   a cathode half-cell comprising a cathode,   an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode being a gas diffusion electrode, and   a gap arranged between the gas diffusion electrode and the ion exchange membrane,   wherein the half-cell with the gas diffusion electrode has an electrolyte feed, an electrolyte discharge, a gas inlet, and a gas outlet, and   wherein the electrolyte feed is directly and hermetically connected to the gap.   
     
     
         22 . An electrochemical cell according to  claim 21 , further comprising flow guides arranged in the gap. 
     
     
         23 . An electrochemical cell according to  claim 22 , wherein the flow guides are clamped between the gas diffusion electrode and the ion exchange membrane. 
     
     
         24 . An electrochemical cell according to  claim 22 , wherein the flow guides are inclined with respect to horizontal. 
     
     
         25 . A method for the electrolysis of an aqueous alkali metal halide solution in an electrochemical cell, said cell comprising:
 an anode half-cell comprising an anode,   a cathode half-cell comprising a cathode,   an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, wherein the anode and/or the cathode comprise a gas diffusion electrode, and   a gap arranged between the gas diffusion electrode and the ion exchange membrane,   wherein the half-cell having a gas diffusion electrode has an electrolyte feed, an electrolyte discharge, a gas inlet, and a gas outlet, and   wherein said electrolyte feed is directly and hermetically connected to said gap, said method comprising:   allowing electrolyte to flow from a top portion of said cell downward in the gap by a pump, and wherein the gap is completely filled with electrolyte.   
     
     
         26 . A method according to  claim 25 , wherein flow guide structures are arranged in the gap. 
     
     
         27 . An electrochemical cell comprising a gas diffusion electrode, an ion exchange means, a gap provided therebetween, an electrolyte feed, wherein said electrolyte feed is directly and hermetically connected to said gap, and at least one flow guide provided in said gap wherein said at least one flow guide is capable of causing liquid flowing through said gap to flow at a velocity less than free fall. 
     
     
         28 . A cell of  claim 27  wherein multiple flow guides are provided, each flow guide having an opening and the cross sectional area of each opening of each said flow guide is substantially the same. 
     
     
         29 . An electrochemical cell comprising a gas diffusion electrode, an ion exchange means, a gap therebetween, and a liquid supply means directly and hermetically connected to said gap. 
     
     
         30 . A method for reducing the flow velocity of electrolyte in an electrochemical cell comprising a gas diffusion electrode, an ion exchange means, a gap therebetween, and an electrolyte feed directly and hermetically connected to said gap, said method comprising (i) employing at least one flow guide with an opening having a selected cross-sectional area designed to permit the velocity of electrolyte flowing therethrough to be less than free fall and/or (ii) adjusting said velocity via a pump. 
     
     
         31 . An electrochemical cell according to  claim 28 , wherein the flow guides are inclined with respect to horizontal. 
     
     
         32 . A cell of  claim 27 , wherein said ion exchange means comprises an ion exchange membrane. 
     
     
         33 . A cell of  claim 27  that is substantially free of hydrophilic porous material in said gap. 
     
     
         34 . A cell of  claim 29  that is substantially free of hydrophilic porous material in said gap. 
     
     
         35 . A cell of  claim 27 , wherein said flow guide is curved. 
     
     
         36 . A cell of  claim 28 , wherein said openings are round or angular.