In-Situ Anode Activation By A Cathode In An Alkaline Water Electrolytic Cell

Abstract

An electrolytic cell for alkaline water electrolysis with in-situ anode activation comprising: an anode; a cathode wherein at least a part of a surface of the cathode comprises an electrically conducting stable material and an anode catalytic material adapted to be released from the surface of the cathode in alkaline water and be deposited at a surface of the anode when an electric voltage is applied across the anode and the cathode; and a diaphragm separating the anode and the cathode, wherein the diaphragm is gas tight and is permeable to the anode catalytic material.

What is claimed is: 
     
         1 . An electrolytic cell for alkaline water electrolysis with in-situ anode activation, the electrolytic cell comprising:
 an anode;   a cathode wherein at least a part of a surface of the cathode comprises an electrically conducting stable material and an anode catalytic material adapted to be released from the surface of the cathode in alkaline water and be deposited at a surface of the anode when an electric voltage is applied across the anode and the cathode; and   a diaphragm separating the anode and the cathode, wherein the diaphragm is gas tight and is permeable to the anode catalytic material.   
     
     
         2 . The electrolytic cell according to  claim 1 , wherein the electrically conducting stable material comprises Nickel. 
     
     
         3 . The electrolytic cell according to  claim 1 , wherein the anode catalytic material comprises at least one of Cobalt, Manganese, Molybdenum, Chromium, and a combination thereof. 
     
     
         4 . The electrolytic cell according to  claim 1 , wherein the anode catalytic material comprises between 4 percentage and 30 percentage by mass of the cathode. 
     
     
         5 . The electrolytic cell according to  claim 1 , wherein the at least part of the surface of the cathode further comprises Sulfur. 
     
     
         6 . The electrolytic cell according to  claim 1 , wherein the anode consists of Nickel. 
     
     
         7 . A method for in-situ anode activation of an anode positioned in an electrolytic cell for alkaline water electrolysis, the method comprising:
 providing a cathode wherein at least a part of a surface of the cathode comprises an electrically conducting stable material and an anode catalytic material, the anode catalytic material adapted to be released from the cathode in alkaline water;   releasing anode catalytic material from the cathode into an electrolyte in the electrolytic cell by positioning the cathode in the electrolytic cell such the at least a part of the surface of the cathode is in contact with the electrolyte;   wherein the electrolyte comprises alkaline water;   the cathode is separated from the anode in the electrolytic cell by a gas tight diaphragm permeable to the anode catalytic material; and   depositing at least a part of the anode catalytic material so released surface of the anode by applying an electric voltage across the anode and the cathode to reduce an overpotential at the anode.   
     
     
         8 . The method according to  claim 7 , wherein releasing the anode catalytic material from the cathode into the electrolyte takes place at an open circuit potential of the electrolytic cell. 
     
     
         9 . The method according to  claim 7 , further comprising an additional release of the anode catalytic material from the cathode at least a part of the anode catalytic material is released from the cathode into the electrolyte while applying the external electric voltage across the anode and the cathode. 
     
     
         10 . The method according to  claim 9 , wherein the external electric voltage applied across the across the anode and the cathode corresponds to a pH of the electrolyte and a molality of the anode catalytic material present in the electrolyte. 
     
     
         11 . The method according to  claim 7 , wherein the electrically conducting stable material comprises Nickel. 
     
     
         12 . The method according to  claim 7 , wherein the anode catalytic material comprises at least one of Cobalt, Manganese, Molybdenum, Chromium, and a combination thereof. 
     
     
         13 . The method according to  claim 12 , wherein the anode catalytic material in the cathode comprises between 4 percentage and 30 percentage by mass of the cathode. 
     
     
         14 . The method according to  claim 7 , wherein the at least a part of the surface of the cathode further comprises Sulfur. 
     
     
         15 . The method according to  claim 7 , wherein the anode consists of Nickel. 
     
     
         16 . The electrolytic cell according to  claim 1 , wherein the anode catalytic material comprises between 10 percentage and 15 percentage by mass of the cathode. 
     
     
         17 . The method according to  claim 12 , wherein the anode catalytic material in the cathode comprises between 10 percentage and 15 percentage by mass of the cathode.