Porous electrode for proton exchange membrane

Abstract

A process for manufacturing a catalytic electrode includes depositing an electrocatalytic ink on a carrier, wherein the electrocatalytic ink includes an electrocatalytic material and a product polymerizable into a protonically conductive polymer. The process also includes solidifying the electrocatalytic ink so as to form an electrode wherein the composition of the product polymerizable into a protonically conductive polymer and its proportion in the ink is defined so that the electrode formed has a breaking strength greater than 1 MPa. The process further includes separating the electrode formed from the carrier.

1 . A process for manufacturing a catalytic electrode comprising the steps of:
 depositing an electrocatalytic ink on a carrier, said electrocatalytic ink including an electrocatalytic material and a product polymerizable into a protonically conductive polymer;   solidifying the electrocatalytic ink so as to form an electrode, the composition of the product polymerizable into a protonically conductive polymer and its proportion in the ink being defined so that the electrode formed has a breaking strength greater than 1 MPa; and   separating the electrode formed from the carrier.   
     
     
         2 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the carrier on which said electrocatalytic ink is deposited has a roughness lower than 5 μm. 
     
     
         3 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the carrier on which said electrocatalytic ink is deposited has an interface energy of between 20 and 60 mN/m. 
     
     
         4 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the electrocatalytic ink deposited has a surface tension higher than an interface energy of the carrier. 
     
     
         5 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the proportion of the product polymerizable into a protonically conductive polymer in the ink is defined so that the electrode formed has a porosity comprised between 20 and 40%. 
     
     
         6 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the electrocatalytic ink deposited comprises methylcellulose in a proportion by weight of between 2 and 10.5% of the solid content of the ink. 
     
     
         7 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the electrocatalytic ink deposited comprises electrocatalytic material in a proportion by weight of between 60 and 75% of a solid content of the ink. 
     
     
         8 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the electrocatalytic ink deposited comprises product polymerizable into a protonically conductive polymer in a proportion by weight of between 20 and 30% of the solid content of the ink. 
     
     
         9 . The manufacturing process as claimed in  claim 1 , in which said separating step is carried out by peeling the electrode formed from the carrier. 
     
     
         10 . A process for manufacturing an electrochemical cell comprising:
 manufacturing a catalytic electrode; and   inserting the catalytic electrode between a proton exchange membrane and a conductive current collector;   wherein manufacturing the catalytic electrode comprises the following steps:
 depositing an electrocatalytic ink on a carrier, said electrocatalytic ink including an electrocatalytic material and a product polymerizable into a protonically conductive polymer; 
 solidifying the electrocatalytic ink so as to form an electrode, the composition of the product polymerizable into a protonically conductive polymer and its proportion in the ink being defined so that the electrode formed has a breaking strength greater than 1 MPa; and 
 separating the electrode formed from the carrier. 
   
     
     
         11 . The manufacturing process as claimed in  claim 11 , comprising a step of holding the catalytic electrode in position by compressing the catalytic electrode between the proton exchange membrane and the current collector. 
     
     
         12 . An electrochemical cell, comprising:
 a proton exchange membrane;   a conductive current collector; and   an electrode inserted between the proton exchange membrane and the current collector, the electrode containing a protonically conductive polymer and an electrocatalytic material, the electrode having a breaking strength greater than 1 MPa and at least 95% of its area not being mechanically bonded to the conductive current collector and not being mechanically bonded to the proton exchange membrane.   
     
     
         13 . Electrochemical cell as claimed in  claim 12 , in which the electrode contains methylcellulose in a proportion by weight of between 2 and 10.5%. 
     
     
         14 . The process for manufacturing a catalytic electrode as claimed in  claim 1 , in which the electrocatalytic ink deposited comprises methylcellulose in a proportion by weight of between 3 and 6% of the solid content of the ink.