Composite three-dimensional electrodes and methods of fabrication

Abstract

Disclosed are gas permeable 3D electrodes, preferably that have practical utility in, particularly, electro-energy and electro-synthetic applications. Gas permeable materials, such as non-conductive porous polymer membranes, are attached to one or more porous conductive materials. In another aspect there is provided a method for the fabrication of gas permeable 3D electrodes, for example gas diffusion electrodes (GDEs). The 3D electrodes can be utilised in electrochemical cells or devices.

1 . A method of fabricating a gas permeable 3D electrode, comprising the steps of:
 selecting a gas permeable material layer that is non-conductive; and   attaching a porous conductive material layer to a first side of the gas permeable material layer using a binder material;   wherein the binder material penetrates the porous conductive material layer.   
     
     
         2 . The method of  claim 1 , further comprising laminating the porous conductive material layer to the gas permeable material layer together. 
     
     
         3 . The method of  claim 2 , wherein the laminating comprises compressing the porous conductive material layer and the gas permeable material layer together under pressure and heat. 
     
     
         4 . The method of  claim 1 , further comprising applying the binder material onto a surface of the gas permeable material layer or the porous conductive material layer, placing the porous conductive material layer over the binder material coating, and compressing the gas permeable material layer and the porous conductive material layer together. 
     
     
         5 . The method of  claim 4 , wherein the applying the binder material comprises screen printing the binder material onto the gas permeable material layer or the porous conductive material layer. 
     
     
         6 . The method of  claim 4 , wherein the applying the binder material comprises painting the binder material onto the gas permeable material layer or the porous conductive material layer. 
     
     
         7 . The method of  claim 4 , wherein the applying the binder material comprises spraying the binder material onto the gas permeable material layer or the porous conductive material layer. 
     
     
         8 . The method of  claim 1 , further comprising attaching a second porous conductive material layer to a second side of the gas permeable material layer using a binder material, wherein the second side of the gas permeable material layer is opposite the first side of the gas permeable material layer. 
     
     
         9 . The method of  claim 1 , wherein the gas permeable material layer and the porous conductive material layer are provided as separate sheets. 
     
     
         10 . The method of  claim 1 , wherein the gas permeable material layer is a polymer layer. 
     
     
         11 . The method of  claim 10 , wherein the gas permeable material layer is a porous hydrophobic polymer membrane. 
     
     
         12 . The method of  claim 1 , wherein the gas permeable material layer is impermeable to an alkaline liquid electrolyte. 
     
     
         13 . The method of  claim 1 , wherein a boundary region separates the porous conductive material layer from the gas permeable material layer. 
     
     
         14 . The method of  claim 1 , wherein the gas permeable material layer is an expanded polytetrafluoroethylene (ePTFE) membrane. 
     
     
         15 . The method of  claim 1 , wherein the porous conductive material layer is a metallic mesh. 
     
     
         16 . The method of  claim 1 , wherein the binder material is a mixture comprising a binder component and a catalyst component. 
     
     
         17 . The method of  claim 1 , wherein the porous conductive material and the binder material together comprise less than or equal to 30% carbon atoms. 
     
     
         18 . The method of  claim 17 , wherein the porous conductive material and the binder material together comprise less than or equal to 10% carbon atoms. 
     
     
         19 . The method of  claim 1 , wherein the binder material comprises a sulfonated tetrafluoroethylene-based fluoropolymer copolymer in an amount from 1% to 30% by weight. 
     
     
         20 . The method of  claim 1 , wherein the binder material forms a layer 1 micron to 100 microns thick.