Electrode for fuel cell and method of producing the same

Abstract

A method of producing an electrode having a high performance in a simple and convenient manner which does not require the use of any of the medium, surfactant and pore-producing agent is disclosed. In the disclosed method, a layer including a catalyst powder is formed on a surface of a polymer electrolyte film or a porous conductive electrode substrate by supplying an electrostatically-charged catalyst powder to the polymer electrolyte film or the porous conductive electrode substrate. Alternatively, a layer including a catalyst powder is formed on a surface of a polymer electrolyte film or a porous conductive electrode substrate by spraying the catalyst powder on the surface of the polymer electrolyte film or the porous conductive electrode substrate together with a carrier gas, thereby to cause the catalyst powder to adhere to the surface.

1 . A method of producing an electrode for a fuel cell comprising the step of supplying an electrostatically-charged catalyst powder onto a surface of a polymer electrolyte film or a porous conductive electrode substrate to form a layer including the catalyst powder on said polymer electrolyte film or said porous conductive electrode substrate.  
     
     
         2 . The method of producing an electrode for a fuel cell in accordance with  claim 1 , wherein said polymer electrolyte film or said porous conductive electrode substrate is grounded, and wherein said catalyst powder is adsorbed on the surface of said polymer electrolyte film or said porous conductive electrode substrate by an electrostatic force which works between the both.  
     
     
         3 . The method of producing an electrode for a fuel cell in accordance with  claim 1 , wherein said catalyst powder includes a carbon fine powder carrying a noble metal.  
     
     
         4 . The method of producing an electrode for a fuel cell in accordance with  claim 3 , wherein said catalyst powder contains a polymer electrolyte.  
     
     
         5 . The method of producing an electrode for a fuel cell in accordance with  claim 4 , wherein said catalyst powder further includes a carbon fine powder coated with a fluorocarbon resin.  
     
     
         6 . The method of producing an electrode for a fuel cell in accordance with  claim 1 , wherein said catalyst powder has been prepared by mixing a carbon fine powder carrying a noble metal with a colloidal dispersion of a polymer electrolyte and then drying the mixture.  
     
     
         7 . The method of producing an electrode for a fuel cell in accordance with  claim 1 , further comprising the step of adhering said polymer electrolyte film on the layer including said catalyst powder by heating.  
     
     
         8 . The method of producing an electrode for a fuel cell in accordance with  claim 7 , further comprising, in advance to the step of adhering said polymer electrolyte film on the layer including said catalyst powder, the step of applying a polymer electrolyte solution on the surface of said polymer electrolyte film and then drying.  
     
     
         9 . A method of producing an electrode for a fuel cell comprising the step of spraying a catalyst powder together with a carrier gas onto a surface of a polymer electrolyte film or a porous conductive electrode substrate to adhere said catalyst powder to said surface of said polymer electrolyte film or said porous conductive electrode substrate, thereby to form a layer including the catalyst powder on said surface.  
     
     
         10 . The method of producing an electrode for a fuel cell in accordance with  claim 9 , wherein said catalyst powder is electrostatically-charged.  
     
     
         11 . The method of producing an electrode for a fuel cell in accordance with  claim 9 , wherein said catalyst powder includes a carbon fine powder carrying a noble metal.  
     
     
         12 . The method of producing an electrode for a fuel cell in accordance with  claim 11 , wherein said catalyst powder contains a polymer electrolyte.  
     
     
         13 . The method of producing an electrode for a fuel cell in accordance with  claim 12 , wherein said catalyst powder further includes a carbon fine powder coated with a fluorocarbon resin.  
     
     
         14 . The method of producing an electrode for a fuel cell in accordance with  claim 9 , wherein said catalyst powder has been prepared by mixing a carbon fine powder carrying a noble metal with a colloidal dispersion of a polymer electrolyte and then drying the mixture.  
     
     
         15 . The method of producing an electrode for a fuel cell in accordance with  claim 9 , further comprising the step of adhering said polymer electrolyte film on the layer including said catalyst powder by heating.  
     
     
         16 . The method of producing an electrode for a fuel cell in accordance with  claim 15 , further comprising, in advance to the step of adhering said polymer electrolyte film on the layer including said catalyst powder, the step of applying a polymer electrolyte solution on the surface of said polymer electrolyte film to be adhered and then drying.  
     
     
         17 . An electrode for a fuel cell comprising an electrode formed by adhering an electrostatically-charged catalyst powder to at least one surface of a polymer electrolyte film or a porous conductive electrode substrate.  
     
     
         18 . The electrode for a fuel cell in accordance with  claim 17 , wherein said catalyst powder includes at least one selected from a group consisting of a carbon fine powder carrying a noble metal, a mixture of a carbon fine powder carrying a noble metal with a polymer electrolyte, or a mixture of a carbon fine powder carrying a noble metal with a carbon fine powder which has been subjected to a water-repelling treatment with a fluorocarbon resin and a polymer electrolyte.  
     
     
         19 . The electrode for a fuel cell in accordance with  claim 17 , wherein said catalyst powder has been prepared by mixing a colloidal dispersion of a polymer electrolyte with a carbon fine powder carrying a noble metal, and then drying.  
     
     
         20 . An electrode for a fuel cell comprising an electrode formed by spraying a catalyst powder onto at least one surface of a polymer electrolyte film or a porous conductive electrode substrate together with a carrier gas.  
     
     
         21 . The electrode for a fuel cell in accordance with  claim 20 , wherein said catalyst powder includes at least one selected from a group consisting of a carbon fine powder carrying a noble metal, a mixture of a carbon fine powder carrying a noble metal with a polymer electrolyte, and a mixture of a carbon fine powder carrying a noble metal with a carbon fine powder which has been subjected to a water-repelling treatment with a fluorocarbon resin and a polymer electrolyte.  
     
     
         22 . The electrode for a fuel cell in accordance with  claim 20 , wherein said catalyst powder has been prepared by mixing a colloidal dispersion of a polymer electrolyte with a carbon fine powder carrying a noble metal, and then drying.