Electrode for use in a capacitor

Abstract

A deposition process for coating a substrate with a ruthenium-containing oxide material, or a precursor thereof, is described. Preferably, the reagent solution is substantially devoid of a halide, such as chlorine. The coated substrate is useful as an electrode in a capacitor.

What is claimed is:  
     
         1 . An electrode component, which comprises: 
 a) a substrate having a surface to be coated; and    b) a ruthenium-containing oxide compound coated thereon, wherein the coating is characterized as having been formed from a solution comprising a solvent having a precursor of the ruthenium-containing oxide compound dissolved therein and contacted to the substrate, the substrate having been heated to evaporate the solvent and convert the precursor to the ruthenium-containing oxide compound coated on the substrate surface, and wherein the precursor is substantially devoid of a halide.    
     
     
         2 . The electrode component of  claim 1  wherein the precursor is selected from the group consisting of ruthenium(III) nitrosyl nitrate, nitrosyl ruthenium(III) acetate, nitrosyl ruthenium(III) sulfate, ruthenium(III) 2,4-pentanedionate, and mixtures thereof.  
     
     
         3 . A method for providing an electrode component, comprising the steps of: 
 a) providing a substrate having a surface to be coated;    b) providing a solution comprising a solvent having a precursor for a ruthenium-containing oxide compound dissolved therein, wherein the precursor is substantially devoid of a halide; and    c) contacting the substrate with the solution, wherein the substrate is heated to a temperature sufficient to at least partially evaporate the solvent and to instantaneously convert at least some of the precursor to a ruthenium-containing oxide compound coated on the substrate surface.    
     
     
         4 . The method of  claim 3  including selecting the precursor from the group consisting of ruthenium(III) nitrosyl nitrate, nitrosyl ruthenium(III) acetate, nitrosyl ruthenium(III) sulfate, ruthenium(III) 2,4-pentanedionate, and mixtures thereof.  
     
     
         5 . The method of  claim 3  including contacting the solution to the substrate by one of dipping, painting, doctor-blading, pressurized air atomization spraying, aerosolized spraying, and sol-gel deposition.  
     
     
         6 . A method for providing an electrode component, comprising the steps of: 
 a) providing a substrate having a surface to be coated;    b) providing a solution comprising either an aqueous solvent or an alcohol solvent, or a mixture thereof, having a precursor of a ruthenium-containing oxide compound, wherein the precursor is substantially devoid of a halide;    c) contacting the substrate with the solution; and    d) heating the substrate to evaporate the solvent and convert the precursor, thereby forming a coating of the ruthenium-containing oxide compound on the substrate surface.    
     
     
         7 . The method of  claim 6  including selecting the precursor of the ruthenium-containing oxide compound from the group consisting of a nitrate, acetate, sulfate, organic salt, and mixtures thereof.  
     
     
         8 . The method of  claim 6  including selecting the precursor from the group consisting of ruthenium(III) nitrosyl nitrate, nitrosyl ruthenium(III) acetate, nitrosyl ruthenium(III) sulfate, ruthenium(III) 2,4-pentanedionate, and mixtures thereof.  
     
     
         9 . The method of  claim 6  including contacting the solution to the substrate by one of dipping, painting, doctor-blading, pressurized air atomization spraying, aerosolized spraying, and sol-gel deposition.  
     
     
         10 . The method of  claim 6  wherein the substrate is heated to a temperature of at least about 100° C. for the aqueous solution and at least about 70° C. for an alcohol solution.  
     
     
         11 . The method of  claim 6  including providing the coating having a majority of its particles having diameters of less than about 10 microns.  
     
     
         12 . The method of  claim 6  including providing an internal surface area of the coating of about 10 m 2 /gram to about 1,500 m 2 /gram.  
     
     
         13 . The method of  claim 6  including providing the coating having a thickness of about a hundred Angstroms to about 0.1 millimeters.  
     
     
         14 . The method of  claim 6  including providing a second metal in the solution.  
     
     
         15 . The method of  claim 14  including selecting the second metal from the group consisting of tantalum, titanium, nickel, iridium, platinum, palladium, gold, silver, cobalt, molybdenum, ruthenium, manganese, tungsten, iron, zirconium, hafnium, rhodium, vanadium, osmium, niobium, and mixtures thereof.  
     
     
         16 . The method of  claim 6  including selecting the substrate from the group consisting of tantalum, titanium, nickel, molybdenum, niobium, cobalt, stainless steel, tungsten, platinum, palladium, gold, silver, copper, chromium, vanadium, aluminum, zirconium, hafnium, zinc, iron, and mixtures thereof.  
     
     
         17 . The method of  claim 6  including increasing the surface area of the substrate surface prior to contacting the solution to the substrate.  
     
     
         18 . The method of  claim 17  including increasing the substrate surface area by at least one of the group consisting of rough threading, grit blasting, scraping, plasma etching, abrading, wire brushing, and acid contact.  
     
     
         19 . The method of  claim 6  including increasing the electrical conductivity of the surface of the substrate prior to contacting the solution thereto.  
     
     
         20 . The method of  claim 6  including providing the substrate having a thickness of about 0.001 to about 2 millimeters.