Membrane electrode assembly for electrochemical cell

Abstract

Disclosed is a membrane electrode assembly that includes a polymer electrolyte membrane, a first electrochemical reaction layer formed on one side of the polymer electrolyte membrane to allow an oxidation reaction to occur thereon, a first electron-conductive layer formed between the polymer electrolyte membrane and the first electrochemical reaction layer, a second electrochemical reaction layer formed on a remaining side of the polymer electrolyte membrane to allow a reduction reaction to occur thereon, and a second electron-conductive layer formed between the polymer electrolyte membrane and the second electrochemical reaction layer. The first electron-conductive layer and the second electron-conductive layer include a porous metal.

What is claimed is: 
     
         1 . A membrane electrode assembly for an electrochemical cell comprising:
 a polymer electrolyte membrane;   a first electrochemical reaction layer formed on one side of the polymer electrolyte membrane to allow an oxidation reaction to occur thereon;   a first electron-conductive layer formed between the polymer electrolyte membrane and the first electrochemical reaction layer;   a second electrochemical reaction layer formed on a remaining side of the polymer electrolyte membrane to allow a reduction reaction to occur thereon; and   a second electron-conductive layer formed between the polymer electrolyte membrane and the second electrochemical reaction layer,   wherein the first electron-conductive layer and the second electron-conductive layer include a porous metal.   
     
     
         2 . The membrane electrode assembly of  claim 1 , wherein the porous metal further includes a coating layer including a platinum group applied on a surface thereof. 
     
     
         3 . The membrane electrode assembly of  claim 1 , wherein the first electron-conductive layer and the second electron-conductive layer each have a thickness of 0.1 to 1 mm. 
     
     
         4 . The membrane electrode assembly of  claim 1 , wherein the first electron-conductive layer and the second electron-conductive layer include any one among platinum, palladium, rhodium, iridium, ruthenium, osmium, carbon, gold, tantalum, tin, indium, nickel, tungsten, manganese, and titanium, or a complex including two or more thereof. 
     
     
         5 . The membrane electrode assembly of  claim 1 , wherein the first electrochemical reaction layer and the second electrochemical reaction layer each includes an electrochemical catalyst (or the electrochemical catalyst on a carrier), an ionic conductor, and a binder. 
     
     
         6 . The membrane electrode assembly of  claim 5 , wherein the electrochemical catalyst includes any one among platinum group elements including platinum, palladium, ruthenium, iridium, rhodium, and osmium, any one metal among iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, and aluminum, or alloys, oxides, or double oxides thereof. 
     
     
         7 . The membrane electrode assembly of  claim 1 , wherein elements constituting the membrane electrode assembly include the polymer electrolyte membrane, the first electron-conductive layer, the second electron-conductive layer, the first electrochemical reaction layer, and the second electrochemical reaction layer in descending order of size.