Method of manufacturing membrane electrode assembly and method of manufacturing fuel cell

Abstract

Provided is a method of manufacturing a membrane electrode assembly including catalyst layers in both sides of a polymer electrolyte membrane, substance diffusion of the catalyst layer being improved, in which forming at least one of the catalyst layers includes at least: forming a first layer including one of a catalyst and a catalyst precursor on a surface of a sheet by vapor-phase deposition; forming a through hole in the first layer; forming a second layer including one of a catalyst and a catalyst precursor on a surface of the first layer having the through hole by vapor-phase deposition; joining a polymer electrolyte membrane to a surface of the second layer; and peeling off the sheet from the first layer.

1 . A method of manufacturing a membrane electrode assembly including catalyst layers formed on both sides of a polymer electrolyte membrane comprising:
 forming a first layer including one of a catalyst and a catalyst precursor on a surface of a sheet by vapor-phase deposition;   forming a through hole in the first layer;   forming a second layer including one of a catalyst and a catalyst precursor on a surface of the first layer having the through hole by vapor-phase deposition;   joining a polymer electrolyte membrane to a surface of the second layer; and   removing the sheet from the first layer.   
     
     
         2 . The method of manufacturing the membrane electrode assembly according to  claim 1 , wherein the forming a through hole in the first layer comprises forming a through hole so that an opening ratio of a surface of the first layer in contact with the sheet is 8% or more to 40% or less. 
     
     
         3 . The method of manufacturing a membrane electrode assembly according to  claim 1 , wherein the forming a through hole in the first layer comprises forming a through hole so that one of the catalyst and the catalyst precursor in the first layer remains at 50 μg or more per 1 cm 2  of a surface area of the sheet after the forming the through hole. 
     
     
         4 . The method of manufacturing a membrane electrode assembly according to  claim 1 , further comprising, before the forming a first layer, forming an irregularity on the surface of the sheet,
 wherein the first layer is formed on the surface of the irregularity.   
     
     
         5 . The method of manufacturing a membrane electrode assembly according to  claim 4 , wherein the forming an irregularity on the surface of the sheet includes forming an irregularity of a streaky shape on the surface of the sheet. 
     
     
         6 . The method of manufacturing a membrane electrode assembly according to  claim 4 , wherein the forming an irregularity of a streaky shape on the surface of the sheet comprises one of rubbing and polishing. 
     
     
         7 . The method of manufacturing a membrane electrode assembly according to  claim 4 , wherein the joining a polymer electrolyte membrane to a surface of the second layer comprises joining a second layer formed on a protruded portion of the irregularity and at least a part of a second layer formed on a recessed portion of the irregularity to the polymer electrolyte membrane. 
     
     
         8 . The method of manufacturing a membrane electrode assembly according to  claim 1 , wherein the through hole is formed by dry etching. 
     
     
         9 . The method of manufacturing a membrane electrode assembly according to  claim 1 , further comprising reducing PtOx (x≧2),
 wherein the first layer comprises one of platinum and a platinum oxide, and the second layer includes the PtOx (x≧2).   
     
     
         10 . The method for a membrane electrode assembly according to  claim 9 , wherein by the reducing PtOx (x≧2), a catalyst layer of a dendritic shape is formed. 
     
     
         11 . A method of manufacturing a fuel cell, comprising:
 manufacturing a membrane electrode assembly by the method of manufacturing a membrane electrode assembly according to  claim 1 ; and   forming gas diffusion layers on both sides of the membrane electrode assembly.