Membrane catalyst layer assembly with reinforcing films, membrane electrode assembly with reinforcing films, and polymer electrolyte fuel cells

Abstract

A membrane-catalyst layer assembly with reinforcing films including a solid polymer electrolyte membrane 2 , a catalyst layer 3 formed on each surface of the electrolyte membrane 2 , and a reinforcing film 4 located on each surface of a membrane-catalyst layer assembly having the electrolyte membrane and the catalyst layers. Each of the reinforcing films 4 has a frame shape with a central opening 41 . Each of the catalyst layers 3 , except for an outer edge portion 31 , is exposed through the opening 41 . Each reinforcing film 4 has a first bonding layer 43 bonded to a membrane-catalyst layer assembly 10 , and a gas barrier layer 42 formed on the first bonding layer 43 to prevent passage of a fuel gas and an oxidant gas.

What is claimed is: 
     
         1 . A membrane-catalyst layer assembly with reinforcing films comprising:
 a solid polymer electrolyte membrane;   a catalyst layer formed on each surface of the electrolyte membrane; and   a frame-shaped reinforcing film with a central opening, the reinforcing film being located on each surface of a membrane-catalyst layer assembly having the electrolyte membrane and the catalyst layers, in such a manner that each catalyst layer, except for an outer edge portion thereof, is exposed through the opening;   each of the reinforcing films comprising a first bonding layer bonded to the membrane-catalyst layer assembly, and a gas barrier layer formed on the first bonding layer to prevent passage of a fuel gas and an oxidant gas.   
     
     
         2 . The membrane-catalyst layer assembly with reinforcing films according to  claim 1 , wherein the first bonding layers are adhesive-bonded to the membrane-catalyst layer assembly. 
     
     
         3 . The membrane-catalyst layer assembly with reinforcing films according to  claim 1 , wherein each of the reinforcing films further comprises a second bonding layer formed on the gas barrier layer, and a gasket is bonded on the second bonding layer. 
     
     
         4 . The membrane-catalyst layer assembly with reinforcing films according to  claim 3 , wherein:
 the first bonding layer is welded to the membrane-catalyst layer assembly;   the second bonding layer is welded to the gasket; and   the first bonding layer has a melting point lower than that of the second bonding layer.   
     
     
         5 . The membrane-catalyst layer assembly with reinforcing films according to  claim 1 , wherein each of the catalyst layers is formed on each surface of the electrolyte membrane, except for an outer edge portion of the electrolyte membrane. 
     
     
         6 . The membrane-catalyst layer assembly with reinforcing films according to  claim 1 , wherein each of the catalyst layers is formed on an entirety of each surface of the electrolyte membrane. 
     
     
         7 . A membrane electrode assembly with reinforcing films comprising:
 the membrane-catalyst layer assembly with reinforcing films of  claim 1 ; and   a gas diffusion layer formed on each of the catalyst layers inside the opening of each reinforcing film, and having a thickness equal to or greater than that of the reinforcing film.   
     
     
         8 . A polymer electrolyte fuel cell comprising:
 the membrane electrode assembly with reinforcing films of  claim 7 ;   a gasket located on each of the reinforcing films so as to surround each electrode having the catalyst layer and the gas diffusion layer; and   a separator located on each electrode and each gasket.   
     
     
         9 . A membrane electrode assembly with reinforcing films comprising:
 a solid polymer electrolyte membrane;   a catalyst layer formed on each surface of the electrolyte membrane;   a gas diffusion layer formed on each of the catalyst layers; and   a frame-shaped reinforcing film with a central opening, the reinforcing film being located on each surface of the membrane electrode assembly having the electrolyte membrane, catalyst layers, and gas diffusion layers, in such a manner that each gas diffusion layer, except for an outer edge portion thereof, is exposed through the opening;   each of the reinforcing films comprising a first bonding layer bonded to the electrolyte-electrode assembly, and a gas barrier layer formed on the first bonding layer to prevent passage of a fuel gas and an oxidant gas.   
     
     
         10 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein each of the gas barrier layers is made of a polyester resin. 
     
     
         11 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein the first bonding layer is made of a polyolefin resin. 
     
     
         12 . The membrane electrode assembly with reinforcing films according to  claim 11 , wherein the polyolefin resin is an acid-modified polyolefin resin. 
     
     
         13 . The membrane electrode assembly with reinforcing films according to  claim 12 , wherein the acid-modified polyolefin resin is a polyethylene grafted with an unsaturated carboxylic acid. 
     
     
         14 . The membrane electrode assembly with reinforcing films according to  claim 12 , wherein the acid-modified polyolefin resin is a polypropylene grafted with an unsaturated carboxylic acid. 
     
     
         15 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein the first bonding layers are adhesive-bonded to the membrane electrode assembly. 
     
     
         16 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein each of the reinforcing films further comprises a second bonding layer formed on the gas barrier layer, and a gasket is bonded to the second bonding layer. 
     
     
         17 . The membrane electrode assembly with reinforcing films according to  claim 16 , wherein:
 the first bonding layer is welded to the membrane electrode assembly;   the second bonding layer is welded to the gasket; and   the first bonding layer has a melting point lower than that of the second bonding layer.   
     
     
         18 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein each of the catalyst layers is formed on each surface of the electrolyte membrane, except for an outer edge portion of the electrolyte membrane. 
     
     
         19 . The membrane electrode assembly with reinforcing films according to  claim 9 , wherein each of the catalyst layers is formed on an entirety of each surface of the electrolyte membrane. 
     
     
         20 . A polymer electrolyte fuel cell comprising:
 the membrane electrode assembly with reinforcing films of  claim 9 ;   a gasket formed on each of the reinforcing films so as to surround each electrode having the catalyst layer and the gas diffusion layer; and   a separator located on each electrode and each gasket.