Electrode structure for polymer electrolyte fuel cell and method for manufacturing the same

Abstract

There is provided an electrode structure for a polymer electrolyte fuel cell having excellent power generation performance and excellent durability and a method for manufacturing the same. Also provided is a polymer electrolyte fuel cell including the electrode structure and an electrical apparatus and a transport apparatus using the polymer electrolyte fuel cell. The electrode structure includes a polymer electrolyte membrane 2 sandwiched between a pair of electrode catalyst layers 1, 1 containing carbon particles supporting catalyst particles. The polymer electrolyte membrane 2 is made of a sulfonated polyarylene-based polymer. The sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq/g, and the polymer contains a component insoluble in N-methylpyrrolidone in an amount of 70% or less relative to the total amount of the polymer, after the polymer is subjected to heat treatment for exposing it under a constant temperature atmosphere of 120° C. for 200 hours. A catalyst paste containing catalyst particles and a polymer electrolyte is coated on a sheet—like support 6 and dried to form an electrode catalyst layer 1 containing a solvent in an amount in the range of 0.5% or less by weight of the total membrane. The electrode catalyst layers 3, 3 are thermally transferred and joined on both sides of the polymer electrolyte membrane 1.

What is claimed is:  
     
         1 . An electrode structure for a polymer electrolyte fuel cell comprising a pair of electrode catalyst layers containing carbon particles supporting platinum particles as a catalyst and a polymer electrolyte membrane sandwiched between the electrode catalyst layers, wherein 
 said polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer;    said sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq/g; and    said polymer contains a component insoluble in N-methylpyrrolidone in an amount of 70% or less relative to the total amount of the polymer, after said polymer is subjected to heat treatment for exposing the same under a constant temperature atmosphere of 120° C. for 200 hours.    
     
     
         2 . The electrode structure for a polymer electrolyte fuel cell according to  claim 1 , wherein said sulfonated polyarylene-based polymer is a sulfonated product of a copolymer represented by formula (1):  
       
         
           
           
               
               
           
         
       
     
     
         3 . The electrode structure for a polymer electrolyte fuel cell according to  claim 1 , wherein said sulfonated polyarylene-based polymer is a copolymer represented by formula (2):  
       
         
           
           
               
               
           
         
       
     
     
         4 . A method for manufacturing an electrode structure for a polymer electrolyte fuel cell comprising a pair of electrode catalyst layers containing carbon particles supporting platinum particles as a catalyst and a polymer electrolyte membrane sandwiched between the electrode catalyst layers, wherein said polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer, comprising the steps of: 
 forming a polymer electrolyte membrane from a solution of a sulfonated polyarylene-based polymer;    coating a catalyst paste containing catalyst particles in which platinum particles are supported on carbon particles and a polymer electrolyte on a sheet-like support and drying the same to form an electrode catalyst layer; and    thermally transferring to join said electrode catalyst layer to both sides of the polymer electrolyte membrane containing a solvent in the range of 0.5% or less by weight of the total membrane.    
     
     
         5 . The method for manufacturing an electrode structure for a polymer electrolyte fuel cell according to  claim 4 , wherein said sulfonated polyarylene-based polymer is a sulfonated product of a copolymer represented by formula (1):  
       
         
           
           
               
               
           
         
       
     
     
         6 . The method for manufacturing an electrode structure for a polymer electrolyte fuel cell according to  claim 4 , wherein said sulfonated polyarylene-based polymer is a copolymer represented by formula (2):  
       
         
           
           
               
               
           
         
       
     
     
         7 . A polymer electrolyte fuel cell comprising an electrode structure for a polymer electrolyte fuel cell comprising a pair of electrode catalyst layers containing carbon particles supporting platinum particles as a catalyst and a polymer electrolyte membrane sandwiched between the electrode catalyst layers, wherein 
 said polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer;    said sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq/g; and    said polymer contains a component insoluble in N-methylpyrrolidone in an amount of 70% or less relative to the total amount of the polymer, after said polymer is subjected to heat treatment for exposing the same under a constant temperature atmosphere of 120° C. for 200 hours.    
     
     
         8 . An electrical apparatus using a polymer electrolyte fuel cell comprising an electrode structure for a polymer electrolyte fuel cell comprising a pair of electrode catalyst layers containing carbon particles supporting platinum particles as a catalyst and a polymer electrolyte membrane sandwiched by the electrode catalyst layers, wherein 
 said polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer;    said sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq/g; and    said polymer contains a component insoluble in N-methylpyrrolidone in an amount of 70% or less relative to the total amount of the polymer, after said polymer is subjected to heat treatment for exposing the same under a constant temperature atmosphere of 120° C. for 200 hours.    
     
     
         9 . A transport apparatus using a polymer electrolyte fuel cell comprising an electrode structure for a polymer electrolyte fuel cell comprising a pair of electrode catalyst layers containing carbon particles supporting platinum particles as a catalyst and a polymer electrolyte membrane sandwiched by the electrode catalyst layers, wherein 
 said polymer electrolyte membrane is made of a sulfonated polyarylene-based polymer;    said sulfonated polyarylene-based polymer has an ion exchange capacity in the range of 1.7 to 2.3 meq/g; and    said polymer contains a component insoluble in N-methylpyrrolidone in an amount of 70% or less relative to the total amount of the polymer, after said polymer is subjected to heat treatment for exposing the same under a constant temperature atmosphere of 120° C. for 200 hours.