Membrane electrode assemblies for use in fuel cells

Abstract

Electrocatalyst powders and methods for producing electrocatalyst powders, such as carbon composite electrocatalyst powders. The powders have a well-controlled microstructure and morphology. The method includes forming the particles from an aerosol of precursors by heating the aerosol to a relatively low temperature, such as not greater than about 400° C.

1 - 81 . (canceled) 
   
   
       82 . An energy device, comprising an anode, a cathode and an electrolyte separating the anode and the cathode, wherein the cathode comprises a current collector, a catalyst layer and a conductive layer separating the current collector and the catalyst layer, and wherein the conductive layer comprises carbon particles dispersed in a hydrophobic matrix. 
   
   
       83 . An energy device as recited in  claim 82 , wherein said catalyst layer comprises an oxygen reduction catalyst. 
   
   
       84 . An energy device as recited in  claim 83 , wherein said catalyst layer comprises composite electrocatalyst particles having an active species phase dispersed on a support phase. 
   
   
       85 . An energy device as recited in  claim 84 , wherein said support phase comprises carbon. 
   
   
       86 . An energy device as recited in  claim 85 , wherein said active species phase comprises platinum. 
   
   
       87 . An energy device as recited in  claim 82 , wherein said hydrophobic matrix comprises a fluorocarbon polymer. 
   
   
       88 . An energy device as recited in  claim 82 , wherein said hydrophobic matrix comprises a tetrafluorethylene fluorocarbon polymer. 
   
   
       89 . An energy device as recited in  claim 82 , wherein said electrolyte is a polymer electrolyte. 
   
   
       90 . An energy device as recited in  claim 82 , wherein said current collector, said catalyst layer and said conductive layer have a total thickness of not greater than about 100 μm. 
   
   
       91 . An energy device as recited in  claim 82 , wherein said carbon particles have an average particle size of not greater than about 10 μm. 
   
   
       92 . An energy device as recited in  claim 82 , wherein said energy device is a fuel cell.