Fuel cell and method for the production thereof

Abstract

A fuel cell ( 1 ) has a plate ( 2 ) produced by powder metallurgy which comprises in one piece a porous substrate area ( 4 ) to which the electrochemically active cell layers ( 6 ) are applied, and a gastight edge area ( 5 ) which is provided with gas passages ( 17, 18 ).

1 . A method for producing a fuel cell having a porous substrate ( 4 ) produced by powder metallurgy to which the electrochemically active cell layers ( 6 ) are applied and which is disposed in the central area of a plate ( 2 ) having gas passages ( 17 ,  18 ) provided in the edge area ( 5 ) thereof, the plate ( 2 ) being configured in one piece so as to form a substrate area ( 4 ) and the edge area ( 5 ), and the edge area ( 5 ) being gas-tightly compressed, wherein a planar, powder-metallurgical, porous body ( 24 ) is produced for forming the plate ( 2 ), the edge area of the body ( 24 ) is compressed to the point of gas-tightness and is provided with the gas passages ( 17 ,  18 ), and the electrochemically active cell layers ( 6 ) are applied to the substrate area ( 4 ) of the plate ( 2 ), characterized in that the compression of the edge area of the body ( 24 ) to the edge area ( 5 ) of the plate ( 2 ) is effected by uniaxial pressing or rolling. 
     
     
         2 . The method according to  claim 1 , wherein the electrolyte layer ( 8 ) of the electrochemically active cell layers ( 6 ) borders gas-tightly on the gas-tight edge area ( 5 ) of the plate ( 2 ). 
     
     
         3 . The method according to  claim 1 , wherein the electrolyte layer ( 8 ) of the electrochemically active cell layers ( 6 ) extends with its total circumference at least on a part of the compressed edge area ( 5 ) of the plate ( 2 ). 
     
     
         4 . The method according to  claim 1 , wherein the plate ( 2 ) is connected on the circumference gas-tightly to a contact plate ( 3 ). 
     
     
         5 . The method according to  claim 1 , wherein a powder with a particle size of <150 μm is employed for forming the planar, powder-metallurgical, porous body ( 24 ). 
     
     
         6 . The method according to  claim 1 , characterized in that the porous body ( 24 ) has a porosity of 20 to 60%. 
     
     
         7 . The method according to  claim 1 , characterized in that upon compression a continuous transition is produced between the compressed edge area ( 5 ) and the intermediate substrate area ( 4 ) of the plate ( 2 ). 
     
     
         8 . The method according to  claim 1 , characterized in that the electrolyte layer ( 8 ) of the electrochemically active cell layers ( 6 ) is so applied that it extends at least onto a part of the compressed edge area ( 5 ) of the plate ( 2 ). 
     
     
         9 . The method according to  claim 8 , characterized in that the edge area ( 5 ) of the plate ( 2 ) is roughened before application of the electrolyte layer ( 8 ). 
     
     
         10 . The method according to  claim 1 , wherein the body is first sintered to obtain a porous body, and the compression of the edge area of the body ( 24 ) to the edge area ( 5 ) of the plate ( 2 ) is then effected by uniaxial pressing or rolling.