Multilayer electrochemical cell technology using sol-gel processing applied to ceramic oxygen generator

Abstract

An electrochemical cell that receives an inlet stream of air and produces an outlet stream of a high oxygen concentration of gas. The cell is made up of a plurality of layers and preferably a porous electrolyte comprised of yttria stabilized zirconia (YSZ) that allows only oxygen ions to pass therethrough and which is covered on its sides with electrodes comprised of lanthanum strontium manganate (LSM) which in turn are coated with a layer of platinum to aid in the even distribution of the electrical current. An electrical current is passed through the electrodes to produce a voltage difference therebetween. The layers of YSZ and LSM are formed by a sol-gel process.

1 . An electrochemical oxygen cell for producing a gas having a high oxygen concentration, said electrochemical oxygen cell comprising a substrate, an anodic electrode layer of lanthanum strontium manganate covering said substrate, an electrolyte layer comprised of yttria stabilized zirconia covering said anodic electrode layer, and a cathodic electrode layer of lanthanum strontium manganate covering said electrolyte layer, said electrochemical cell having an inlet for air to enter said electrochemical oxygen cell through said cathodic electrode layer and an outlet for the high oxygen concentration gas to emerge from said electrochemical cell from said anodic electrode, said anodic electrode layer and said cathodic electrode layer adapted to be connected to a source of electrical energy to cause the flow of air through said electrochemical cell. 
     
     
         2 . An electrochemical oxygen cell as defined in  claim 1  wherein said cathodic and anodic electrodes are about 20 microns in thickness. 
     
     
         3 . An electrochemical oxygen cell as defined in  claim 1  wherein said lanthanum strontium manganate layers are applied by the sol-gel process. 
     
     
         4 . An electrochemical oxygen cell as defined in  claim 1  wherein said substrate is an alumina ceramic material. 
     
     
         5 . An oxygen generator for producing a gas having a high oxygen concentration, said oxygen generator comprising a substrate, a first platinum layer covering a surface of said substrate, an anodic electrode of LSM covering said first platinum layer, an electrolyte comprised of YSZ covering said first platinum layer, a cathodic layer of LSM covering said electrolyte and a second platinum layer covering said cathodic layer, an inlet for air to enter said oxygen generator through said second platinum layer and an outlet for an enriched oxygen gas to emerge from said electrochemical cell for said first platinum layer, wherein said first and second platinum layers are adapted to be connected to a source of electrical energy to cause the flow of air through said electrochemical cell. 
     
     
         6 . An oxygen generator as defined in  claim 5  where said first and second platinum layers comprise a thinned platinum paste applied in a plurality of coats. 
     
     
         7 . An oxygen generator as defined in  claim 6  wherein certain of said coats are heat treated. 
     
     
         8 - 22 . (canceled)